Mn(salen)-catalyzed sulfimidation: what are the real active species in sulfimidation?

An unusual temperature effect on enantioselectivity was: found in a study of Mn(salen)-catalyzed sulfimidation. The phenomenon was considered to be attributable to the following reasons: the reaction of Mn(salen) and a nitrenoid precursor (Arl-NTs) provides primarily an Mn-ArINTs adduct which undergoes sulfimidation and transformation to an Mn-nitrenoid species competitively; however, the rates of sulfimidation by the Mn ArINTs adduct and the Mn-nitrenoid species and of the transformation are dependent on the structure of the catalyst, the nature of ArI-NTs and the presence or absence of a donor ligand. (C) 2001 Elsevier Science Ltd. All rightsreserved.