Identification of ammonium chloride as an effective promoter of the asymmetric hydrogenation of a β-enamine amide

被引：48

作者：

Clausen, Andrew M. ^{[1
]}

Dziadul, Brianne ^{[1
]}

Cappuccio, Kristine L. ^{[1
]}

Kaba, Mahmoud ^{[1
]}

Starbuck, Cindy ^{[1
]}

Hsiao, Yi ^{[1
]}

Dowling, Thomas M. ^{[1
]}

机构：

[1] Merck & Co Inc, Proc Res & Dev Proc Res, Rahway, NJ 07065 USA

来源：

ORGANIC PROCESS RESEARCH & DEVELOPMENT | 2006年 / 10卷 / 04期

关键词：

D O I：

10.1021/op050232o

中图分类号：

O69 [应用化学];

学科分类号：

081704 ;

摘要：

An investigation into the cause of substrate specific hydrogenation performance variability was conducted. A significant and unexpected correlation was observed between apparent pH of a solution of the substrate and rate of conversion and enantioselectivity. This observation led to the examination of low and variable levels of native ammonium chloride in different lots of substrate. The presence of ammonium chloride was found to have a positive effect on reaction rate and enantioselectivity when controlled within a relatively narrow range. Optimal performance was achieved with a mole ratio of 1: 1 ammonium chloride to catalyst.

引用

页码：723 / 726

页数：4