Ligand-induced suppression of undesirable pathways in cobalt-catalyzed hydroformylation

Hydroformylation, an industrial process yielding over 10 million tons of oxo-alcohols annually, faces increasing economic pressures linked to rhodium-based catalysts, particularly in propene hydroformylation. This has prompted the search for alternative metal catalysts. Cobalt-based hydroformylation catalysts, predating rhodium counterparts, were initially restricted to long-chain alkenes due to rigorous reaction conditions. Despite recent progress in enhancing cobalt-catalyzed hydroformylation reactivity, the challenge of effectively reducing side reactions such as hydrogenation and isomerization remains. In this study, we leverage the ligand effect to enhance reactivity and selectivity. We examine the briphos ligand series and identify an optimized ligand demonstrating outstanding reactivity and selectivity across various alkenes, primarily yielding aldehydes as the primary products. Additionally, computational insights elucidate the crucial role of ligands in determining selectivity. Lastly, we demonstrate cobalt-catalyzed propene hydroformylation using Co/briphos.