Gold-CatalyzedDifunctionalization of Activated Alkyneswith Organohalides: Access to 3‑Arylated and Alkenylated CoumarinDerivatives

Coumarin skeletons are significant structural units frequently used in the fields of synthetic chemistry, medicinal chemistry, and materials science. Herein, we report a hemilabile P,N-ligand-assisted gold-catalyzed difunctionalization of activated alkynes with organohalides. The reaction occurs effectively under mild conditions without requiring an external oxidant, producing a variety of 3-arylated and alkenylated coumarin derivatives in high to excellent yields. This method demonstrates a wide substrate tolerance and superb functional group compatibility and is also suitable for heteroaromatic substrates. Further mechanistic investigations strongly support the proposed mechanism of the reaction.