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.