Silylation of silyl- and germylketenes containing bulky substituents at the silicon or germanium atom

Silylation of silyl- and germylketenes with trialkylsilyl triflates was stu died. Either the corresponding bis-organoelement-substituted ketenes or mix tures of these compounds with isomeric (silyloxy)silylacetylenes were forme d depending on the size of the substituents at the silicon or germanium ato m (both in ketenes and triflates) and on the nature of the heteroelement. T he resulting (silyloxy)silylacetylenes were isomerized into the correspondi ng bis-sitylketenes upon prolonged storage.