On the question of stability, conjugation, and "aromaticity" in imidazol-2-ylidenes and their silicon analogs

Journal of the American Chemical Society

Volumn 118, Issue 8, 1996, Pages 2023-2038

  Heinemann, Christoph ^a   Müller, Thomas ^b   Apeloig, Yitzhak ^b   Schwarz, Helmut ^a  

^a TECHNISCHE UNIVERSITÄT BERLIN   (Germany)

^b TECHNION ISRAEL INSTITUTE OF TECHNOLOGY   (Israel)

Author keywords

[No Author keywords available]

Indexed keywords

IMIDAZOLE DERIVATIVE; SILANE DERIVATIVE;

ARTICLE; DRUG STRUCTURE; THERMODYNAMICS;

EID: 0029987178     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja9523294     Document Type: Article

References (120)

1. For example: (a) Leopold, D. G.; Murray, K. K.; Lineberger, W. C. J. Chem. Phys. 1984, 81, 1048. (b) Srinivas, R.; Bohme, D. K.; Schwarz, H. J. Phys. Chem. 1993, 97, 13643. (c) McGibbon, G. A.; Kingsmill, C. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 222, 129. (d) Burgers, P. C.; McGibbon, G. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 224, 539 (e) McGibbon, G. A.; Burgers, P. C.; Terlouw. J. K. Int. J. Mass Specirom. Ion Processes 1994, 136, 191.
2. For example: (a) Leopold, D. G.; Murray, K. K.; Lineberger, W. C. J. Chem. Phys. 1984, 81, 1048. (b) Srinivas, R.; Bohme, D. K.; Schwarz, H. J. Phys. Chem. 1993, 97, 13643. (c) McGibbon, G. A.; Kingsmill, C. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 222, 129. (d) Burgers, P. C.; McGibbon, G. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 224, 539 (e) McGibbon, G. A.; Burgers, P. C.; Terlouw. J. K. Int. J. Mass Specirom. Ion Processes 1994, 136, 191.
3. For example: (a) Leopold, D. G.; Murray, K. K.; Lineberger, W. C. J. Chem. Phys. 1984, 81, 1048. (b) Srinivas, R.; Bohme, D. K.; Schwarz, H. J. Phys. Chem. 1993, 97, 13643. (c) McGibbon, G. A.; Kingsmill, C. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 222, 129. (d) Burgers, P. C.; McGibbon, G. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 224, 539 (e) McGibbon, G. A.; Burgers, P. C.; Terlouw. J. K. Int. J. Mass Specirom. Ion Processes 1994, 136, 191.
4. For example: (a) Leopold, D. G.; Murray, K. K.; Lineberger, W. C. J. Chem. Phys. 1984, 81, 1048. (b) Srinivas, R.; Bohme, D. K.; Schwarz, H. J. Phys. Chem. 1993, 97, 13643. (c) McGibbon, G. A.; Kingsmill, C. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 222, 129. (d) Burgers, P. C.; McGibbon, G. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 224, 539 (e) McGibbon, G. A.; Burgers, P. C.; Terlouw. J. K. Int. J. Mass Specirom. Ion Processes 1994, 136, 191.
5. For example: (a) Leopold, D. G.; Murray, K. K.; Lineberger, W. C. J. Chem. Phys. 1984, 81, 1048. (b) Srinivas, R.; Bohme, D. K.; Schwarz, H. J. Phys. Chem. 1993, 97, 13643. (c) McGibbon, G. A.; Kingsmill, C. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 222, 129. (d) Burgers, P. C.; McGibbon, G. A.; Terlouw, J. K. Chem. Phys. Lett. 1994, 224, 539 (e) McGibbon, G. A.; Burgers, P. C.; Terlouw. J. K. Int. J. Mass Specirom. Ion Processes 1994, 136, 191.
6. For example: (a) Drahnak, T.; Michl. J.; West, R. J. Am Chem. Soc. 1979, 101, 5527. (b) Maier, G.: Glatthaar, J.: Reisenauer, H. P. Chem. Ber. 1989, 122, 2403. (c) Gillette, G. R.; Noren, G.; West, R. Organometallics 1990, 9, 2925. (d) Veith, M.; Werle, E.; Lisowski, R.; Löppe, R.; Schnöckel, H. Chem. Ber. 1992, 125, 1375.
7. For example: (a) Drahnak, T.; Michl. J.; West, R. J. Am Chem. Soc. 1979, 101, 5527. (b) Maier, G.: Glatthaar, J.: Reisenauer, H. P. Chem. Ber. 1989, 122, 2403. (c) Gillette, G. R.; Noren, G.; West, R. Organometallics 1990, 9, 2925. (d) Veith, M.; Werle, E.; Lisowski, R.; Löppe, R.; Schnöckel, H. Chem. Ber. 1992, 125, 1375.
8. For example: (a) Drahnak, T.; Michl. J.; West, R. J. Am Chem. Soc. 1979, 101, 5527. (b) Maier, G.: Glatthaar, J.: Reisenauer, H. P. Chem. Ber. 1989, 122, 2403. (c) Gillette, G. R.; Noren, G.; West, R. Organometallics 1990, 9, 2925. (d) Veith, M.; Werle, E.; Lisowski, R.; Löppe, R.; Schnöckel, H. Chem. Ber. 1992, 125, 1375.
9. For example: (a) Drahnak, T.; Michl. J.; West, R. J. Am Chem. Soc. 1979, 101, 5527. (b) Maier, G.: Glatthaar, J.: Reisenauer, H. P. Chem. Ber. 1989, 122, 2403. (c) Gillette, G. R.; Noren, G.; West, R. Organometallics 1990, 9, 2925. (d) Veith, M.; Werle, E.; Lisowski, R.; Löppe, R.; Schnöckel, H. Chem. Ber. 1992, 125, 1375.
10. (a) Arduengo, A. J., III; Harlow, R. L.; Kline, M. J. Am. Chem. Soc. 1991, 113, 361.
11. (b) Arduengo, A. J., III; Rasika Dias, H V.; Harlow, R. L.; Kline, M. J. Am. Chem. Soc. 1992, 114, 5530.
12. (c) For a brief review, see: Reeitz, M. Angew. Chem. 1991, 103, 691: Angew. Chem.. Int. Ed. Engl. 1991, 30, 674.
13. (c) For a brief review, see: Reeitz, M. Angew. Chem. 1991, 103, 691: Angew. Chem.. Int. Ed. Engl. 1991, 30, 674.
14. Arduengo, A. J.. III: Goerlich, J. R.; Marshall, W. J. J. Am. Chem. Soc. 1995, 117, 11027.
15. Denk, M.; Lennon, R., Hayashi, R.; West, R.; Belyakov, A. V., Verne, H. P.; Haaland, A.; Wagner M.: Metzler, N. J. Am. Chem. Soc. 1994, 116, 2691.
16. Denk, M.: Green, J. C.: Metzler, N.: Wagner, M. J. Chem. Soc., Dalton Trans. 1994, 2405
17. Arduengo, A. J., III; Rasika Dias, H. V.; Dixon, D. A.; Harlow, R. L.; Klooster, W. T.; Koetzle, T. F. J. Am. Chem. Soc. 1994, 116, 6812.
18. Arduengo, A. J., III; Dixon, D. A.; Harlow, Kumashiro. K. K.; Lee, C.; Power, W. P.; Zilm, K. W. J. Am. Chem. Soc. 1994, 116, 6361.
19. Arduengo, A. J., III; Bock, H.; Chen, H.; Denk, M.; Dixon, D. A.; Green, J. C.; Herrmann, W. A.; Jones, N. L ; Wagner, M.; West, R. J. Am. Chem. Soc. 1994, 116, 6641.
20. Dixon, D. A.; Arduengo, A. J , III J. Phys. Chem. 1991, 95, 4180.
21. Cioslowski, J. Int. J. Quantum Chem: Quantum Chem. Symp. 1993, 27, 309.
22. Heinemann, C.; Thiel, W. Chem. Phys. Lett. 1994, 277. 11.
23. Apeloig, Y.; Karni, M.; Müller, T. In Organosilicon Chemistry II; VCH: Weinheim, in press.
24. Nyulászi, L.; Kárpáti, T.: Veszprémi. T. J. Am. Chem. Soc. 1994. 116, 7239.
25. Heinemann, C.; Herrmann, W. A.; Thiel, W. J. Organomet. Chem. 1994, 475, 73.
26. (a) Wanzlick, H.-W.; Schikora, E Angew. Chem 1960, 72, 494.
27. (b) Schikora, E. Ph.D. Thesis, Technical University Berlin, D83. 1961.
28. (c) Wanzlick. H.-W. Angew. Chem. 1962. 74, 129.
29. (d) Lemal, D M.; Kawano. K. I. J. Am. Chem. Soc. 1962, 84, 1761.
30. (e) Lemal, D. M.; Lovald, R. A.; Kawano, K. I. J. Am. Chem. Soc. 1964, 86, 2518.
31. (f) Schonherr, H.-J. Ph.D. Thesis, Technical University Berlin, D83, 1970 Besides studies on the C-C-saturated imidazolin-2-ylidenes 2, this work also reports efforts to synthesize the C-C-unsaturated imidazol-2-ylidenes 1. However. upon deprotonation of 1,3-disubstituted imidazolium salts, which is basically the procedure used in refs 3a and 4. no carbenes could be isolated:
32. (g) Schonherr, H.-J.: Wanzlick. H.-W. Chem. Ber. 1970, 103, 1037.
33. Herrmann, W. A.; Denk, M.: Behm, J., Scherer, W.; Klingan, F. R.; Bock. H.: Solouki, B.; Wagner, M. Angew. Chem. 1992, 104. 1489; Angew. Chem., Int. Ed. Engl 1992. 31, 1485.
34. Herrmann, W. A.; Denk, M.: Behm, J., Scherer, W.; Klingan, F. R.; Bock. H.: Solouki, B.; Wagner, M. Angew. Chem. 1992, 104. 1489; Angew. Chem., Int. Ed. Engl 1992. 31, 1485.
35. (a) Schmidt, M. W.; Truong, P. N.; Gordon, M. S. J. Am. Chem. Soc. 1987. 109, 5217.
36. (b) Raabe, G.; Michl, J. In The Chemistry of Organic Silicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: New York, 1989.
37. (c) Apeloig, Y. In The Chemistry of Organic Silicon Compounds, Patai, S., Rappoport, Z., Eds.; Wiley: New York, 1989.
38. (d) Karni, M.; Apeloig, Y. J. Am. Chem. Soc. 1990. 112, 8589.
39. Böhme, C.; Frenking, G. J. Am. Chem. Soc. 1996, 118, 2039-2046.
40. For a recent monograph on this topic, see: Minkin, V I.; Glukhovtsev. M. N.; Simkin, B. Y. Aromaticity and Antiaromaticity: J. Wiley & Sons: New York, 1994.
41. Bader, R. F. W. Atoms in Molecules - A Quantum Theory; Oxford University Press: Oxford, 1990.
42. For a recent application of this theory to the issue of resonance in the allyl cation, neutral, and anion, see: Gobbi. A ; Frenking, G. J. Am. Chem Soc. 1994. 116. 9275. 9287.
43. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
44. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
45. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
46. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
47. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
48. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
49. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
50. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
51. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
52. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
53. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
54. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
55. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
56. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
57. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
58. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
59. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
60. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
61. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
62. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
63. For main-group and transition-metal complexes as well as other new compounds deriving from imidazol-2-ylidene, see, e.g.: (a) Wanzlick, H.-W.; Schönherr, H.-J. Angew. Chem., Int. Ed. Engl. 1968, 7, 141. (b) Öfele, K. J. Organomet. Chem. 1968, 12, P42. (c) Luger, V. P.; Ruban, G. Acta Crystallogr. 1971, B27, 2276. (d) Arduengo, A. J. III; Kline, M.; Calabrese, J. C.; Davidson, F. J. J. Am. Chem. Soc. 1991, 113, 9704. (e) Bonati, F.; Burini, A.; Pietroni, B. R.; Bovio, B. J. Organomet. Chem. 1991, 408, 271. (f) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1992, 114, 9724. (g) Fehlhammer, W. P.; Bliss, P.; Fuchs, J.; Holzmann, G. Z. Naturforsch. B., Chem. Sci. 1992, 47, 79. (h) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F. Inorg. Chem. 1993, 32, 1541. (i) Arduengo, A. J. III; Dias, H. V R.; Davidson, F.; Harlow, R. L. J. Organomet. Chem. 1993, 462, 13. (j) Arduengo, A. J. III; Dias, H. V. R.; Calabrese, J. C.; Davidson, F.; Organometallics 1993, 12, 34505. (k) Öfele, K.; Herrmann, W. A.; Mihalios, D.; Elison, M.; Herdtweck, E.; Scherer, W.; Mink, J. J. Organomet. Chem. 1993, 459, 177. (l) Kuhn, N.; Kratz, T.; Henkel, G. J. Chem. Soc., Chem. Commun. 1993, 1778. (m) Arduengo, A. J., III; Gamper, S. F.; Calabrese, J. C.; Davidson, F. J. Am. Chem. Soc. 1994, 116, 4391. (n) Arduengo, A. J., III; Tamm, M.; Calabrese, J. C. J. Am. Chem. Soc. 1994, 116, 3625. (o) Kuhn, N.; Henkel, G.; Kratz, T. Chem. Ber. 1993, 126, 2047. (p) Arduengo, A. J. III; Tamm, M.; McLain, S. J.; Calabrese, J. C.; Davidson, F.; Marshall, W. J. J. Am. Chem. Soc. 1994, 116, 7927. (q) Schumann, H.; Glanz, M.; Winterfeld, J.; Hemling, H.; Kuhn, N.; Kratz, T. Angew. Chem., Int. Ed. Engl. 1994, 33, 1733. (r) Arduengo, A. J. III; Gamper, S. F.; Tamm, M.; Calabrese, J. C.; Davidson, F.; Craig, H. A. J. Am. Chem. Soc. 1995. 117, 572. (s) Schäfer, A.; Weidenbruch, M.; Saak, W.; Pohl, S. J. Chem. Soc., Chem. Commun. 1995, 1157. (t) Kuhn, N.; Kratz, T.; Blaser, D.; Boese, R. Chem. Ber. 1995, 128, 245. (u) Alder, R. W.; Allen, P. R.; Williams, S. J. J. Chem. Soc., Chem. Commun. 1995, 1267.
64. Recently, a new stable carbene based on the 4,5-dihydro-1H-1,2,4-triazol-5-ylidene ring system has been synthesized: Enders, D.; Breuer, K.; Raabe, G.: Runsink, J.; Teles, J. H.; Melder, J.-P.; Ebel, K.; Brode, S. Angew. Chem. 1995, 107, 1119; Angew. Chem., Int. Ed. Engl. 1995, 34, 1012.
65. Recently, a new stable carbene based on the 4,5-dihydro-1H-1,2,4-triazol-5-ylidene ring system has been synthesized: Enders, D.; Breuer, K.; Raabe, G.: Runsink, J.; Teles, J. H.; Melder, J.-P.; Ebel, K.; Brode, S. Angew. Chem. 1995, 107, 1119; Angew. Chem., Int. Ed. Engl. 1995, 34, 1012.
66. Brown, D. S.; Decken, A.; Cowley, A. H. J. Am. Chem. Soc. 1995, 117, 5421.
67. Tomioka, H.; Watanabe, T., Hirai, K.: Furukawa, K , Takui, T.; Itoh, K. J. Am. Chem. Soc. 1995, 117, 6376.
68. (a) Igau, A.; Grützmacher. H.: Baceiredo, A.; Bertrand, G. J. Am. Chem. Soc. 1988, 110, 6463.
69. (b) Igau, A.; Baceiredo, A.; Trinquier. G.; Bertrand, G. Angew. Chem. 1989, 101, 617; Angew, Chem , Int. Ed Engl. 1989, 28, 621.
70. (b) Igau, A.; Baceiredo, A.; Trinquier. G.; Bertrand, G. Angew. Chem. 1989, 101, 617; Angew, Chem , Int. Ed Engl. 1989, 28, 621.
71. (c) Gilette, G ; Igau, A.; Alcaraz, G.; Wecker, U.; Baceiredo, A.; Dahan, F.: Bertrand. G. Angew. Chem. 1995, 107, 1358.
72. (a) Dixon, D. A.; Dobbs, K. D.; Arduengo. A. J., III: Bertrand, G. J. Am. Chem. Soc. 1991, 113, 8782.
73. (b) Soleilhavoup, M., Baceiredo, A.; Treutler, O.; Ahlrichs, R., Nieger. M: Bertrand, G. J. Am. Chem. Soc. 1992. 114, 10959.
74. (c) Treutler. O.; Ahlrichs, R.: Soleilhavoup, M. J. Am. Chem. S0c. 1993, 115, 8788.
75. (a) Gaussian 92/DFT, Revision F.2, Frisch, M. J.; Trucks, G. W.; Schlegel, H. W.; Gill, P. M. W.; Johnson, B. G.; Wong, M. W.; Foresman, J. B.; Robb, M. A.; Head-Gordon, M.; Replogle, E. S.; Gomperts, R.; Andres, J. L.; Raghavachari, K.; Binkley, J. S.; Gonzales, C.; Martin, R. L., Fox, D. J.; Defrees, D. J.; Baker, J.; Stewart, J. J. P.; Pople. J. A., Gaussian, Inc., Pittsburgh, PA. 1993.
76. (b) Hehre, W. J.; Radom, L.; Schleyer, P. v. R.; Pople, J. A. Ab initio Molecular Orbital Theory; Wiley: NewYork, 1986.
77. Pople, J. A.; Head-Gordon. M.; Raghavachari, K. J. Chem. Phys. 1987, 87, 5968.
78. (a) Schlegel, H. B. J. Chem. Phys. 1986, 84, 4530.
79. (b) Schlegel, H. B. J. Phys. Chem. 1988, 92, 3075.
80. MacDougall, P. J.: Bader, R. F. W. Can. J. Chem. 1986, 64, 1496.
81. For a recent review, see: Kutzelnigg, W.; Fleischer, U.; Schindler, M. NMR Basic Princ. Prog. 1991, 23, 165.
82. (a) Bader. R. F. W. Acc. Chem. Res. 1975, 8, 34.
83. (b) Bader, R F. W. Chem. Rev. 1991. 91, 893.
84. (c) Bader, R. F. W.; Popelier, P. A. L.; Keith, T. A. Angew. Chem. 1994, 106, 647; Angew. Chem., Int. Ed. Engl. 1994, 33, 620.
85. (c) Bader, R. F. W.; Popelier, P. A. L.; Keith, T. A. Angew. Chem. 1994, 106, 647; Angew. Chem., Int. Ed. Engl. 1994, 33, 620.
86. Bader. R. F W.; Slee, T. S.; Cremer, D., Kraka, E. J. Am Chem. Soc 1983. 105. 5061.
87. -, S. NH, and O, respectively, in agreement with their commonly accepted degrees of aromaticity, see: (a) Schleyer, P. v. R.; Freeman, P. K.; Jiao, H.; Goldfuss, B. Angew. Chem. 1995, 107, 332; Angew. Chem., Int. Ed. Engl. 1995, 34, 337. (b) Goldfuss, B.; Schleyer, P. v. R. Organometallics 1995. 14, 1553. In addition, the X-C bonds have their major axes perpendicular to the molecular planes, as typical for bonds with significant π-contriutions.
88. -, S. NH, and O, respectively, in agreement with their commonly accepted degrees of aromaticity, see: (a) Schleyer, P. v. R.; Freeman, P. K.; Jiao, H.; Goldfuss, B. Angew. Chem. 1995, 107, 332; Angew. Chem., Int. Ed. Engl. 1995, 34, 337. (b) Goldfuss, B.; Schleyer, P. v. R. Organometallics 1995. 14, 1553. In addition, the X-C bonds have their major axes perpendicular to the molecular planes, as typical for bonds with significant π-contriutions.
89. -, S. NH, and O, respectively, in agreement with their commonly accepted degrees of aromaticity, see: (a) Schleyer, P. v. R.; Freeman, P. K.; Jiao, H.; Goldfuss, B. Angew. Chem. 1995, 107, 332; Angew. Chem., Int. Ed. Engl. 1995, 34, 337. (b) Goldfuss, B.; Schleyer, P. v. R. Organometallics 1995. 14, 1553. In addition, the X-C bonds have their major axes perpendicular to the molecular planes, as typical for bonds with significant π-contriutions.
90. Bader, R. F. W., MacDougall, P. J.; Lau, C. D. H. J. Am Chem Soc. 1984, 106, 1594.
91. 2r(r).
92. Biegler-König, F. W.; Bader, R. F. W.; Tang, T.-H. J. Comput. Chem. 1982, 3, 317.
93. (a) Keith, T. A.; Bader, R. F. W. J. Chem. Phys. 1993, 99. 3669.
94. (b) Bader, R. F. W.; Keith, T. A. J. Chem. Phys. 1993. 99, 3683.
95. Keith, T. A.; Bader. R. F. W. Chem. Phys. Lett. 1992. 193, 1.
96. Schleyer. P. v. R.; Stout, P. D. J. Chem. Soc.. Chem. Commun. 1986, 1373.
97. 2i structure, but it is still by more than 10 kcal/mol less stabilized compared to the C=C unsaturated cyclocarbene and cyclosily lene (reactions b)
98. Bader, R. F. W. Personal communication.
99. (a) Keith, T. A. Ph.D. Thesis, McMaster University, 1993.
100. (b) Keith, T. A.; Bader, R. F. W., manuscript in preparation.
101. b) - B)}. Using HF/6-311G(d.p)/HF/6-31G(d) wave functions for methylarmine. formimine. and hydrogen cyanide, a least squares fit to bond orders of 1, 2, and 3 yields A = 4.890 and B = 0.270 for C-N bonds.
102. p.r population at the carbene center from HF/6-311G(2d.2p) wave functions: 19a, 0.34 (Mulliken), 0.33 (NBO); 19b, 0.06 (Mulliken), 0.06 (NBO). Atomic charges: 19a, q(C) = -0.14 (Mulliken), q(N) = -0.13 (Mulliken). q(C) = 0.00 (NBO), q(N) = -0.77 (NBO): 19b. q(C) = 0.08 (Mutliken). q(N) = -0.36 (Mulliken), q(C) = 0.25 (NBO), q(N) = -0.96 (NBO).
103. The distance between the bond critical point and the carbenic carbon is 0.433 Å in 19a and 0.590 Å in 19b.
104. 0c contributions. Further details are available from the authors. email: heineman@zrisp5.chem.tu-berlin.de.
105. Wiberg, K. B : Laidig. K. E. J. Am. Chem. Soc 1987, 109, 5935.
106. Gobbi, A.; Frenking, G. J. Am. Chem. Soc. 1993, 115, 2362.
107. Wiberg, K B.; Cheeseman, J. R.; Ochterski, J. W.; Frisch, M. J. J. Am. Chem. Soc. 1995, 117, 6535 and references cited therein.
108. 2 = -0.630).
109. The orientation is chosen such that the molecule lies in the yz plane with the z-axis being the 2-fold axis of rotation.
110. For applications of this concept to substituted benzenes, see: (a) Bader, R. F. W.; Chang, C. J. Phys. Chem 1989, 93, 2946. (b) Bader, R. F. W.; Chang, C. J. Phys. Chem. 1989, 93, 5095. (c) Reference 21, p 205ff.
111. For applications of this concept to substituted benzenes, see: (a) Bader, R. F. W.; Chang, C. J. Phys. Chem 1989, 93, 2946. (b) Bader, R. F. W.; Chang, C. J. Phys. Chem. 1989, 93, 5095. (c) Reference 21, p 205ff.
112. For applications of this concept to substituted benzenes, see: (a) Bader, R. F. W.; Chang, C. J. Phys. Chem 1989, 93, 2946. (b) Bader, R. F. W.; Chang, C. J. Phys. Chem. 1989, 93, 5095. (c) Reference 21, p 205ff.
113. 2 = -0.634).
114. A bis(carbene) proton complex mvolving two imidazol-2-ylidenes has recently been reported: ref 23r
115. Koopmans, T. Physica 1934, 1, 104.
116. 1 orbital as the HOMO of the C=C-unsaturated carbene on the basis of an application of Koopmans' theorem for the Kohn-Sham orbitals of density-functional theory. See: (a) Janak, J. F. Phys. Rev. B 1978, 18, 7165. (b) Slater, J. C Adv. Quantum Chem. 1972, 6. 1. Note that there is a difference in the physical meaning of Hartree-Fock and Kohn-Sham orbital energies. For a discussion of this point. see, for example: (c) Jones, R. O.; Gunnarsson, O. Rev. Mod. Phvs 1989, 61, 689. (d) Parr, R. G.; Yang, W. Density Functional Theory of Atoms and Molecules: Oxford University Press: New York. 1989.
117. 1 orbital as the HOMO of the C=C-unsaturated carbene on the basis of an application of Koopmans' theorem for the Kohn-Sham orbitals of density-functional theory. See: (a) Janak, J. F. Phys. Rev. B 1978, 18, 7165. (b) Slater, J. C Adv. Quantum Chem. 1972, 6. 1. Note that there is a difference in the physical meaning of Hartree-Fock and Kohn-Sham orbital energies. For a discussion of this point. see, for example: (c) Jones, R. O.; Gunnarsson, O. Rev. Mod. Phvs 1989, 61, 689. (d) Parr, R. G.; Yang, W. Density Functional Theory of Atoms and Molecules: Oxford University Press: New York. 1989.
118. 1 orbital as the HOMO of the C=C-unsaturated carbene on the basis of an application of Koopmans' theorem for the Kohn-Sham orbitals of density-functional theory. See: (a) Janak, J. F. Phys. Rev. B 1978, 18, 7165. (b) Slater, J. C Adv. Quantum Chem. 1972, 6. 1. Note that there is a difference in the physical meaning of Hartree-Fock and Kohn-Sham orbital energies. For a discussion of this point. see, for example: (c) Jones, R. O.; Gunnarsson, O. Rev. Mod. Phvs 1989, 61, 689. (d) Parr, R. G.; Yang, W. Density Functional Theory of Atoms and Molecules: Oxford University Press: New York. 1989.
119. 1 orbital as the HOMO of the C=C-unsaturated carbene on the basis of an application of Koopmans' theorem for the Kohn-Sham orbitals of density-functional theory. See: (a) Janak, J. F. Phys. Rev. B 1978, 18, 7165. (b) Slater, J. C Adv. Quantum Chem. 1972, 6. 1. Note that there is a difference in the physical meaning of Hartree-Fock and Kohn-Sham orbital energies. For a discussion of this point. see, for example: (c) Jones, R. O.; Gunnarsson, O. Rev. Mod. Phvs 1989, 61, 689. (d) Parr, R. G.; Yang, W. Density Functional Theory of Atoms and Molecules: Oxford University Press: New York. 1989.
120. Szabo. A.; Ostlund, N. S. Modern Quantum Chemistry; McGraw-Hill: New York, 1982.