Enantioselective organocatalytic conjugate addition of α-aminoketone to nitroolefins

The enantioselective organocatalytic conjugate addition of a-aminoketone to nitroolefins is reported

Enantioselective organocatalytic conjugate addition of aldehydes to nitrodienes

The asymmetric organocatalyzed Michael addition of aldehydes to alpha,beta-gamma,delta-unsaturated nitro compounds has been accomplished using only 5 mol % of (S)-diphenylprolinol silyl ether and 2 equiv of aldehyde in a mixture of ethanol and water (5% v/v). The Michael adducts were obtained in good yields, diastereoselectivities up to 94/6, and ee's up to 99%. This process provides synthetically useful compounds which can easily lead to more complex molecules, as exemplified with substituted tetrahydropyran or cyclohexene

Enantioselective one-pot organocatalytic michael addition/gold-catalyzed tandem acetalization/cyclization

A one-pot process consisting of a Michael addition to a nitroenyne and a subsequent acetalization/cyclization is reported (see scheme; TMS=trimethylsilyl), which results in the formation of nitro-substituted tetrahydrofuranyl ethers with high diastereo- and enantioselectivities. Organocatalysis and gold catalysis are compatible and complementary in a one-pot process