Brønsted Acid‐Catalyzed Carbonyl‐Olefin Metathesis inside a Self‐Assembled Supramolecular Host

Abstract Carbonyl–olefin metathesis represents a powerful yet underdeveloped method for the formation of carbon–carbon bonds. So far, no Brønsted acid based method for the catalytic carbonyl–olefin metathesis has been described. Herein, a cocatalytic system based on a simple Brønsted acid (HCl) and a self‐assembled supramolecular host is presented. The developed system compares well with the current benchmark catalyst for carbonyl–olefin metathesis in terms of substrate scope and yield of isolated product. Control experiments provide strong evidence that the reaction proceeds inside the cavity of the supramolecular host. A mechanistic probe indicates that a stepwise reaction mechanism is likely.