Reversible C–C Double Bond Cleavage to Form a Metal Carbene and an Alkene Enabled on an Iridium Complex Bearing a Pincer-type Alkoxycarbene Ligand

An iridium complex bearing a pincer-type alkoxycarbene ligand was prepared, and its reactivity was investigated. When a cationic dicarbonyl iridium complex bearing a pincer-type alkoxycarbene ligand was treated with terminal alkenes, it gave alkene-coordinated complexes via formation of a double bond between the carbene carbon and the terminal olefinic carbon. Moreover, this reaction was found to be reversible, and C–C double bond cleavage of the coordinated alkene proceeded to regenerate the iridium carbene complex and the starting alkene by heating the complex under a CO atmosphere. This carbene generation pathway is important as an elementary step to generate metal carbenes from alkenes.