The Preparation and Properties of (Hydroxyorgano)-silanes and Related Compounds

Abstract

Preparation and Properties of (Hydroxyorgano) -silanes 1003 trolled Glas-Col mantle. Commercial "98% plus" cresols (6) D.

Synthesis and characterization of new bi-functional monomers based on germarylene or silarylene units: 4,4′-(R1R2-silylene)bis(phenyl chloroformates) and 4,4′-(R1R2-germylene)bis(phenyl chloroformates)

“…Using this procedure, the preparation of bis(p-hydroxyphenyl)dimethyl-silane and germane [3 -7], bis(p-hydroxyphenyl)diphenyl-silane and -germane [3,5], bis(p-hydroxyphenyl)diethyl-silane [6,7] and germane [8], bis(p-hydroxyphenyl)di n propylsilane [6,7], bis(p-hydroxyphenyl)di n buthylgermane [8] and bis(p-hydroxyphenyl)methylphenylsilane [9] has been reported with good yield. Some structural variations upon these compounds have also been found following this route, for example, bis(o-hydroxyphenyl)diphenylsilane [10] and bis(2-methyl-p-hydroxyphenyl) dimethylsilane [11].…”

Improved Synthesis of the Benzyne Precursor 2-(Trimethylsilyl)phenyl Trifluoromethanesulfonate

“…Herein, we report the full experimental details for a modified synthetic sequence that eliminates the use of organolithium reagents affording 1 in excellent yield with a significantly shorter overall reaction time than previously reported syntheses. In the first modification, the reaction time for the first step involving conversion of 3 to 4 could be reduced from several days 6 to five minutes by treatment of 2-chlorophenol 3 with hexamethyldisilazane (HMDS) and freshly prepared NaHSO 4 -SiO 2 (Scheme 2). 7,8 This procedure facilitates the rapid transformation of 3 to 4 at room temperature and eliminates the vigorous emission of hydrogen chloride gas as observed with the previous silylation method.…”

An Efficient Procedure for the Synthesis ofortho-Trialkylsilylaryl Triflates: Easy Access to Precursors of Functionalized Arynes

“…The use of 2-trimethylsilylphenyl triflate (2a) 5 as a benzyne precursor was first reported in 1983 by Himeshima et al, 4a who obtained 2a in 86% yield from (o-trimethylsilylphenoxy)trimethylsilane (preparation of the latter in two steps from an o-halophenol had been described previously 6 ). Our modified procedure for the synthesis of 2a involves quantitative silylation of 2-bromophenol (1a) by treatment with hexamethyldisilazane (HMDS) at 80 °C (with or without solvent), 7 and reaction of a solution of the crude product in THF with one equivalent of BuLi at -100°C…”

“…The mechanism of the process, shown in Scheme 2, involves conversion of (o-bromophenoxy)trimethylsilane (3) to the carbanion 4 by metal-halogen exchange, migration of the trimethylsilyl group from oxygen to carbon, and trapping of the resulting lithium phenoxide 5 with triflic anhydride. 6,8,9 Careful control of the reaction temperature is crucial for the success of this transformation, as a higher temperature favors nucleophilic attack by the base on the silicon atom of 3 and also promotes polymerization of THF in the presence of trace amounts of triflic acid.…”