Isolable 1,1-Disubstituted Silole Dianion: a Homogeneous Two-Electron-Transfer Reducing Reagent

The 1,1-disubstituted silole dianion 2 has been isolated and characterized by single-crystal X-ray analysis for the first time. 2 can be used as a two-electron-transfer reducing reagent for the reduction of organic compounds and inorganic salts with regeneration of the corresponding neutral silole in nearly quantitative yields, indicating that it is an excellent reducing reagent. Reduction of (Mes)2SiCl2 with 2 selectively yielded the cyclotrisilane (Mes2Si)3 in high yield, which has not been isolated in pure form with the existing methods.