An enantioselective Baylis–Hillman reaction catalyzed by chiral phosphines under atmospheric pressure

Abstract

2,2’-Bis(diphenylphosphino)-1,1’-binaphthyl (BINAP) catalyzes the enantioselective Baylis–Hillman reaction between pyrimidine- 5-carbaldehydes and acrylates to provide chiral α-methylene β-hydroxy esters in up to 44% ee under atmospheric pressure.

References

1. Reviews, see: D. Basavaiah, P. D. Rao and R. S. Hyma, Tetrahedron, 1996, 52, 8001; S. E. Drewes and G. H. P. Roos, ibid., 1988, 44, 4653; H. M. R. Hoffmann and J. Rabe, Angew. Chem., Int. Ed. Engl., 1985, 24, 4653.
2. For example, see: I. E. Marcó, P. R. Giles, Z. Janousek, H. J. Hindley, J.-P. Declercq, B. Tinant, J. F.-Dupont and J. S. Svensen, Recl. Trav. Chim. Pays-Bas, 1995, 114, 239; M. Bailey, I. E. Marcó and W. D. Ollis, Tetrahedron Lett., 1991, 32, 2687; J. M. Brown, Angew. Chem., Int. Ed. Engl., 1987, 26, 190.
3. T. Oishi, H. Oguri and M. Hirama, Tetrahedron: Asymmetry, 1995, 6, 1241.
4. I. E. Marcó, P. R. Giles and H. J. Hindley, Tetrahedron, 1997, 53, 1015.
5. For diastereoselective Baylis–Hillman reactions, see: L. J. Brzezinski, S. Rafel and J. W. Leathy, J. Am. Chem. Soc., 1997, 119, 4317 and ref. 1.
6. For the use of trialkylphosphines in non-asymmetric Baylis–Hillman reaction, see: S. Rafel and J. W. Leathy, J. Org. Chem., 1997, 62, 1521.
7. Bis(diphenylphosphino)butane (CHIRAPHOS) was utilized as a catalyst in the reaction of an N-tosyl imine with methyl acrylate but no asymmetric induction was reported to be observed: S. Bertenshaw and M. Kahn, Tetrahedron Lett., 1989, 30, 2731 Intramolecular enantioselective reaction using chiral phosphine was reported (14% ee): F. Roth, P. Crygak and G. Fráter, Tetrahedron Lett., 1992, 33, 1045.
8. For early examples of the use of BINAP in enantioselective hydrogenation: R. Noyori and H. Takaya, Acc. Chem. Res., 1990, 23, 345.