CsOH-Promoted Regiospecific Sulfenylation, Selenylation, and Telluration of Indoles in H2 O.

Various indole-containing compounds have shown impressive pharmaceutical activities against a variety of diseases. However, the functionalization of indoles usually relies on systems that use organic solvents, which do not meet the criteria for green and sustainable chemical development. To address this issue, regiospecific sulfenylation, selenylation, and telluration of indoles were developed using H₂ O as solvent. The highly efficient chalcogenylation of indoles was achieved utilizing CsOH as a promoter, thus avoiding the use of expensive transition-metal catalysts. This newly developed protocol is characterized by its outstanding features including simple operation, mild conditions, wide substrate scope, excellent functional group tolerance, and recyclability, leading to the convenient synthesis of 3-chalcogenyl-indoles. [ABSTRACT FROM AUTHOR]