Gold vs Rhodium Catalysis: Tuning Reactivity through Catalyst Control in the C–H Alkynylation of Isoquinolones

A site-selective C-4/C-8 alkynylation of isoquinolones catalyzed by gold and rhodium complexes is reported. A broad range of synthetically useful functional groups (−F, −Cl, −Br, −CF₃, −OMe, alkyl, etc.) were tolerated, providing an efficient and robust protocol for the synthesis either C-4- or C-8-alkynylated isoquinolones