Facile metal free regioselective transfer hydrogenation of polarized olefins with ammonia borane
作者:Xianghua Yang、Thomas Fox、Heinz Berke
DOI:10.1039/c0cc03163a
日期:——
Transfer hydrogenation of polarized olefins bearing strongly electron-withdrawing groups on one side of the double bond was achieved with ammonia borane under mild conditions without using a catalyst. Mechanistic studies proved the character of the direct H transfers proceeding stepwise with a unique hydroboration intermediate and hydride before proton transfer.
Organocatalytic and Electrophilic Approach to Oxindoles with C3-Quaternary Stereocenters
作者:Jing Peng、Xin Huang、Hai-Lei Cui、Ying-Chun Chen
DOI:10.1021/ol101668z
日期:2010.10.1
A Lewis base-catalyzed asymmetricallylicalkylation of Morita−Baylis−Hillman carbonates derived from isatins has been investigated, which provides an electrophilic pathway to accessoxindoles bearing C3-quaternary stereocenters. Excellent diastereoselectivity and high enantioselectivity have been obtained in the vinylogous functionalization of α,α-dicyanoolefin nucleophiles, giving multifunctional