On the Enantioselective Phosphoric-Acid-Catalyzed Hantzsch Synthesis of Polyhydroquinolines

A reinvestigation of a chiral phosphoric-acid-catalyzed four-component Hantzsch enantioselective synthesis of polyhydroquinolines reported in 2009 is presented. In our hands, when the reaction was performed with fidelity to the original report using a chiral enantiopure phosphoric acid catalyst, no enantioselectivity was observed. Unlike in the original report, enantioselectivity results are backed by baseline separation of the enantiomers by HPLC analyses on chiral stationary phase with UV and chiroptical detection.本文对2009年报道的手性磷酸（chiral phosphoric acid）催化四组分汉茨希（Hantzsch）对映选择性合成多氢喹啉的研究进行了复现验证。在我们的实验中，当严格遵循原始报道的实验方案，使用对映纯手性磷酸催化剂进行反应时，未观察到对映选择性。与原始报道不同，本研究的对映选择性结果通过手性固定相高效液相色谱（High Performance Liquid Chromatography，HPLC）结合紫外与旋光检测实现对映异构体基线分离的分析结果予以佐证。