Diphenylprolinol Silyl Ether as a Catalyst in an Enantioselective, Catalytic, Tandem Michael/Henry Reaction for the Control of Four Stereocenters

Abstract

A choice of three: The tandem Michael/Henry reaction of a nitroalkene and pentane-1,5-dial (generated in situ) proceeded efficiently when diphenylprolinol silyl ether was used as an organocatalyst to afford substituted nitrocyclohexanecarbaldehydes with high diastereo- and enantioselectivity (see scheme; TMS: trimethylsilyl). Isomerization under basic or acidic conditions diastereoselectively converts the product into two stereoisomers, without compromising the enantioselectivity.