Dimerizations of Nitrile Oxides to Furoxans are Stepwise via Dinitrosoalkene Diradicals: A Density Functional Theory Study

Journal of the American Chemical Society

Volumn 125, Issue 50, 2003, Pages 15420-15425

  Yu, Zhi Xiang ^a   Caramella, Pierluigi ^b   Houk, K N ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

^b UNIVERSITY OF PAVIA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

CHEMICAL BONDS; DIMERIZATION; ISOMERIZATION; PROBABILITY DENSITY FUNCTION;

DIRADICAL INTERMEDIATE MECHANISM;

ACETONITRILE;

4 CHLOROBENZONITRILE; ALKENE DERIVATIVE; AROMATIC COMPOUND; FURAZOLIDONE; FUROXAN DERIVATIVE; NITRILE OXIDE; OXIDE; RADICAL; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL BOND; CHEMICAL REACTION; CONJUGATION; DENSITY FUNCTIONAL THEORY; DIMERIZATION; ISOMERIZATION; REACTION ANALYSIS;

EID: 0346850029     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja037325a     Document Type: Article

References (61)

1. For recent reviews, see: (a) Jager, V.; Colinas, P. A. Nitrile Oxides. In Synthetic Applications of 1,3-Dipolar Cycloaddition Chemistry Toward Heterocycles and Natural Products; Padwa, A.; Pearson, W. H., Eds.; John Wiley & Sons Inc.: New York; 2002, Vol. 59, The Chemistry of Heterocyclic Compounds.
2. (b) Caramella, P.; Grunanger, P. Nitrile Oxides and Imines. In 1,3-Dipolar Cycloaddition Chemistry; Padwa, A., Ed.; John Wiley & Sons Inc.: New York, 1984.
3. (c) Grundmann C.; Grunanger, P. The Nitrile Oxides; Springer-Verlag: Berlin, 1971.
4. (a) Speroni, G.; Bartoli, M. Sopra Gli Ossidi di Benzonitrile, Nota VIII; Stabilimento Tipografico Marzocco, Florence, 1952.
5. (b) Morrocchi, S.; Ricca, A.; Selva, A.; Zanarotti, A. Chim. Ind. (Milan) 1968, 50, 558.
6. (c) Morrocchi, S.; Ricca, A.; Selva, A.; Zanarotti, A. Gazz. Chim. Ital. 1969, 99, 165.
7. (d) De Sarlo, F.; Guarna, A. J. Chem. Soc., Perkin Trans. 1, 1979, 2793, and references therein.
8. (a) Huisgen, R. Angew. Chem., Int. Ed. Engl. 1963, 2, 565.
9. (b) Huisgen, R. Angew. Chem., Int. Ed. Engl. 1963, 2, 633.
10. (a) Dondoni, A.; Mangini, A.; Ghersetti, S. Tetrahedron Lett. 1966, 4789.
11. (b) Barbaro, G.; Battaglia, A.; Dondoni, A. J. Chem. Soc. (B), 1970, 588.
12. (a) Mallory, F. B.; Manatt, S. L.; Wood, C. S. J. Am. Chem. Soc. 1965, 87, 5433.
13. (b) Mallory, F. B.; Cammarata, A. J. Am. Chem. Soc. 1966, 88, 61.
14. (c) Hoffmann, R.; Gleiter, R.; Mallory, F. B. J. Am. Chem. Soc. 1970, 92, 2, 1460.
15. (a) Pasinszki, T.; Westwood, N. P. C. J. Phys. Chem. A 2001, 105, 1244.
16. (b) Pasinszki, T.; Westwood, N. P. C. J. Phys. Chem. A 1998, 102, 4939.
17. However, their computed activation barrier for decomposition of furoxan to acetonitrile oxides is 51.6 kcal/mol.6 This value is too high given the fact that thermolysis of furoxans can be used to generate nitrile oxides, which can participate in 1,3-dipolar cycloadditions with dipolarophiles. (a) Sheremetev, A. B.; Makhova, N. N.; Friedrichsen, W. Adv. Heterocycl. Chem. 2001, 78, 65.
18. (b) Curran, D. P.; Fenk, C. J. J. Am. Chem. Soc. 1985, 107, 5310.
19. (a) Himmel, H.-J.; Konrad, S.; Friedrichsen, W.; Rauhut, G. J. Phys. Chem. A 2003, 107, 6731.
20. (b) Stevens, J.; Schweizer, M.; Rauhut, G. J. Am. Chem. Soc. 2001, 123, 7326.
21. (a) Seminario, J. M.; Concha, M. C.; Politzer, P. J. Comput. Chem. 1992, 13, 177.
22. (b) Sedano, E.; Sarasola, C.; Ugalde, J. M.; Irazabalbeitia, I. X.; Guerrero, A. G. J. Phys. Chem. 1988, 92, 5094.
23. Studies of tautomerization of benzofuroxans have also attracted attention. For reviews, see: (a) Boulton, A. J.; Ghosh, P. B. Adv. Heterocycl. Chem. 1969, 10, 1.
24. (b) Gasco, A. J.; Boulton, A. J. Adv. Heterocycl. Chem. 1981, 29, 251.
25. (c) Katritzky, A. R.; Gordeev, M. F. Heterocycles 1993, 35, 483. For experimental researches on this field, see ref 5a and the following.
26. (d) Bulacinski, A. B.; Scriven, E. F. V.; Suschitzky, H. Tetrahedron Lett. 1975, 3577.
27. (e) Lin, S.-K. J. Photochem. Photobiol. A. Chem. 1988, 45, 243.
28. (f) Hacker, N. P. J. Org. Chem. 1991, 56, 5216.
29. (g) Gallos, J. K.; Lianis, P. S.; Rodios, N. A. J. Heterocycl. Chem. 1994, 31, 481.
30. For theoretical studies, see: (h) Ponder, M.; Fowler, J. E.; Schaefer, H. F. J., III Org. Chem. 1994, 59, 6431.
31. (i) Friedrichsen, W. J. J. Phys. Chem. 1994, 98, 12933.
32. (j) Rauhut, G. J. Comput. Chem. 1996, 17, 1848.
33. Houk, K. N.; González, J.; Li, Y. Acc. Chem. Res. 1995, 28, 81, and references therein.
34. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Zakrzewski, V. G.; Montgomery, J. A., Jr.; Stratmann, R. E.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.; Ochterski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Cioslowski, J.; Ortiz, J. V.; Baboul, A. G.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; Johnson, B. G.; Chen, W.; Wong, M. W.; Andres, J. L.; Head-Gordon, M.; Replogle, E. S.; Pople, J. A. Gaussian 98, revision A.7; Gaussian, Inc.: Pittsburgh, PA, 1998.
35. (a) Becke, A. D. J. Chem. Phys. 1993, 98, 5648.
36. (b) Lee C.; Yang, W.; Parr, R. G. Phys. Rev. B 1988, 37, 785.
37. Hehre, W. J.; Radom, L.; Schleyer, P. v. R.; Pople, J. A. Ab Initio Molecular Orbital Theory; Wiley: New York, 1986.
38. Tomasi, J.; Persico, M. Chem. Rev. 1994, 94, 2027.
39. (a) Yamaguchi, K.; Jensen, F.; Houk, K. N. Chem. Phys. Lett. 1988, 149, 537.
40. (b) Goldstein, E.; Beno, B.; Houk, K. N. J. Am. Chem. Soc. 1996, 118, 6036.
41. For both the dimerization transition states and the dinitrosoalkene intermediates, three letters are used to define the relative conformation. For example, for 2(ctc), the first and third c mean that the O3-N2-C1-C4 and O6-N5-C4-C1 are both in the s-cis conformations and the middle t means that two N=O groups are trans to each other (Figure 2). This nomenclature is the same as that of Rauhut8b for a convenient comparison of their RB3LYP calculations with the present study.
42. 0. Compared to TS1*, the singlet diradical TS1 is an earlier transition state with longer C1-C4 bond length (1.957 vs 1.875 Å). The computed structure of TS1* is given in the Supporting Information. TS1* has also been located previously by Pasinszki and Westwood.6
43. For discussions of iminoxy radicals, see: (a) Thomas, J. R. J. Am. Chem. Soc. 1964, 86, 1446.
44. (b) Bethoux, M.; Lemaire, H.; Rassat, A. Bull. Soc. Chim. Fr. 1964, 1985.
45. (c) Symons, M. C. R. J. Chem. Soc. 1965, 2276.
46. (d) Norman, R. O. C. J. Chem. Soc. B 1966, 86.
47. (e) Bordwell F. G.; Zhang, S. J. Am. Chem. Soc. 1995, 117, 4858.
48. For DFT studies, see: (f) Jaszewski, A. R.; Jezierska, J.; Jezierski, A. Chem. Phys. Lett. 2000, 319, 611.
49. (g) Kudoh, S.; Uechi, T.; Takayanagi, M.; Nakata, M.; Frei, H. Chem. Phys. Lett. 2000, 328, 283.
50. (h) Uechi, T.; Kudoh, S.; Takayanagi, M.; Nakata, M. J. Phys. Chem. A 2002, 106, 3365.
51. The computed structures of 2 are given in Figure S4 of the Supporting Information. The other conformers of singlet dinitrosoalkene reported by Rauhut and co-workers8b can only be located using restricted DFT instead of unrestricted DFT method. Rauhut found the most stable conformer of dinitrosoethene is in ttt conformation at the B3LYP/6-311++G** level. By using UB3LYP/6-311++G**, we found that the ctc conformer (singlet diradical) of dinitrosoethene is more stable in energy than the ttt conformer (closed-shell) by 9.9 kcal/mol (without ZPE and spin-projection corrections).
52. Other conformers of dinitrosoethene (except its ctc and ccc conformers) have been studied by Politzer and co-workers using the MP2/6-31G* method.9a We think MP2 is not appropriate to study the present system. At the (U)MP2/6-31G* level, the singlet diradical dinitrosoethene in ctc conformation is higher in energy than its closed-shell ttt conformer by 29.2 kcal/mol. This energy difference is questionable because we found that the restricted and unrestricted Hartree-Fock wave functions of these two conformers are not stable.22
53. Carsky, P.; Hubak, E. Theo. Chim. Acta 1991, 80, 407.
54. The triplet and singlet diradical states have not been corrected by spin projection method. Their computed structures are given in the Supporting Information.
55. 5c suggested nonplanar transition state for furoxan opening, which is the reverse step of 2(ccc) to furoxan 5, can also be located at the closed-shell RB3LYP/6-31G* level. However, this transition state is less stable than TS4 by 18.4 kcal/mol and therefore can be excluded for consideration.
56. 0‡(gas) + ΔΔ‡(sol) Here ΔΔG‡(sol) is the Gibbs energy of solvation computed by the PCM method.
57. 3CNO is also approximately 3.1 kcal/mol lower than that of para-chlorobenzonitrile, which has activation free energies 21.5-22.6 kcal/mol in various solvents,4 on the range of 18.4 and 19.5 kcal/mol.
58. For discussions of entropy overestimation in bimolecular reactions in aqueous solution, see: (a) Strajbl, M.; Sham, Y. Y.; Villa, J. V.; Chu, Y. Y.; Warshel, A. J. Phys. Chem. B 2000, 104, 4578.
59. (b) Hermans, J.; Wang, L. J. Am. Chem. Soc. 1997, 119, 2707.
60. (c) Amzel, L. M. Proteins 1997, 28, 144.
61. The diradical carbene mechanism of nitrile oxides has also been found in the intramolecular 1,3-dipolar ene reactions between nitrile oxides and alkenes, see: Yu, Z.-X.; Houk, K. N. J. Am. Chem. Soc. 2003, 125, 13825.