Verdaguer Xavier, Lange Udo E W, Buchwald Stephen L
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139 (USA), Fax: (+1) 617-253-3297.
Angew Chem Int Ed Engl. 1998 May 4;37(8):1103-1107. doi: 10.1002/(SICI)1521-3773(19980504)37:8<1103::AID-ANIE1103>3.0.CO;2-M.
Slow addition of a primary amine to the reaction mixture greatly increases the scope of the titanium-catalyzed asymmetric reduction of imines 1. An important added feature of this method is that chiral secondary amines 2 can be obtained in much higher optical purity (up to 99 % ee) than would be predicted from the E:Z ratios of the starting imines 1.
向反应混合物中缓慢加入伯胺可大大拓宽钛催化的亚胺1不对称还原反应的适用范围。该方法的一个重要附加特点是，与根据起始亚胺1的E:Z比例预测的结果相比，所获得的手性仲胺2的光学纯度要高得多（高达99% ee）。
