Diphenylprolinol Silyl Ethers as Efficient Organocatalysts for the Asymmetric Michael Reaction of Aldehydes and Nitroalkenes

The direct, catalytic, asymmetric Michael addition of aldehydes to nitroolefins in the presence of a chiral diphenylprolinol silyl ether organocatalyst is described (see scheme). The desired 1,4-addition products were obtained in nearly optically pure form in good yield with high syn diastereoselectivity. TMS=trimethylsilyl.