Copper‐Catalyzed Direct Arylation of Indoles and Related (Hetero)arenes: A Ligandless and Solvent‐free Approach
Dilip K. Pandey, Anand B. Shabade, Benudhar Punji
Abstract
Abstract A ligandless and solvent‐free copper‐catalyzed method for the regioselective C−H bond arylation of indoles and related heteroarenes is reported. The use of CuCl efficiently catalyzes the direct coupling of diverse heteroarenes with aryl iodides via chelation‐assistance. This reaction could tolerate sensitive and structurally diverse functionalities, including halides, ethers, thioethers, amines, indolyl, pyrrolyl and carbazolyl groups. The directing group, 2‐pyridinyl can be smoothly removed to generate C‐2 arylated free‐ NH indoles, and the arylated indoles can further be functionalized into Tryptamine derivatives. Preliminary mechanistic study revealed a radical pathway for the arylation reaction. magnified image