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

An unusual temperature effect on enantioselectivity was: found in a study o f Mn(salen)-catalyzed sulfimidation. The phenomenon was considered to be at tributable to the following reasons: the reaction of Mn(salen) and a nitren oid precursor (Arl-NTs) provides primarily an Mn-ArINTs adduct which underg oes sulfimidation and transformation to an Mn-nitrenoid species competitive ly; 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 don or ligand. (C) 2001 Elsevier Science Ltd. All rightsreserved.