Gold-Catalyzed Reactions of <i>o</i> -Alkynylarylaldehydes with Alkenes for the Synthesis of 3,4-Dihydronaphthalene Derivatives

Herein, we report a selective synthesis of 3,4-dihydronaphthalene derivatives from <i>o</i>-quinodimethane (<i>o</i>-QDM) intermediates by gold(I). This method is achieved through [(BINAP)₂Au₂(BAr^F₄)₂]-catalyzed reactions of <i>o</i>-alkynylarylaldehydes with alkenes following 1,5-H migration. The reaction features a broad substrate scope and excellent functional group tolerance. Notably, the catalytic system was highly efficient at 0.1 mol % loading for most reactions, which could be reduced to 0.05 mol % in gram-scale reactions while maintaining the yield. More significantly, the reaction enables late-stage modification of complex molecules, providing a new strategy for drug derivatization and efficient synthesis of bioactive trioxifene.