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
Visible Light‐Induced Decarboxylative Alkylation of Heterocyclic Aromatics with Carboxylic Acids via Anthocyanin as a Photocatalyst
作者:Rui Guo、Minghui Zuo、Qinye Tian、Chuanfu Hou、Shouneng Sun、Weihao Guo、Hongfeng Wu、Wenyi Chu、Zhizhong Sun
DOI:10.1002/asia.202000277
日期:2020.7
A visiblelight‐induced decarboxylative alkylation of heterocyclic aromatics with aliphatic carboxylicacids was developed by using anthocyanins as a photocatalyst under mild conditions. A series of alkylated heterocyclic compounds were obtained in moderate to good yields by using the metal‐free decarboxylative coupling reaction under blue light. This strategy uses cheap and readily available carboxylic
§ These authors contributed equally to this work Published as part of the 50 Years SYNTHESIS – Golden Anniversary Issue Abstract The visible-light-promoted oxidant-free decarboxylative C–H adamantylation of azoles was accomplished under ambient reaction conditions. The novel acridinium photocatalyst and cobalt synergistic catalysis enabled the C–H adamantylation under oxidant-free reaction conditions
general alkylation of heterocycles using a simple palladium catalyst is reported. Most classes of heterocycles, including indoles and pyridines, efficiently coupled with unactivated secondary and tertiary alkylhalides. An alkyl radical addition to neutral heteroarenes is most likely involved.
Visible-Light Photoredox-Catalyzed Decarboxylative Alkylation of Heteroarenes Using Carboxylic Acids with Hydrogen Release
作者:Wan-Fa Tian、Chun-Hong Hu、Ke-Han He、Xiao-Ya He、Yang Li
DOI:10.1021/acs.orglett.9b02539
日期:2019.9.6
Herein, we have developed visible-lightphotoredox-catalyzed decarboxylating carboxylic acids for alkylation of heteroarenes under mild conditions. The transformation occurred smoothly without the requirement of stoichiometric oxidants in the presence of 0.3 equiv of base, which benefited from the release of hydrogen (H2) and carbon dioxide (CO2). Various substrates and functional groups were tolerated