Reductive deamination of α-amino carbonyl compounds by means of samarium iodide

Abstract

Reaction of α-amino carbonyl compounds with SmI₂ in THF–HMPA in the presence of a proton source afforded the deamination products, where the fragmentation occurred between the nitrogen and the carbon α to the carbonyl group.

References

1. P. Girard, J. L. Namy and H. B. Kagan, J. Am. Chem. Soc., 1980, 102, 2693.
2. Reviews: J. Inanaga, J. Org. Synth. Chem., 1989, 47, 200; J. A. Soderquist, Aldrichim. Acta, 1991, 24, 15; D. P. Curran, T. L. Fevig, C. P. Jasperse and M. J. Totleben, Synlett, 1992, 943; G. A. Molander, Chem. Rev., 1992, 92, 29; G. A. Molander and C. R. Harris, Chem. Rev., 1996, 96, 307; G. A. Molander and C. R. Harris, Tetrahedron, 1998, 54, 3321 and references cited therein.
3. G. A. Molander and P. J. Stengel, J. Org. Chem., 1995, 60, 6660; G. A. Molander and P. J. Sangel, Tetrahedron, 1997, 53, 8887; N. H. Kawahara and M. Goodman, Tetrahedron Lett., 1999, 40, 2271.
4. J. M. Aurrecoechea and A. Fernandez-Acebes, Tetrahedron Lett., 1993, 34, 549; J. M. Aurrecoechea and A. Fernandez-Acebes, Synlett, 1996, 39; A. R. Katritzky, M. Qi, D. Feng and D. A. Nichols, J. Org. Chem., 1997, 62, 4121.
5. H.-Y. Kang, A. N. Pae, Y. S. Cho, H. Y. Koh and B. Y. Chung, Chem. Commun., 1997, 821.
6. T. Honda, S. Yamane, K. Naito and K. and Y. Suzuki, Heterocycles, 1994, 37, 515; T. Honda, F. Ishikawa and S. Yamane, J. Chem. Soc., Chem. Commun., 1994, 499; T. Honda, S. Yamane, K. Naito and Y. Suzuki, Heterocycles, 1995, 40, 301; T. Honda, F. Ishikawa and S. Yamane, J. Chem. Soc., Perkin Trans. 1, 1996, 1125; T. Honda, S. Yamane, F. Ishikawa and M. Katoh, Tetrahedron, 1996, 37, 12177; T. Honda, M. Katoh and S. Yamane, J. Chem. Soc., Perkin Trans. 1, 1996, 2219; T. Honda and M. Katoh, Chem. Commun., 1997, 369.
7. The starting phenylalanine derivatives were prepared from the methyl ester by the known procedures; M. C. Allen, W. Fuhrer, B. Tuck, R. Wade and J. M. Wood, J. Med. Chem., 1989, 32, 1652 N,N-dimethyl derivative: T. Hayashi, M. Konishi, M. Fukushima, K. Kanehira, T. Hioki and M. Kumada, J. Org. Chem., 1983, 48, 2195 N-benzyl derivative: F. Effenberger, U. Burkard and J. Willfahrt, Liebigs Ann. Chem., 1986, 314 N,N-dibenzyl derivative: B. D. Gray and P. W. Jeffs, J. Chem. Soc., Chem. Commun., 1987, 1329 N-acetyl derivative: M. J. Burk, J. E. Feaster, E. H. Harlow and L. Richard, Tetrahedron: Asymmetry, 1991, 2, 569 N-Boc derivative: M. Sakaitani and Y. Ohfune, J. Org. Chem., 1990, 55, 870.
8. N-Benzylproline methyl ester was prepared from methyl prolinate: V. Ferey, P. Vedrenne, L. Toupet, T. L. Gall and C. Mioskowski, J. Org. Chem., 1996, 61, 7244; isopropyl 4-tert-butyldimethylsiloxyprolinate was prepared by silylation of the corresponding ester, which on N-benzylation with BnBr and NaH gave the N-benzyl derivative..
9. N-Substituted pipecolinates were prepared from ethyl pipecolinate by alkylation with the suitable alkyl halide and Prⁱ₂NEt or by acetylation with Ac₂O.
10. 2-Acetyl-N-alkylpiperidine derivatives were preparod from ethyl pipecolinate via four steps involving N-alkylation with alkyl halide, hydrolysis of the ester, conversion of the acid to the Weinrebs amide (S. Nahm and S. M. Weinreb, Tetrahedron Lett, 1981, 22, 3815), and treatment of the amide with MeMgBrthe N-acetyl compound was derived from the N-benzyl derivative by reductive debenzylation over Pd/C in the presence of Ac₂O; the N-Boc derivative was prepared according to the known procedure: S. Aoyagi, T-C. Wang and C. Kibayashi, J. Am. Chem. Soc, 1993, 115, 11393.
11. J. Inanaga, M. Ishikawa and M. Yamaguchi, Chem. Lett., 1987, 1485.