Tuning Ligand-Electronics in Iridium Pincer Complexes Enables Increased Activity in Acceptorless Alcohol Dehydrogenation

High Resolution Image Download MS PowerPoint Slide Acceptorless alcohol dehydrogenation (AAD) converts alcohols to carbonyl compounds with concurrent hydrogen evolution, providing a sustainable and atom-efficient oxidation pathway. Here, we examine how electronic modifications of POCOP-type iridium pincer catalysts influence this transformation. A CF 3 -substituted complex exhibits a 3–7 times higher initial turnover frequency relative to the parent system in the dehydrogenation of 1-phenylethanol. Kinetic analysis shows that this enhancement reflects a lower intrinsic β-hydride elimination barrier, although slow hydrogen mass transfer partially masks the full activity advantage at elevated temperatures. These results establish ligand electronic manipulation as a direct method for accelerating AAD catalysis rather than merely improving stability.