Organosilicon chemistry. Part XIX. Reactions of 1,1,3,3-tetramethyl- and 1,3-dimethyl-1,3-diphenyl-1,3-disilacyclobutane with chlorosilanes in the presence of hexachlorophatinic(IV) acid, tin(IV) chloride, trimethylsilanol, and triphenylsilanol

Abstract

1,1,3,3-Tetramethyl-1,3-disilacyclobutane, (I), reacts with trichlorosilane or dichloro(methyl)silane in the presence of hexachloroplatinic(IV) acid to give the chlorine-exchange adducts, Me₂SiCl·CH₂·SiMe₂·CH₂·SiHCl₂(80%) or Me₂SiCl·CH₂·SiMe₂·CH₂·SiMeHCl (61%); in the latter reaction the hydrogen-exchange adduct, Me₂SiH·CH₂·SiMe₂·CH₂·SiMeCl₂(5%). is also formed. A comparable reaction of 1.3-dimethyl-1.3-diphenyl-1,3-disilacyclobutane, (II), with trichlorosilane gives mainly polymeric material together with the chlorine-exchange adduct (10%). Both silacyclobutanes react with tin(IV) chloride in the absence of catalyst or with trimethylsilanol to afford ring-opened 1 :1 adducts in high yield. Compound (I) also reacts with triphenylsilanol to afford hexaphenyldisiloxane and 1,1,3,3-tetramethyl-1,3-bis(trimethylsilylmethyl)disiloxane (87%); (II) does not react under comparable conditions.