Organosilicon chemistry. Part XX. Further reactions of 1,1,3,3-tetra-methyl-, 1,3-dimethyl-1,3-diphenyl-, and 1,1,3,3-tetraphenyl-1,3-disilacyclobutane

Abstract

1,1,3,3-Tetramethyl-1,3-disilacyclobutane, (I), reacts with iodine monochloride or sodium benzenethiolate in benzenethiol to give reasonable yields of ring-opened 1 :1 adducts, while reaction with bromobis(trifluoromethyl)-amine affords a mixture of perfluoro-2-azapropene and 1-bromo-4-fluoro-2,2.4-trimethyl-2,4-disilapentane via decomposition of the initially formed 1:1 adduct. 1,3-Dimethyl-1,3-diphenyl-1,3-disilacyclobutane, (II), reacts similarly with sodium benzenethiolate in benzenethiol and the bromoamine, but reaction with iodine mono-chloride affords mainly polymeric material. The reaction of sulphur trioxide with compound (II) results in insertion into a ring Si–CH₂ bond and a Si–Ph bond in the ratio 9 : 90, while reaction with 1,1,3,3-tetraphenyl-1,3-disila-cyclobutane, (III), gives the Si–Ph insertion product exclusively. Both the phenyl-substituted disilacyclobutanes react with mercury(II) acetate in ethanol to give ring-opened products of the type AcO·Hg·CH₂·[graphic omitted]i·CH₂·[graphic omitted]i·OEt in high yield.