Asymmetric reduction of ketimines 1a–f with trichlorosilane can be catalysed by the Lewis-basic N-methylvaline-derived formamide anchored to a soluble dendron (11c) with good enantioselectivity (≤94% ee) and low catalyst loading (typically 5 mol%) at room temperature in toluene. This protocol represents an improvement and simplification of the isolation procedure and recovery of the catalyst.
三
氯硅烷催化的不对称还原酮
亚胺1a–f可以通过附着于可溶性树枝状大分子上的由
N-甲基缬氨酸衍生的甲酰胺(11c)来催化,具有良好的对映选择性(≤94% 对映体过量)和极低的催化剂用量(通常为5摩尔%),在室温下的
甲苯中进行反应。这种方法简化了分离步骤并且可以回收催化剂,相比于以前的方案是一个改进。