Rhodium-Catalyzed Stereoselective Animation of Thioethers with N-Mesyloxycarbamates: DMAP and Bis(DMAP)CH2Cl2 as Key Additives

摘要

A stereoselective Rh-catalyzed intermolecular ami-nation of thioethers using a readily available chiral N-mesyloxycarbamate to produce sulfilimines in excellent yields and diastereomeric ratio is described. A catalytic mixture of 4-dimethylaminopyridine (DMAP) and bis-(DMAP)CH2Cl2 proved pivotal in achieving high selectivity. The X-ray crystal structure of the (DMAP)2·[Rh2{(S)-nttl}4] complex was obtained and mechanistic studies suggested a Rh~(II)-Rh~(III) complex as the catalytically active species.