Organocatalytic asymmetric synthesis of 1,2,4-trisubstituted azetidines by reductive cyclization of Aza-Michael adducts of enones

Article abstract of DOI:10.1055/s-0031-1290954

An efficient and highly enantioselective organocatalytic aza-Michael addition of N-substituted phosphoramidates to enones generates aza-Michael adducts which undergo intramolecular reductive cyclization with (R)-alpine borane to afford 1,2,4-trisubstituted azetidines in a one-pot procedure. These optically active products are obtained in good to high yields (67-93%) with excellent stereocontrol (78-96% ee) from a vast variety of enones. Georg Thieme Verlag Stuttgart · New York.