A Copper Catalyst with a Cinchona-Alkaloid-Based Sulfonamide Ligand for Asymmetric Radical Oxytrifluoromethylation of Alkenyl Oximes
作者:Xi-Tao Li、Qiang-Shuai Gu、Xiao-Yang Dong、Xiang Meng、Xin-Yuan Liu
DOI:10.1002/anie.201804315
日期:2018.6.25
A copper‐catalyzed asymmetric radical oxytrifluoromethylation of alkenyl oxime and Togni's reagent has been successfully developed, thereby providing straightforward access to CF3‐containing isoxazolines bearing α‐tertiary stereocenters with excellent yield and enantioselectivity. The key to success is the rational design of cinchona‐alkaloid‐based sulfonamides as neutral/anionic hybrid ligands to
A hydroxy group chelation‐assisted stereospecific oxidative cross‐coupling reaction between alkenes was developed under mild reaction conditions. In the presence of palladium catalyst, the alkenes tethered with hydroxy functionality can couple efficiently with electron‐deficient alkenes to form the corresponding multi‐substituted olefin products. The hydroxy group on the substrate could play dual roles
Pd-Catalyzed Asymmetric Acyl-Carbamoylation of an Alkene to Construct an α-Quaternary Chiral Cycloketone
作者:Min Liu、Xing Wang、Ziqiong Guo、Hanyuan Li、Wei Huang、Hui Xu、Hui-Xiong Dai
DOI:10.1021/acs.orglett.1c02093
日期:2021.8.20
Herein, we report the palladium-catalyzed asymmetric acyl-carbamoylation of an alkene by employing thioesters as the acyl electrophiles and t-BuNC as the carbamoyl reagent, affording an α-quaternary chiral cycloketone in synthetically useful yields with excellent enantioselectivity. The reaction proceeded via asymmetric 1,2-migratory insertions of acyl-Pd into alkenes and subsequent migratory insertion
Highly Flexible Synthesis of Chiral Azacycles via Iridium-Catalyzed Hydrogenation
作者:J. Johan Verendel、Taigang Zhou、Jia-Qi Li、Alexander Paptchikhine、Oleg Lebedev、Pher G. Andersson
DOI:10.1021/ja103901e
日期:2010.7.7
A range of saturated chiral azacycles has been prepared in high yield and with high selectivity from simple starting materials. A modular approach with ring-closing metathesis as a keystep was used to produce a number of five-, six-, and seven-membered cyclic alkenes. Asymmetrichydrogenationcatalyzed by N,P-ligated iridium complexes gave saturated azacycles in high optical purity. This methodology