F-Butyldimethylsilyl trifluoromethanesulfonate

Depending on the experimental conditions, reaction of (1) with f-butyldimethylsilyl trifluoromethanesulfonate leads either to the expected /3-trimethysilyl enol ether (11), or to its isomer (12) formed by a 1,3-migration of the trimethylsilyl group from the oxygen atom to the carbon atom (1 13). Reaction with f-butyldimethylchlorosilane always gives (12). Trimethylsilyl enol ether (11) is easily hydrolyzed to 2-(t-butyldimethylsilyl)-acetaldehyde (14) (eq 7). ... 

Di-f-butylmethylsilyl trifluoromethanesulfonate, r-Bu2MeSiOTf. The triflate is obtained as an oil, b.p. 63-65°/15 mm, by reaction of f-Bu2MeSiH with triflic acid (95% yield). The reagent is used to prepare DTBMS esters and ethers, which are more stable than the t-butyldimethylsilyl counterparts. Thus the esters are not reduced by lithium t-butyldiisobutylaluminum hydride (10, 239-240) or hydrolyzed by acid, but are cleaved by BU4NF.1... 

SILYLATION Bis(trimethylsilyl)urea. t-Butyldimethylchlorosilane. t-Butyldimethylsilyl trifluoromethanesulfonate. Chlorotrimethylsilane. Dimethyl(2,4,6-tri-f-butylphenoxy)chlorosilane. Ethyl trimethylsilylacctate. Ketene t-butyldimethylsilyl methyl acetal. N-Methyl-N-(/-... 

Reaction with Nucleophiles. TBDMSCl is the reagent of choice for the preparation of other TBDMS-containing reagents. For example, f-butyldimethylsilyl cyanide may be prepared by the reaction of TBDMSCl and potassium cyanide in acetonitrile containing a catalytic amount of zinc iodide. TBDMSCN has also been prepared by treatment of TBDMSCl with KCN and 18-crown-6 in CH2CI2 at reflux and by treatment of TBDMSCl with lithium cyanide prepared in situ. i-butyldimethylsilyl trifluoromethanesulfonate is prepared by treatment of TBDMSCl with trifluoromethanesulfonic acid at 60 °C. Other nucleophiles, such as thiolates, also react with TBDMSCl. f-butyldimethylsilyl iodide was prepared by treatment of TBDMSCl with sodium iodide in acetonitrile. In contrast to THF cleavage reactions using TMSI, the more stable TBDMS-protected primary alcohol may be isolated from the reaction in eq 12. 

Related Reagents. f-Butyldimethylchlorosilane triethylsi-lyl trifluoromethanesulfonate trimethylsilyl trifluoromethane-sulfonate f-butyldimethylsilyl iodide A -f-(butyldimethylsilyl)-W-methyltrifluoroacetamide triisopropylsilyl trifluoromethanesulfonate. 

Related Reagents. f-Butyldimethylsilyl Trifluoromethane-sulfonate Chlorotrimethylsilane lodotrimethylsilane Triethyl-silyl Trifluoromethanesulfonate. 

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