Dityltin bis(triflate) is a mild Lewisacid which catalyzes clean Michael addition of enol silylethers. The new catalyst allows to employ various labile acceptors such as methyl vinyl ketone and 2-cyclopentenone which do not undergo smooth reaction with conventional Lewisacids. A variety of enol silylethers are also employable and thus 2-(trimethylsiloxy)propene, the simplest one in this class of