Synthesis of indole-2-, 3-, or 5-substituted propargylamines via gold(III)-catalyzed three component reaction of aldehyde, alkyne, and amine in aqueous medium

A simple and efficient route to indole-2-, 3-, or 5-substituted propargylamines by three component-coupling of substituted indole carboxaldehydes, terminal alkyne, and secondary amine in the presence of AuBr3 catalyst in aqueous medium, is described. This protocol provides a concise and effective route toward the synthesis of a variety of indole-2-, 3-, or 5-substituted propargylamines in excellent yields.