Silylation agents

The ease with which alcohols and phenols can be converted to silyl ethers as compared with alkyl ethers has made silylation, generally, the derivatization method of choice for hydroxy compounds. Furthermore, intermolecular attractive forces involving trialkylsilyl (R3Si-) groups are relatively small the conversion of a typical alcohol to its trimethylsilyl (TMS) ether results in an increase of 72 mass units per molecule with only slight decrease in volatility. 

The search for a compound RjSiX strongly electrophilic (but yielding a nonacidic HX) led to the silyl iminol ethers, the prototype of which is A, 0-bis-trimethylsilyla-cetamide (BSA) [186]. Reactions with proton donors such as alcohols are thermodynamically driven by the formation of the carbonyl group of the corresponding amide  

BSA is reported to react practically quantitatively, not only with alcohols, 

Where strength of silylating agent is the most important consideration, trimethyl-silylimidazole (TSIM) has been the reagent of choice. Another reagent which takes advantage of a nucleophilic group s ready displacement without formation of a 

Strong acid, TSIM is capable of derivatizing most O-H bonds (but not N-H bonds), including such inaccessible ones as those on C-17 of pregnane derivatives [189]. In contrast to MSTFA, it does not affect enolizable ketones [191]. 

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SAN copolymers in [ACRYLONITRILE POLYTffiRS - SURVEY AND SAN (STYRENE-ACRYLONITRME CO-POLYTffiRS)] (Vol 1) -silylating agents for [SILICON COMPOUNDS - SILYLATING AGENTS] (Vol 22)... 

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