The cis-insertion of diphenylacetylene into an exo-polyhedral boron–hydrogen bond of a molybdenacarbaborane cage

Abstract

The η²(4e)-alkyne bis(trimethylphosphite) substituted complexes [closo-3-(η²-alkyne)-3,3-{P(OMe)₃}₂ 31,2-MoC₂B₉H₁₁] react with alkynes to form either monophosphite bis(alkyne) or mixed alkyne complexes [closo-3,3-(η²-alkyne)(η²-alkyne)-3-{P(OMe)₃}-3,1,2-MoC₂B₉H₁₁]; however, an attempt to extend the reaction to the bis(diphenylacetylene) system resulted in a novel cis-insertion of the alkyne into an exo-polyhedral B–H bond, which is explained by a bimetallic reaction pathway.