Abstract

Considering the current challenges of the A³ redox-neutral C1-alkynylation of tetrahydroisoquinolines (THIQs), we studied this synthetic tool under visible light photocatalysis and transition-metal catalysis in order to describe alternative reaction conditions and discuss possible improvements to this process. We demonstrated that 1-alkynylated THIQs can be readily obtained by three different approaches: iridium-based photocatalysis and copper ([CuBr(PPh₃)₃]) and silver (AgNO₃) catalysis under mild, selective and accessible reaction conditions. Among these approaches, the copper(I)-based methodology resulted in the most robust, optimal reaction conditions for the synthesis of a series of 18 1-alkynylated THIQs in moderate to excellent yields and with high selectivity for the endo-alkynylated products. Moreover, this reaction can be accelerated by microwave irradiation (120 °C, 15 min) affording a novel library of diverse THIQs with alkyne and N-substituent moieties, from unreactive and uncommon substrates, that could be further transformed into new compounds of interest.

Publication History

Received: 02 June 2020

Accepted after revision: 03 August 2020

Publication Date:
21 September 2020 (online)

© 2020. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

中文翻译：

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四氢异喹啉的A3氧化还原中性C1-炔基化：可见光光催化和过渡金属催化的比较研究

摘要

考虑到四氢异喹啉（THIQ）的A ³氧化还原中性C1烷基化的当前挑战，我们研究了在可见光光催化和过渡金属催化下的这种合成工具，以描述替代的反应条件并讨论对该方法的可能改进。我们证明了可以通过三种不同的方法轻松获得1-炔基THIQs：基于铱的光催化和铜（[CuBr（PPh ₃）₃ ]）和银（AgNO ₃）在温和，选择性和可及的反应条件下进行催化。在这些方法中，铜（I）基的方法导致了最稳健的，最佳的反应在中等至良好的产率的条件的一系列18 1-炔基化THIQs的合成和与用于高选择性内切-alkynylated产品。此外，可以通过微波辐射（120°C，15分钟）来加速该反应，从而提供了一个新型THIQs库，该库具有未反应和不常见的底物，具有炔烃和N-取代基部分，可以进一步转化为新的目标化合物。

出版历史

收到：2020年6月2日

修订后接受：2020年8月3日

发布日期：
2020年9月21日（在线）

©2020年。Thieme。版权所有

Georg Thieme Verlag
KGRüdigerstraße14，70469斯图加特，德国