RADICAL-INITIATED HYDROSILYLATION-CYCLIZATION REACTIONS OF BIS(VINYLDIMETHYLDIMETHYLSILYL) COMPOUNDS, CH2=CH(CH3)(2)SIXSI(CH3)(2)CH=CH2 (X=O, CH2, NH, NCH3, NSI(CH3)(3)

The di-tert-butyl peroxide-initiated reactions of triethyl- and tri-n-propylsilane with bis(vinyldimethylsilyl) compounds, CH2=CH(CH3)(2)SiXSi(CH3)(2)CH=CH2 (X = O, CH2, NH, NCH3 and NSiMe(3)) resulted in hydrosilylation-cyclization to give mixtures of trialkylsilylmethyl-substituted disilacyclohexanes and trialkylsilylmethyl-substituted disilacyclopentanes. The ratio of six-membered to five-membered ring products obtained is dependent on the linking group X and decreased in the order X=O > CH2 > NH > NCH3. For X=NSiMe(3) only a mixture of the cis and trans isomers of the five-membered ring product was obtained.