Thermal reactions of pivaloyl- and adamantoyl(tert-butylethynyl)bis(trimethylsilyl)silane with 2,3-dimethylbutadiene and diphenylacetylene

The thermal reactions of acylbis(silyl)silanes 1a and 1b gave the respective 2-sila-1-ene-3-ynes as the reactive intermediates. The 2-sila-1-ene-3-ynes thus formed reacted with the trapping agents such as 2,3-dimethylbutadiene to give the respective silyl-substituted cyclopentenes and ene-adducts. With diphenylacetylene, the silenes afforded silylcyclopropenes as the diastereomeric mixtures.