Rhodium‐Catalyzed Stereoselective Amination of Thioethers with N ‐Mesyloxycarbamates: DMAP and Bis(DMAP)CH 2 Cl 2 as Key Additives

A stereoselective Rh‐catalyzed intermolecular amination 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)CH 2 Cl 2 proved pivotal in achieving high selectivity. The X‐ray crystal structure of the (DMAP) 2 ⋅[Rh 2 {( S )‐nttl} 4 ] complex was obtained and mechanistic studies suggested a Rh II ‐Rh III complex as the catalytically active species.