Organosilicon chemistry. Part XVIII. Some reactions of 1,3-dimethyl-1,3-diphenyl-, 1,1,3,3-tetraphenyl-, and 1,1-dimethyl-3,3-diphenyl-1,3-disilacyclobutane

Abstract

Ring-opening of 1,3-dimethyl-1,3-diphenyl- and 1,1,3,3-tetraphenyl-1,3-disilacyclobutane takes place on treatment with halogens, hydrogen halides, lithium aluminium hydride, sodium hydroxide, or sulphuric acid, but the reactions with halogens and hydrogen halides are complicated by silicon-phenyl bond scission. 1,1 -Dimethyl-3,3-diphenyl-1,3-disilacyclobutane is conveniently prepared by reaction of an equimolar mixture of the silanes Me₂SiCl·CH₂Cl and Ph₂SiCl·CH₂Cl in tetrahydrofuran with magnesium. It reacts with hydroxide, methoxide, ethoxide, hydride ion, hydrogen chloride, or hydrogen bromide to give major products arising via SiMe₂–CH₂ bond scission, but in contrast it reacts with chlorine or bromine to give major products arising via SiPh₂–CH₂ bond scission.