Mechanistic Studies on a Cu-Catalyzed Aerobic Oxidative Coupling Reaction with N-Phenyl Tetrahydroisoquinoline: Structure of Intermediates and the Role of Methanol As a Solvent
摘要:
The mechanism of an aerobic copper-catalyzed oxidative coupling reaction with N-phenyl tetrahydroisoquinoline was investigated. The oxidized species formed from the reaction of the amine with the copper catalyst were analyzed by NMR-spectroscopy. An iminium dichlorocuprate was found to be the reactive intermediate and could be structurally characterized by X-ray crystallography. The effect of methanol to effectively stabilize the iminium ion was investigated and shown to be beneficial in an oxidative allylation reaction.
electron-donor–acceptor (EDA) complex between the N-aryl tetrahydroisoquinolines and an allyl or a benzylbromide. Irradiation with purple light triggered single-electron transfer (SET) from the N-aryl tetrahydroisoquinolines to the allyl or benzylbromide of the EDA complex, inducing the formation of the corresponding allyl or benzyl radical and the subsequent radical–radical coupling. This approach represents
Carbon Nitride-Catalyzed Photoredox Sakurai Reactions and Allylborations
作者:Lennart Möhlmann、Siegfried Blechert
DOI:10.1002/adsc.201400551
日期:2014.9.15
photocatalytic, oxidative CC coupling has grown to a well‐established methodology, especially for the modification of aryl‐substituted tetrahydroisoquinoline derivatives. However, until now, this reaction is mainly restricted to the usage of strong nucleophiles like nitroalkanes, cyanides, enamines, phosphonates and malonates. Within this publication we present an extension of such a method towards
在过去的几年中,光催化的C CC偶联已经发展成为一种完善的方法,特别是用于芳基取代的四氢异喹啉衍生物的修饰。但是,到目前为止,该反应主要限于使用强亲核试剂,如硝基烷,氰化物,烯胺,膦酸酯和丙二酸酯。在该出版物中,我们介绍了这种方法的扩展,适用于较弱的亲核试剂,即烯丙基锡烷,烯丙基硅烷和烯丙基硼烷。因此,发明了一种非常简单的方案,使用非均质中孔石墨氮化碳(mpg-C 3 N 4)作为催化剂,空气作为氧化剂,从而为多种基材提供了高收率。
Mechanistic Studies on a Cu-Catalyzed Aerobic Oxidative Coupling Reaction with <i>N</i>-Phenyl Tetrahydroisoquinoline: Structure of Intermediates and the Role of Methanol As a Solvent
The mechanism of an aerobic copper-catalyzed oxidative coupling reaction with N-phenyl tetrahydroisoquinoline was investigated. The oxidized species formed from the reaction of the amine with the copper catalyst were analyzed by NMR-spectroscopy. An iminium dichlorocuprate was found to be the reactive intermediate and could be structurally characterized by X-ray crystallography. The effect of methanol to effectively stabilize the iminium ion was investigated and shown to be beneficial in an oxidative allylation reaction.