The First General, Efficient and Highly Enantioselective Reduction of Quinoxalines and Quinoxalinones
作者:Magnus Rueping、Francisco Tato、Fenja. R. Schoepke
DOI:10.1002/chem.200902907
日期:——
Simple yet efficient: A series of diverse substituted tetrahydroquinoxalines and dihydroquinoxalinones have been synthesized for the first time in a highly enantioselective fashion (see scheme). Using this metal‐free hydrogenation it is possible to isolate these products, which are of high pharmaceutical interest, in good yields and with excellent enantioselectivities in a minimal number of reaction
disproportionation of dihydroquinoxalines for the synthesis of chiral tetrahydroquinoxalines using a metal/Brønstedacidrelaycatalysissystem has been developed. The use of hydrogen gas as the reductant makes the convergent disproportionation an ideal atom-economical process. A dramatic reversal of enantioselectivity was observed in the reduction of quinoxalines because of the different steric demands in
Asymmetric Transfer Hydrogenation of 2-Substituted Quinoxalines with Regenerable Dihydrophenanthridine
作者:Zaiqi Han、Xiangqing Feng、Haifeng Du
DOI:10.1021/acs.joc.3c02954
日期:2024.3.1
represents one of the most efficient approaches for the synthesis of optically active tetrahyroquinoxalines. In this paper, we demonstrate a metal-free asymmetric transfer hydrogenation of 2-substituted quinoxalines with regenerable dihydrophenanthridine under H2 using a combination of chiral phosphoric acid and achiral borane as catalysts. A wide range of optically active 2-substituted tetrahydroquinoxalines
喹喔啉的不对称氢化是合成光学活性四氢喹喔啉的最有效方法之一。在本文中,我们展示了在H 2下,使用手性磷酸和非手性硼烷作为催化剂,2-取代的喹喔啉与可再生二氢菲啶的无金属不对称转移氢化。以≤98% ee 的高产率生产了多种光学活性 2-取代四氢喹喔啉。