Lewis Acid Catalyzed Electrophilic Aminomethyloxygenative Cyclization of Alkynols with <i>N</i>,<i>O</i>-Aminals
作者:Anrong Chen、Houjian Yu、Jiaqi Yan、Hanmin Huang
DOI:10.1021/acs.orglett.9b04630
日期:2020.1.17
Lewis acid enables the electrophilic carbooxygenative cyclization of alkynols with N,O-aminals. The new process proceeds efficiently under very mild conditions via a pathway that is opposite to classical carbo-metalation. These reactions exhibit broad substrate generality and functional group compatibility, leading to a wide variety of 5-8-membered oxacycles bearing diverse functional groups. The cyclization
Alcoholysis of Epoxides Catalyzed by Tetracyanoethylene and Dicyanoketene Acetals
作者:Yukio Masaki、Tsuyoshi Miura、Masahito Ochiai
DOI:10.1246/bcsj.69.195
日期:1996.1
A typical π-acid tetracyanoethylene and capto-dative olefin dicyanoketeneacetals were found to catalyze stereospecific alcoholysis of epoxides at the ambient temperature to 50 °C in good yields. Mildness and significant chemoselectivity of the catalysts were demonstrated by intactness of tetrahydropyranyl ether and ethylene acetal groups. A novel regioselectivity associated with anchimeric assistance