A highly efficient three-component coupling of aldehyde, alkyne, and amines via C-H activation catalyzed by gold in water.

A highly efficient three-component-coupling of aldehyde, alkyne, and amine (A3 Coupling) catalyzed by gold via C-H activation was developed in water. The reaction is general, and nearly quantitative yields of the corresponding propargylamines were obtained in most cases. Both aromatic and aliphatic aldehydes and amines can be used for the reaction. No additional cocatalyst or activator is required. A mechanistic rationale for the reaction has been proposed.