At the edge of stability - Preparation of methyl-substituted arylsilanetriols and investigation of their condensation behavior

Abstract

A series of arylsilanetriols [Aryl-Si(OH)3, Aryl = 2,6-dimethylphenyl, 2,4,6-trimethylphenyl 2,3,5,6-tetramethylphenyl] with two, three, and four methyl groups at the phenyl ring was prepared from the corresponding trichlorosilanes. While the durene substituted silanetriol was formed exclusively, the other silanetriols were obtained together with their primary condensation products in a constant ratio 4:1. For the mesityl-substituted derivative an alternative synthetic access via the trialkoxysilane was explored, which turned out to be inferior in terms of product yield. Despite their increased steric size the methylated phenylsilanetriols are prone to condensation in solution as well in the solid state, although the dimerization rate is reduced compared to the unsubstituted phenylsilanetriol. All compounds were characterized with 29Si, 1H, 13C NMR, HRMS elemental analysis, IR spectroscopy, and in some cases single X-ray crystallography. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.