Silver Catalyzed Domino Approach to 1,3-Dicarbosubstituted Isochromenes

We report herein the first example of the silver triflate catalysed synthesis of 1,3-dicarbo-substituted isochromene derivatives starting from 2-alkynyl(hetero)arylaldehydes and enolizable ketones. The reaction proceeds in a cascade fashion under mild heating with complete regioselectivity and moderate-to-good yields. In some cases, the reaction gives unexpected homodimeric products. Two competitive mechanistic paths for the formation of the desired isochromene derivatives and the homodimeric products are described.