Phosphine-Supported Earth-Abundant Transition-Metal Catalysts for Alkene Hydrogenation

Abstract Catalytic hydrogenation of alkenes is a cornerstone transformation in both industrial chemistry and synthetic methodology. While noble-metal catalysts have historically dominated this field, the development of efficient hydrogenation catalysts based on earth-abundant transition metals has emerged as a major research direction. Phosphine ligands play a central role in enabling such systems by stabilizing reactive metal centers, tuning electronic and steric environments, and facilitating diverse modes of H2 activation. This review highlights recent advances in phosphine-supported earth-abundant metal catalysts for alkene hydrogenation, focusing on representative systems based on Fe, Co, Ni, and Mn, together with several emerging metal platforms. Particular attention is given to ligand design strategies, catalyst structures, and mechanistic paradigms governing hydrogen activation and transfer, including classical metal-hydride insertion pathways, metal–ligand cooperative processes, and cooperative multisite activation. Despite significant progress, challenges remain in improving catalyst robustness, expanding substrate scope-especially for sterically hindered internal alkenes and developing broadly applicable asymmetric variants. Continued advances in phosphine ligand engineering and cooperative catalyst design are expected to further advance sustainable hydrogenation catalysis using earth-abundant metals.