Samarium Iodobinaphtholate: An Efficient Catalyst for Enantioselective Aza-Michael Additions of O-Benzylhydroxylamine to N-Alkenoyloxazolidinones

Samarium diiodide is an efficient catalyst for the aza-Michael addition of O-benzylhydroxylamine to alpha,beta-unsaturated N-acyloxazolidinones leading to mixtures of the Michael adduct and the product resulting from its amidation. Samarium iodobinaphtholate catalyzed reactions selectively afford the Michael adducts with enantiomeric excesses up to 88%. An isoinversion effect with temperature is observed with the highest enantiomeric excess at -40 degrees C.