Prolinal dithioacetals: Highly efficient organocatalysts for the direct nitro-Michael additions in both organic and aqueous media

Some novel prolinal dithioacetal derivatives have been synthesized and applied as the organocatalysts for the direct Michael addition of ketones and aldehydes to nitroalkenes. High enantioselectivities and diastereoselectivities have been obtained in both organic and aqueous media (dichloromethane, water, or brine).