Efficient direct asymmetric vinylogous Michael addition reactions of gamma-butenolides to chalcones catalyzed by vicinal primary-diamine salts

Abstract

The first direct organocatalytic asymmetric vinylogous Michael addition reactions of gamma-butenolides to chalcones have been developed by using chiral 1,2-diaminocyclohexane as a novel organocatalyst via a di-iminium transition state to provide syn-Michael products with good yields, high diastereoselectivities and enantioselectivities (up to 78% yield, >99 : 1 dr and 96% ee).