Carbonyl‐Alkyne Metathesis Reactions Catalyzed by Organic Halogen‐Bond Donors

The carbonyl‐alkyne metathesis reaction is a powerful method for the synthesis of a,b‐unsaturated carbonyls. We now report on the development of a halogen‐bond catalyzed protocol for both the intra‐ and intermolecular reaction. Our studies revealed that methanol is a highly efficient solvent and that a very broad range of functional groups are tolerated under the reaction conditions. Mechanistic studies support the proposed halogen‐bond interaction. Furthermore, the halogen‐bond protocol is compared with other available catalytic systems for these reactions.