1,4‐ and 1,5‐diols undergo cyclodehydration upon treatment with cationic N‐heterocyclic carbene (NHC)–IrIII complexes to give tetrahydrofurans and tetrahydropyrans, respectively. The mechanism was investigated, and a metal‐hydride‐driven pathway was proposed for all substrates, except for very electron‐rich ones. This contrasts with the well‐established classical pathways that involve nucleophilic
1,4-和1,5
-二醇在用阳离子N-杂环卡宾(NHC)-Ir III络合物处理后发生环化
脱水,分别生成
四氢呋喃和
四氢吡喃。研究了该机制,并提出了一种适用于所有底物的
金属
氢化物驱动途径,除了电子非常丰富的底物。这与涉及亲核取代的成熟经典途径形成对比。