Single-Operation Deracemization of 3H-Indolines and Tetrahydroquinolines Enabled by Phase Separation
摘要:
The single-operation deracemization of 3H indolines and tetrahydroquinolines is described. An asymmetric redox approach was employed, in which a phosphoric acid catalyst, oxidant, and reductant are present in the reaction mixture. The simultaneous presence of both oxidant and reductant was enabled by phase separation and resulted in the isolation of highly enantioenriched starting materials in high yields.
Asymmetric Pnictogen-Bonding Catalysis: Transfer Hydrogenation by a Chiral Antimony(V) Cation/Anion Pair
作者:Jian Zhang、Jun Wei、Wei-Yi Ding、Shaoyu Li、Shao-Hua Xiang、Bin Tan
DOI:10.1021/jacs.1c02808
日期:2021.5.5
Pnictogen-bonding catalysisbased on σ-hole interactions has recently attracted the attention of synthetic chemists. As a proof-of-concept for asymmetric pnictogen-bonding catalysis, we report herein an enantioselective transfer hydrogenation of benzoxazines catalyzed by a novel chiral antimony cation/anion pair. The chiral pnictogen catalyst library could be rapidly accessed from triarylstibine with
Highly Enantioselective Synthesis of Indolines: Asymmetric Hydrogenation at Ambient Temperature and Pressure with Cationic Ruthenium Diamine Catalysts
作者:Zhusheng Yang、Fei Chen、Yanmei He、Nianfa Yang、Qing-Hua Fan
DOI:10.1002/anie.201607890
日期:2016.10.24
asymmetric hydrogenation of 1H‐indoles and 3H‐indoles at ambient temperature and pressure, catalyzed by chiral phosphine‐free cationic ruthenium complexes, has been developed. Excellent enantio‐ and diastereoselectivities (up to >99 % ee, >20:1 d.r.) were obtained for a wide range of indolederivatives, including unprotected 2‐substituted and 2,3‐disubstituted 1H‐indoles, as well as 2‐alkyl‐ and 2‐aryl‐substituted
Continuous-flow catalytic asymmetric hydrogenations: Reaction optimization using FTIR inline analysis
作者:Magnus Rueping、Teerawut Bootwicha、Erli Sugiono
DOI:10.3762/bjoc.8.32
日期:——
The asymmetric organocatalytic hydrogenation of benzoxazines, quinolines, quinoxalines and 3H-indoles in continuous-flow microreactors has been developed. Reaction monitoring was achieved by using an inline ReactIR flow cell, which allows fast and convenient optimization of reaction parameters. The reductions proceeded well, and the desired products were isolated in high yields and with excellent enantioselectivities.
chiral diiron complexes exhibit efficient catalytic reactivity in dehydrogenative kineticresolution of indolines using environmentally benign hydrogen peroxide as oxidant. In particular, complex C9 bearing sterically encumbered salan ligands and a 2-naphthoate bridge is identified as the optimal catalyst in terms of chiral recognition. Further investigation reveals that this MMO mimic chiral catalyst