Aerobic epoxidation of tertiary allylic alcohols remains a significant challenge. Reported here is an efficient and highly chemoselective copper‐catalyzed epoxidation and semipinacol rearrangement reaction of tertiary allylic alcohols with molecular oxygen. The solvent 1,4‐dioxane activates dioxygen, thereby precluding the addition of a sacrificial reductant.
Unexpected Copper-Catalyzed Aerobic Oxidative Cleavage of C(sp<sup>3</sup>)–C(sp<sup>3</sup>) Bond of Glycol Ethers
作者:Zhong-Quan Liu、Lixing Zhao、Xiaojie Shang、Zili Cui
DOI:10.1021/ol301220s
日期:2012.6.15
An unexpected Cu-catalyzed oxidative cleavage of the C(sp(3))-C(sp(3)) bond in glycol ethers by using air or molecular oxygen as the terminal stoichiometric oxidant is demonstrated. As a result, the corresponding alpha-acyloxy ethers and formates of 1,2-ethanediol are formed by direct coupling of carboxylic acids and aldehydes with glycol ethers under the reaction conditions. This method represents the first example of Cu-catalyzed aerobic cleavage of saturated C-C bond in ethers.