A Mechanistic Study on the Catalytic, Asymmetric α-Bromination of Acid Chlorides
作者:Cajetan Dogo-Isonagie、Tefsit Bekele、Stefan France、Jamison Wolfer、Anthony Weatherwax、Andrew E. Taggi、Daniel H. Paull、Travis Dudding、Thomas Lectka
DOI:10.1002/ejoc.200600819
日期:2007.3
The mechanism of the catalytic, asymmetricα-bromination of acidchlorides is probed through a series of crossover experiments, ion-pairing tests, and kinetic resolution studies to shed light on the factors that contribute to, and limit the production of, optically-active α-bromo esters. In order to understand better the observed sense of induction, as well as the high degree of enantiomeric excess
Scalable Methodology for the Catalytic, Asymmetric α-Bromination of Acid Chlorides
作者:Cajetan Dogo-Isonagie、Tefsit Bekele、Stefan France、Jamison Wolfer、Anthony Weatherwax、Andrew E. Taggi、Thomas Lectka
DOI:10.1021/jo061522l
日期:2006.11.1
The optimization of a practical, catalytic, asymmetric process for the α-bromination of acidchlorides to produce synthetically versatile, optically active α-bromoesters is reported. A range of products is produced in high enantioselectivity and moderate to good chemical yields with retention of both upon scale-up. The reactions herein are catalyzed by cinchona alkaloid derivatives, with the best performance