An in situ procedure for catalytic, enantioselective acetate aldol addition. Application to the synthesis of (R)-(−)-epinephrine
作者:Robert A. Singer、Erick M. Carreira
DOI:10.1016/s0040-4039(96)02515-4
日期:1997.2
experimental procedure for the enantioselective, catalytic acetate aldol addition reaction. The addition of Me3SiCl and Et3N circumvents the azeotropic removal of the released isopropanol upon treating ligands 1 and 2 with Ti(OiPr)4. Importantly, this new procedure maintains the salient features of the catalytic process we originally described: high yields and enantioselectivities, low catalyst loads, and
我们报道了催化剂3的原位制备,其实质上简化了对映选择性的,催化的乙酸酯羟醛加成反应的实验程序。Me 3 SiCl和Et 3 N的添加避免了用Ti(O i Pr)4处理配体1和2时共沸除去释放的异丙醇。重要的是,这种新方法保持了我们最初描述的催化过程的显着特征:高收率和对映选择性,低催化剂负载以及便捷的反应时间和温度。我们已将新程序应用于(R来自商业试剂的)-(-)-肾上腺素,总产率为45%。