Selective Oxidation of Benzylic Alcohols and TBDMS Ethers to Carbonyl Compounds with CrO<sub>3</sub>-H<sub>5</sub>IO<sub>6</sub>
作者:Mark L. Trudell、Suhong Zhang、Liang Xu
DOI:10.1055/s-2005-869975
日期:——
Benzyl alcohols and benzyl TBDMS ethers were efficiently oxidized to the corresponding carbonylcompounds in high yield with periodic acid catalyzed by CrO 3 at low temperature (-78 °C). The oxidation procedure was highlyfunctional group tolerant and very selective for the TBDMS group over the TBDPS group.
Oxidative Cleavage of Silyl Ethers by an Oxoammonium Salt
作者:Nicholas Leadbeater、Jacob Loman、Vincent Pistritto、Christopher Kelly
DOI:10.1055/s-0035-1561498
日期:——
A method for the oxidativecleavage of silyl ethers to their corresponding carbonyl species mediated by an oxoammonium salt is described. The resulting aldehydes and ketones are obtained under mild reaction conditions with no observed overoxidation. For robust substrates, heating to reflux temperatures significantly reduces the reaction time.
In the presence of a catalytic amount of Lewis acid, various carboxylic esters or S-phenyl carbothioates are prepared in excellent yields by the respective reactions of equimolar amounts of silyl carboxylates and alkyl silyl ethers or phenyl silyl sulfides with 4-trifluoromethylbenzoic anhydride.
Direct conversion of alcohol silyl ethers into the corresponding diphenylmethyl (DPM) ethers can be easily performed by the reaction with diphenylmethyl formate in the presence of a catalytic amount of trimethylsilyl trifluoromethanesulfonate. By the additional use of triethylsilane, tetrahydropyranylethers can be also converted into the corresponding DPM ethers.
An Efficient and Convenient Method for the Direct Conversion of Alkyl Silyl Ethers into the Corresponding Alkyl Ethers Catalyzed by Iron(III) Chloride
作者:Takeshi Oriyama、Katsuyuki Iwanami、Kentaro Yano
DOI:10.1055/s-2005-872120
日期:——
Various alcohol silyl ethers were readily and efficiently transformed into the corresponding alkyl ethers in high yields by the use of aldehydes combined with triethylsilane in the presence of a catalytic amount of iron(III) chloride.