Highly Regio‑, Diastereo‑, and Enantioselective Mannich Reaction of Allylic Ketones and Cyclic Ketimines: Access to Chiral Benzosultam

An organocatalytic asymmetric Mannich reaction of allylic ketones with cyclic <i>N</i>-sulfonyl α-iminoester has been developed. By using a saccharide-derived chiral tertiary amino-thiourea catalyst, a range of allylic ketones and <i>N</i>-sulfonyl ketimines reacted smoothly to afford tetrasubstituted α-amino esters in high yields with good to excellent regio-, diastero-, and enantioselectivities