REACTIONS OF 1,2-DIMETHOXYTETRAMETHYLDISILANE WITH STYRENES: FORMATION OF A NEW TYPE OF SILACYCLOPENTANES HAVING PHENYL SUBSTITUENTS ON RING CARBONS

Article abstract of DOI:10.1016/0022-328X(83)80041-2

The reaction of 1,2-dimethoxytetramethyldisilane with styrene and α-methylstyrene in the presence of NaOMe catalyst in tetrahydrofuran (THF) gave the new silacyclopentanes 1,1-dimethyl-2,4-diphenyl-1-silacyclopentane (IIIa) and 1,1,2,4-tetramethyl-2,4-diphenyl-1-silacyclopentane (IIIb), respectively.These silacyclopentanes were found to exist as cis-trans mixtures.The use of sodium metal in place of NaOMe afforded similar results.Reactions of a polysilane mixture, MeO(SiMe2)nOMe (n <*> 3), with the styrenes also gave similar results.In some cases, polysilacycloalkanes such as 1,2,3-trisilacyclopentanes (IV) and 1,2,3,4-tetrasilacyclohexanes (V) were obtained as by-products.A mechanism for the formation of the silacyclopentanes and polysilacycloalkanes is presented.It was found that electron impact decomposition of silacyclopentanes IIIa and IIIb, trisilacycloalkane IV and tetrasilacycloalkane V gave molecular ions corresponding to the silacyclopropane, cyclotrisilane and cyclotetrasilane systems.