Asymmetric Mannich-Type Reactions of Aldimines with a Chiral Acetate
作者:Susumu Saito、Keiko Hatanaka、Hisashi Yamamoto
DOI:10.1021/ol000099e
日期:2000.6.1
strongly on the use of o-alkoxy (or o-fluoro) aniline-derived aldimines which have been found to have a potential effect on the enolate addition. This scope was expanded to the asymmetric process using the chiral acetate. A Lewis acid additive has a complementary role in the pronounced activation of imine functionalities.
Catalyticenantioselective Mannich reactions of simple nonactivated esters proceeded using a chiral potassium strong base catalyst prepared from a chiral bisoxazoline and potassium hexamethyldisilazide. Alkyl acetates, alkyl propionates, and an alkyl butyrate were employed as the simple esters, and the desired reactions proceeded smoothly to afford Mannich products in good to high yields with high