Diphenylprolinol silyl ether as a catalyst in an enantioselective, catalytic, tandem Michael/Henry reaction for the control of four stereocenters

Article abstract of DOI:10.1002/anie.200700909

(Chemical Equation Presented) 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.