Trimethylsilyl group, fluoride mediated

Magnus et al. have devised a route to ( )-lla-hydroxyestrone 3-methyl ether which, like the Saegusa synthesis (Scheme 20), makes use of fluoride mediated elimination of the trimethylsilyl group, but which is coupled with alternative methodology for in situ orthoquinodimethane generation (Scheme 21). ... 

In order for the 2-(trimethylsilyl)ethylthio unit to lose its protecting group upon treatment with the fluoride, the sulfur must be attached to an unsaturated carbon. Hence the fluoride mediated sulfur deprotection is feasible for 2-(trimethyl-silyl)ethylthio substituted (het)arenes, alkenes, alkynes, and acid derivatives such as carboxylic and selenothiophosphinic acid salts. In thiolate form, the substrates have value for the formation of self-assembled monolayers or as metal complexing agents. Simple addition of acid to the thiolate to give a stable thiol characterizes 2-(trimethylsilyl)ethanethiol as a simple M" (HS) equivalent that is only capable of a single substitution reaction. ... 

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