Catalytic carbonyl–olefin metathesis reactions represent powerful synthetic strategies for alkene formation. Successful approaches for carbonyl–olefin ring-closing, ring-opening and cross metathesis have been developed in recent years, but current limitations hamper the generality of these transformations. Stronger, more efficient catalytic systems are needed to further broaden the scope of these transformations while they prevent undesired reaction pathways. Here we report the development of an aluminium-based heterobimetallic ion pair as a superior catalyst that promotes carbonyl–olefin ring-closing metathesis via a distinct reaction mechanism and allows access to six- and seven-membered rings, which suffer from low yields and poor conversion under previously reported conditions. Mechanistic investigations support a distinct reaction profile in which two productive reaction pathways competitively form metathesis products. These insights are expected to have important implications in the catalyst design and development for carbonyl–olefin metathesis and enable future advances to ultimately expand the synthetic utility of these transformations.

催化羰基-烯烃复分解反应代表了形成烯烃的强大合成策略。近年来，已经开发出成功的羰基-烯烃开环，开环和交叉复分解方法，但是目前的局限性限制了这些转化的普遍性。需要更强大，更有效的催化系统，以进一步拓宽这些转化的范围，同时防止不必要的反应途径。在这里，我们报告铝基杂双金属离子对作为高级催化剂的发展，该催化剂通过独特的反应机理促进羰基-烯烃环的复分解反应，并允许进入六元和七元环，这些环收率低且性能差在先前报告的条件下进行转化。机理研究支持独特的反应谱，其中两个生产性反应途径竞争性地形成复分解产物。预计这些见解将对羰基-烯烃复分解反应的催化剂设计和开发产生重要影响，并使未来的进展最终扩展这些转化的合成效用。