Organocatalytic diastereo- and enantioselective sulfa-Michael addition to α,β-disubstituted nitroalkenes

An effective asymmetric sulfa-Michael addition of various S-nucleophiles to a range of α,β-disubstituted nitroalkenes with bifunctional organocatalyst has been developed. The expected adducts could be obtained in high yields with reasonable diastereo- and enantioselectivities. This process provides an easy access to synthetically useful chiral 1,2-aminothiol derivatives bearing two vicinal stereocenters. Importantly, current work represents the first example about the catalytic asymmetric Michael addition of diverse S-nucleophiles except thioacetic acid to less reactive α,β-disubstituted nitroalkenes.