Tandem Si-Si and Si-H Activation of 1,1,2,2-Tetramethyldisilane by Gold Nanoparticles in Its Reaction with Alkynes: Synthesis of Substituted 1,4-Disila-2,5-cyclohexadienes

The Au/TiO2-catalyzed reaction between 1,1,2,2-tetramethyldisilane and terminal alkynes yields substituted 1,4-disila-2,5-cyclohexadienes (1,1,4,4-tetramethyl-1,4-dihydro-1,4-disilines) in moderate to good yields. The reaction proceeds via initial SiSi activation of disilane by gold nanoparticles to form with alkynes isolable cis-1,2-disilyl adducts (cis-1,2-bis(dimethylsilyl)ethenes), which, under the reaction conditions, undergo a Au-catalyzed dehydrogenative cycloaddition to a second alkyne molecule, forming the final cycloadducts.