Enantioselective Synthesis ofβ-Amino Sulfones by aza-Michael Addition to Alkenyl Sulfones

Abstract

Regardless of whether SAMP or RAMBO (or their enantiomers RAMP or SAMBO) are used, the asymmetric synthesis of N-protected β-amino sulfones 4 by conjugate addition of a chiral nitrogen nucleophile (S)-1 (SAMP) or (R,R,R)-2 (RAMBO) to (E)-alkenyl sulfones 3 proceeds with high enantiomeric excesses. The title compounds are obtained after removal of the chiral auxiliary by reductive N−N bond cleavage.