A New Type of Chiral Cyclic Sulfinamide–Olefin Ligands for Rhodium‐Catalyzed Asymmetric Addition

Abstract

A new type of chiral cyclic sulfinamide–olefin ligands, N‐allylic 2,3‐dihydro‐1,2‐benzoisothiazole 1‐oxides, with 2,3‐dihydro‐1,2‐benzoisothiazole 1‐oxide as a unique chiral skeleton, is developed for the highly enantioselective rhodium‐catalyzed asymmetric 1,4‐addition of α,β‐unsaturated cyclic carbonyl compounds and the 1,2‐addition of benzil. Both enantiomers of the chiral cyclic sulfinamide–olefin ligand with 99 % ee were easily prepared from inexpensive and commercially available starting materials and were directly used in asymmetric catalysis, and thus, both enantiomers of the addition products could be obtained in high yields (up to 98 %) with excellent enantioselectivities (up to 98 % ee).