Non-catalyzed addition reactions of Cl3SiSiCl3 with 1,2-diketones, 1,2-quinones and with a 1,4-quinone

The first uncatalyzed reactions of a disilane with 1,2-diketones, 1,2-quinones and with a 1,4-quinone are reported. Thus, Si2Cl6 reacts under mild conditions with such substrates to give bis-trichlorosiloxy addition compounds. The structure of the corresponding addition compound of benzyl, namely, cis-PhC(OSiCl3)C(OSiCl3)Ph was structured by X-ray diffraction analysis. Evidence for the intermediacy of five-coordinate species in these reactions is discussed. A reaction of Si2Cl6 with LiNMeC(O)Et aimed at making a hypercoordinate silicon complex led to the disproportionation product cis-Cl2Si[NMeC(O)Et]2 (whose structure was also determined by X-ray diffraction analysis) in which the amide ligands chelate the silicon via the nitrogen and oxygen to form five-membered rings whose bond lengths suggest substantial electron delocalization.