Striking reactivity of ylide-like germylene toward terminal alkynes: [4+2] cycloadditionversus C–H bond activation

Abstract

The isolable ylide-like N-heterocyclic germylene LGe: (2) {L = CH[(CCH₂)CMe][N(aryl)]₂, aryl = 2,6-ⁱPr₂C₆H₃} shows an unprecedented dual reactivity toward terminal alkynes: its reaction with acetylene leads via[4+2] cycloaddition to the novel intramolecular donor stabilised germylene 3, while conversion of phenylacetylene furnishes the analogous cycloadduct 4 along with a C–H bond activation product, the novel N-donor stabilised alkynyl germylene 5.