A high yielding synthesis of optically active 3,5-disubstituted salicylidene β-amino alcohols (6) is described. The catalytic use of D or L-N-(3-phenyl-5-nitrosalicylidene)valinol in enantioselective sulfoxidation (H2O2 / VO(acac)2) gives up to 95% e.e. Asymmetric conjugate addition of thiophenol to 2-cyclohexen-1-one catalysed by Ti(OPr-i)4 and 6 leads to maximum 31% e.e. in the product.
For recent applications, see: enantioselective reaction of diketene with aldehydes: (a) HayashiM., TanakaK., and OguniN., Tetrahedron: Asymmetry, 1995, 6, 1833–1836.
2.
HayashiM., KanedaH., and OguniN., Tetrahedron: Asymmetry, 1995, 6, 2511–2516; trimethylsilylcyanation: (c) Y. Jiang, X. Zhou, W. Hu, L. Wu, and A. Mi, Tetrahedron: Asymmetry, 1995, 6, 405–408.
3.
JiangY., ZhouX., HuW., LiZ., and MiA., Tetrahedron: Asymmetry, 1995, 6, 2915–2916; asymmetric sulfoxidation:3,4 and (e) A.H. Vetter and A. Berkessel, Tetrahedron Lett., 1998, 39, 1741–1744; enantioselective arylation of epoxides: (f) N. Oguni, Y. Miyagi and K. Itoh, Tetrahedron Lett., 1998, 39, 9023–9026.
