A new substitution reaction of acetylenic hydrogen with silyl radicals

Di-t-butyl peroxide-catalysed reaction of pentamethyldisilane with pentamethyldisilanylacetylene afforded cis- and trans-bis(pentamethyldisilanyl)ethylene and bis(pentamethyldislanyl)acetylene, the latter being formed by a novel hydrogen-abstraction process from an intermediate vinyl radical.