Lewis Acid Catalyzed Formation of Tetrahydroquinolines via an Intramolecular Redox Process
摘要:
Polycyclic tetrahydroquinolines were prepared by an efficient Lewis acid catalyzed 1,5-hydride shift, ring closure sequence. Gadolinium triflate was Identified as a catalyst that Is superior to scandium triflate as well as other Lewis acids. An approach toward a catalytic enantioselective variant Is also described.
Catalytic Enantioselective tert-Aminocyclization by Asymmetric Binary Acid Catalysis (ABC): Stereospecific 1,5-Hydrogen Transfer
作者:Liujuan Chen、Long Zhang、Jian Lv、Jin-Pei Cheng、Sanzhong Luo
DOI:10.1002/chem.201201532
日期:2012.7.16
Selective H transfer by ABC: A new asymmetric binary acid catalyst was developed to promote 1,5‐H transfer specifically and stereoselectively in tert‐aminocyclization reactions with excellent activity, high enantioselectivity, and broad substrate scope. The H atom (in red) was proven to transfer through a stereospecific suprafacial pathway (see scheme).