Intercepting palladacycles derived by C-H insertion. A mechanism-driven entry to heterocyclic tetraphenylenes

Journal of the American Chemical Society

Volumn 128, Issue 3, 2006, Pages 694-695

  Masselot, David ^a   Charmant, Jonathan P H ^a   Gallagher, Timothy ^a  

^a UNIVERSITY OF BRISTOL   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

CARBON; HETEROCYCLIC COMPOUND; HYDROGEN; PALLADACYCLE; PALLADIUM; PHENYL GROUP; TETRAPHENYLENE DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; CATALYSIS; CHEMICAL BOND; CHROMATOGRAPHY; CRYSTAL STRUCTURE; DERIVATIZATION; DIMERIZATION; HECK REACTION; ISOMERISM; OXIDATION REDUCTION REACTION; REACTION ANALYSIS; SUBSTITUTION REACTION; SYNTHESIS; X RAY CRYSTALLOGRAPHY;

EID: 31444448075     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja056964d     Document Type: Article

References (38)

1. Karig, G.; Moon, M. T.; Thasana, N.; Gallagher, T. Org. Lett. 2002, 4, 3115-3118. Products 3 and 4 are also obtained with the isomeric biaryl halides (i.e., 1-substituted 3-bromo-4-(4′-pyridyl)benzenes). In these cases, the ratio of expected to crossover adducts is not dependent on the nature of the X substituent.
2. This crossover process was subsequently reported for other biaryls: (a) Campo, M. A.; Larock, R. C. J. Am. Chem. Soc. 2002, 124, 14326-14327.
3. For other, related Pd-mediated migration processes, see: (b) Campo, M. A.; Huang, Q. H.; Yao, T. L.; Tian, Q. P.; Larock, R. C. J. Am. Chem. Soc. 2003, 125, 11506-11507.
4. (c) Huang, Q. H.; Campo, M. A.; Yao, T. L.; Tian, Q. P.; Larock, R. C. J. Org. Chem. 2004, 69, 8251-8257.
5. (d) Huang, Q. H.; Fazio, A.; Dai, G. X.; Campo, M. A.; Larock, R. C. J. Am. Chem. Soc. 2004, 126, 7460-7461.
6. For an earlier example of products derived by a formal Pd migration within a biaryl system, see: (e) Rice, J. E.; Cai, Z. W. J. Org. Chem. 1993, 58, 1415-1424.
7. Reviews: (a) Handbook of CH Transformations; Dyker, G., Ed.; Wiley-VCH: Weinheim, Germany, 2005.
8. (b) Jia, C. G.; Kitamura, T.; Fujiwara, Y. Acc. Chem. Res. 2001, 34, 633-639.
9. (c) Dyker, G. Angew. Chem., Int. Ed. 1999, 38, 1699-1712.
10. (d) Ryabov, A. D. Chem. Rev. 1990, 90, 403-424.
11. For other studies involving intramolecular palladium-catalyzed arylations other than with biaryls, see: (a) Campeau, L.-C.; Parisien, M.; Leblanc, M.; Fagnou, K. J. Am. Chem. Soc. 2004, 126, 9186-9187.
12. (b) Gómez-Lor, B.; González-Cantalapiedra, E.; Ruiz, M.; de Frutos, O.; Cárdenas, D. J.; Santos, A.; Echavarren, A. M. Chem. Eur. J. 2004, 10, 2601-2608.
13. For studies relating to EAS versus other mechanistic options associated with palladacycle formation, see: (a) González, J. J.; García, N.; Gómez-Lor, B.; Echavarren, A. M. J. Org. Chem. 1997, 62, 1286-1291.
14. (b) Martín-Matute, B.; Mateo, C.; Cárdenas, D. J.; Echavarren, A. M. Chem. Eur. J 2001, 7, 2341-2348.
15. (c) Gómez-Lor, B.; Echavarren, A. M. Org. Lett. 2004, 6, 2993-2996.
16. For recent computational studies of C-H insertions that favor an agostic C-H complex and do not invoke EAS or Pd(IV), see: (d) Mota, A. J.; Dedieu, A.; Bour, C.; Suffert, J. J. Am. Chem. Soc. 2005, 127, 7171-7182.
17. (e) Davies, L. D.; Donald, S. M. A.; Macgregor, S. A. J. Am. Chem. Soc. 2005, 127, 13754-13755.
18. 4. This metallacycle undergoes the Heck reaction (as Scheme 1) leading to both 3a and 4a but decomposes under conditions required for tetraphenylene formation.
19. (a) Edelbach, B. L.; Lachicotte, R. J.; Jones, W. D. J. Am. Chem. Soc. 1998, 120, 2843-2853.
20. Jones has shown that palladacycle 6 undergoes Heck and Suzuki couplings: (b) Satoh, T.; Jones, W. D. Organometallics 2001, 20, 2916-2919.
21. Palladacycles based on a biaryl scaffold (cf 6) have been characterized by X-ray crystallography: (a) Retbøll, M.; Edwards, A. J.; Rae, A. D.; Willis, A. C.; Bennett, M. A.; Wenger, E. J. Am. Chem. Soc. 2002, 124, 8348-8360. Similar metallacycles have been implicated in the Pd(0)-mediated cyclotrimerization of benzynes:
22. (b) Peña, D.; Escudero, S.; Pérez, D.; Guitián, E.; Castedo, L. Angew. Chem., Int. Ed. 1998, 37, 2659-2661.
23. (a) Wuckert, E.; Dix, M.; Laschat, S.; Baro, A.; Schulte, J. L.; Hägele, C.; Giesselmann, F. Liq. Cryst. 2004, 31, 1305-1309.
24. (b) Marsella, M. J. Acc. Chem. Res. 2002, 35, 944-951.
25. Mak, T. C. W.; Wong, H. N. C. Comprehensive Supramolecular Chemistry; MacNicol, D. D., Toda, F., Bishop, P., Eds.; Pergamon: Oxford, 1996; Vol. 6, pp 351-369.
26. For more recent approaches to substituted tetraphenylenes, see: (a) Peng, H. Y.; Lam, C. K.; Mak, T. C. W.; Cai, Z. W.; Ma, W. T.; Li, Y. X.; Wong, H. N. C. J. Am. Chem. Soc. 2005, 127, 9603-9611.
27. (b) Wen, J. F.; Hong, W.; Yuan, K.; Mak, T. C. W.; Wong, H. N. C. J. Org. Chem. 2003, 68, 8918-8931.
28. Lai, C. W.; Lam, C. K.; Lee, H. K.; Mak, T. C. W.; Wong, H. N. C. Org. Lett. 2003, 5, 823-826.
29. Kabir, S. M. H.; Hasegawa, M.; Kuwatani, Y.; Yoshida, M.; Matsuyama, H.; Iyoda, M. J. Chem. Soc., Perkin Trans. 1 2001, 159-165.
30. Heterocyclic tetraphenylenes incorporating furan, thiophene, pyrazine, pyrimidine, pyrazole, and pyridone units are known. (a) Marsella, M. J.; Reid, R. J.; Estassi, S.; Wang, L.-S. J. Am. Chem. Soc. 2002, 124, 12507-12510.
31. (b) Brettreich, M.; Bendikov, M.; Chaffins, S.; Perepichka, D. F.; Dautel, O.; Duong, H.; Helgeson, R.; Wudl, F. Angew. Chem., Int. Ed. 2002, 41, 3688-3691.
32. Zhou, Z. H.; Yamamoto, T. J. Organomet. Chem. 1991, 414, 119-127.
33. Kauffmann, T.; Greving, B.; Kriegesmann, R.; Mitschker, A.; Woltermann, A. Chem. Ber. 1978, 111, 1330-1336 and references therein.
34. (a) An excess of 5 is important to limit C-Br reduction. With 1a, the mass balance is made up of 8a (36%) and 9 (55%).
35. 7 has shown that 6 derived from 5 participates in Heck reactions, and our control experiment indicates that 1a undergoes oxidative addition more rapidly than 5.
36. (c) We did not observe 7, 8a, or 9 under these Heck conditions, and increasing the concentration of 5 made no impact. This control reaction (see Supporting Information) also shows an induction period prior to consumption of 1a, and addition of liquid mercury to this Heck process very significantly reduced the rate of reaction of 1a. The implications of this are not clear; the active catalyst is not immediately present, and mercury is either preventing the formation of or removing the catalytically competent Pd species. For a related application of a catalytic species derived from Pd black, see: Campeau, L.-C.; Thansandote, P.; Fagnou, K. Org. Lett. 2005, 7, 1857-1860.
37. A more open-ended question relates to how the Pd insertion into biphenylene might be accelerated. This has implications for the efficiency of formation of tetraphenylenes 8.
38. 1 (the regioisomer of 1b). While this establishes an alternative entry to a common palladacycle (2b), these isomeric halides are synthetically less readily accessible than 1.