Visible-Light-Driven Palladium-Catalyzed Radical Alkylation of C−H Bonds with Unactivated Alkyl Bromides
作者:Wen-Jun Zhou、Guang-Mei Cao、Guo Shen、Xing-Yong Zhu、Yong-Yuan Gui、Jian-Heng Ye、Liang Sun、Li-Li Liao、Jing Li、Da-Gang Yu
DOI:10.1002/anie.201704513
日期:2017.12.4
Reported herein is a novel visible‐light photoredox system with Pd(PPh3)4 as the sole catalyst for the realization of the first direct cross‐coupling of C(sp3)−H bonds in N‐aryl tetrahydroisoquinolines with unactivated alkyl bromides. Moreover, intra‐ and intermolecular alkylations of heteroarenes were also developed under mild reaction conditions. A variety of tertiary, secondary, and primary alkyl
本文报道了一种新型的可见光光氧化还原体系,其中Pd(PPh 3)4是实现N-芳基四氢异喹啉中C(sp 3)-H键与未活化烷基溴的第一个直接交叉偶联的唯一催化剂。此外,杂芳烃的分子内和分子间烷基化反应也在温和的反应条件下进行。各种叔,仲和伯烷基溴经过反应生成C(sp 3)-C(sp 3)和C(sp 2)-C(sp 3)债券,收益率中等至极高。这些氧化还原中性反应具有广泛的底物范围(> 60个示例),良好的功能基团耐受性和易于生成的四元中心。机理研究表明,简单的钯配合物充当可见光光催化剂,自由基参与该过程。