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)CH2 Cl2 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.

A photochemical (UVA) continuous flow process for the amination of thioethers and sulfoxides was performed with trichloroethoxysulfonyl azide in the presence of catalytic iron­(III) acetylacetonate. Aromatic and aliphatic sulfilimines and sulfoximines were produced in high yields and short reaction times. The reaction with chiral sulfoxides was stereospecific, producing enantioenriched sulfoximines in excellent yields.

Rhodium-Catalyzed Stereoselective Amination of Thioethers with N-Mesyloxycarbamates: DMAP and Bis(DMAP)CH 2Cl2 as Key Additives. -Chiral sulfilimines are prepared by rhodium-catalyzed intermolecular amination of thioethers with the readily available N-mesyloxycarbamate (I). DMAP and the related dimer BDC turn out to be crucial catalytic additives for improved diastereoselectivity. Cyclic voltametric measurements suggest a Rh(II)-Rh(III) complex as the catalytically active species. -(LEBEL*, H.; PIRAS, H.; BARTHOLOMEUES, J.; Angew. Chem., Int. Ed. 53 (2014) 28, 7300-7304, http://dx.