Three-Component Tandem Reaction Involving Acid Chlorides, Terminal Alkynes, and 2-Aminoindole Hydrochlorides: Synthesis of α-Carboline Derivatives in Aqueous Conditions via Regioselective [3+3] Cyclocondensation

An efficient synthesis toward highly diversified a-carboline derivatives via a three-component tandem reaction using acid chlorides, terminal allcynes, and 2-aminoindole hydrochlorides has been described. The salient feature of the one-pot strategy involves regioselective [3 + 3]-cyclocondensation and the presence of water in the reaction medium to facilitate cyclizafion. Nonaqueous conditions furnished products in poor yields.