We describe a cerium‐catalyzed aerobic oxidative ringexpansion for the expedient construction of synthetically challenging macrolactones under visible‐light conditions. Cyanoanthracene has been employed as co‐catalyst to accelerate the turnover of the cerium cycle leading to a fast conversion within 20 min of irradiation. Taking advantage of the high efficiency and operationally simple conditions
A practical route from oxetane or thietane to γ‐(thio)butyrolactone via solvated‐proton‐assisted cobalt‐catalyzed carbonylative ring expansion under syngas atmosphere has been established. A wide variety of γ‐(thio)butyrolactones can be afforded in good to excellent yields. The versatility of this method has been well demonstrated in the synthesis of intermediates towards the natural product Arctigenin
Several substituted oxetanes were treated with lithium acetylides in the presence of borontrifluoride etherate to give f-hydroxyacetylenes. The reaction conditions were varied and several synthetic features of the present reaction were revealed.
Enantioselective Oxetane Ring Opening with Chloride: Unusual Use of Wet Molecular Sieves for the Controlled Release of HCl
作者:Wen Yang、Zhaobin Wang、Jianwei Sun
DOI:10.1002/anie.201601844
日期:2016.6.6
An unprecedented enantioselectiveoxetaneopening with chloride provides access to a range of highly functionalized three‐carbon building blocks. The excellent enantiocontrol is enabled not only by a new catalyst, but also by the unusualuse of wetmolecularsieves for the controlledrelease of HCl.