D-Prolyl-2-(trifluoromethylsulfonamidopropyl)pyrrolidine: An Organocatalyst for Asymmetric Michael Addition of Aldehydes to β-Nitroalkenes at Ambient Conditions.

Abstract

Four 2-(trifluoromethylsulfonamidoalkyl)pyrrolidines and their d-prolinamides were prepared and screened as organocatalysts for the Michael addition reaction of aldehydes with β-nitroalkenes at rt and without the use of additives. d-Prolyl-2-(trifluoromethylsulfonamidopropyl)pyrrolidine was found to be the best among the molecules studied, which yielded γ-nitro aldehydes in very high yields (up to 95%), with high diastereoselectivity (up to >99:1) and with up to 97% ee.