Trialkylphosphonium oxoborates as C(sp<sup>3</sup>)–H oxyanion holes and their application in catalytic chemoselective acetalization
作者:Vincent Ming-Yau Leung、Hong-Chai Fabio Wong、Chun-Man Pook、Ying-Lung Steve Tse、Ying-Yeung Yeung
DOI:10.1039/d3sc03081d
日期:——
borate counter anion in a TOB catalyst increases the availability of C(sp3)–H to interact with electron donor substrates. The catalytic protocol is applicable to a wide range of substrates in the acetalization reaction and provides excellent chemoselectivity in the acetalization over thioacetalization in the presence of alcohols and thiols, which is otherwise hard to achieve using typical acid catalysts
A Convenient Synthesis of 2-Tetrahydrofuranyl Ethers
作者:Rachid Baati、Alain Valleix、Charles Mioskowski、D. K. Barma、J. R. Falck
DOI:10.1021/ol991332f
日期:2000.2.1
[GRAPHICS]A wide spectrum of alcohols and phenols are readily transformed to the corresponding 2-tetrahydrofuranyl ethers in good to excellent yields using CrCl2 and CCl4 in THF under nearly neutral conditions at room temperature.
CuBr2-Promoted Tetrahydrofuranylation of Alcohols and 1,3-Dione
A method for the CuBr2-promoted tetrahydrofuranylation of alcohols and 1,3-dione has been developed. A variety of different alcohols were efficiently converted into the corresponding 2-tetrahydrofuran ethers in the presence of CuBr2. It is noteworthy that this protocol also successfully converted 1,3-diphenyl-1,3-dione into the corresponding 2-tetrahydrofuran derivative in good yield.
Visible Light-Induced α-C(sp<sup>3</sup>)–H Acetalization of Saturated Heterocycles Catalyzed by a Dimeric Gold Complex
作者:Xiaojia Si、Lumin Zhang、Zuozuo Wu、Matthias Rudolph、Abdullah M. Asiri、A. Stephen K. Hashmi
DOI:10.1021/acs.orglett.0c01924
日期:2020.8.7
situ-formed gold complex. The broad functional group compatibility and substrate scope indicate that our strategy is a promising way to synthesize acetal analogues. The method was successfully applied in late-stage modifications of bioactive molecules. Gramscale syntheses and mechanistic studies are also presented.