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Paper | Regular issue | Vol 98, No. 7, 2019, pp.904-915
Published online, 11th June, 2019
DOI: 10.3987/COM-19-14092
Divergent Synthesis of Indole-2-carboxylic Acid Derivatives via Ligand-Free Copper-Catalyzed Ullmann Coupling Reaction

Jiadi Zhou, Yongjian Chen, Junsong Huang, and Jianjun Li*

*Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou 310014, P. R. China

Abstract

This article describes a ligand-free copper-catalyzed Ullmann coupling reaction for the preparation of divergent indole-2-carboxylic acid derivatives including esters, amides and anhydrides. Various compounds 3, which could be synthesized from aldehydes conveniently, were used as substrate to provide the corresponding indole-2-carboxylic acid derivatives in moderate to good yields.