Asymmetric reactions of axially chiral amides: use of removable ortho-substituents in radical cyclizations of o-iodoacrylanilides and N-allyl-N-o-iodoacrylamides
作者:Marc Petit、Steven J. Geib、Dennis P. Curran
DOI:10.1016/j.tet.2004.05.116
日期:2004.8
Radical cyclizations of enantiomerically enriched o-iodoacrylanilides and N-allyl-o-iodoanilides bearing a removable ortho-substituent such as trimethylsilyl or bromine provide oxindoles and indoles in good yields and with good to excellent levels of chirality transfer from the N–Ar axis to the new stereocenter. Transition state models for the chirality transfer are suggested. Chemoselectivity of the
带有可移动邻位取代基(如三甲基甲硅烷基或溴)的对映异构体富集的邻碘丙烯酰苯胺和N-烯丙基-邻碘苯胺的自由基环化可提供高收率的羟吲哚和吲哚,并具有良好的手性从N-Ar轴转移至N-Ar新的立体中心。建议用于手性转移的过渡态模型。在2-碘-6-溴的情况下有利于碘的自由基环化反应的化学选择性Ñ -allylacrylamides已开发用于通过5-一锅序列合成手性pyrroloquinolinones的外型和6-内的环化反应。