Selective Formation of β-<i>O</i>-Aryl Glycosides in the Absence of the C(2)-Ester Neighboring Group
作者:Matthew J. McKay、Benjamin D. Naab、Gregory J. Mercer、Hien M. Nguyen
DOI:10.1021/jo9002807
日期:2009.7.3
electron-withdrawing, and hindered phenols. The reaction is likely to proceed through a seven-membered ring intermediate, wherein the palladium catalyst coordinates to both C(1)-trichloroacetimidate nitrogen and C(2)-oxygen of the donor, blocking the α-face. As a result, the phenol nucleophile preferentially approaches to the top face of the activated donor, leading to formation of the β-O-aryl glycoside.
Stereoselective Aromatic<i>O</i>-Glycosylation of Glycosyl Chloride with Arylboronic Acid under an Air Atmosphere
作者:Jinsheng Lai、Shuqin Wu、Zhuoyi Zhou、Hui Liu、Yuanhong Tu、Qingju Zhang、Liming Wang
DOI:10.1021/acs.joc.3c00776
日期:2023.8.4
A novel exclusive β-selective O-aryl glycosylation was developed using glycosyl chloride and arylboronic acid with a palladium catalyst under an air atmosphere. The reaction was insensitive to moisture and characterized using readily available and bench-stable glycosyl chloride and arylboronic acid as substrates. A diverse range of substrate scopes, including various arylboronic acids and glycosyl
described using 2–20 mol% FeCl3/C as the catalyst and benzylated propargyl glycosides as the donors to reach yields up to 96% under mild condition. With an octatomic-ring intermediate at the α-face of FeCl3/C with alkyne of propargyl glycosides, a panel of aglycones comprising aliphatic, alicyclic, unsaturated alcohols, halogenated alcohols, and phenols with different substitution were examined successfully