the preparation of trifluoromethyl N-acyl sulfilimines to the case of bromodifluoro- and dichlorofluoromethyl derivatives. Attempts to convert such N-acyl sulfilimines to free NH-sulfilimines failed. However, a strategy based on the reaction of their direct ditriflyl ketal precursor with amines allows the isolation of either original sulfilimino iminium salts using secondary amines or of free NH-sulfilimines