Harnessing metal-ligand cooperation in cobalt-catalyzed hydride transfer reactions of non-polar unsaturated compounds

Abstract

The development of efficient organometallic catalysts remains a long-standing goal in modern organic synthesis. While precious metal catalysts based on 4d and 5d transition metals have enabled numerous hydride transfer transformations, there is an increasing interest in earth-abundant 3d metal alternatives, which offer advantages in cost, sustainability, and access to distinct reactivity profiles. Among these, cobalt has emerged as a particularly versatile candidate, showing remarkable potential in catalytic hydride transfer chemistry. In this review, we summarize our recent efforts to develop a family of pincer cobalt complexes that leverage metal-ligand cooperation (MLC) to overcome key challenges in cobalt-catalyzed hydride transfer reactions. Special emphasis is placed on catalyst design principles and their applications in transformations of non-polar unsaturated compounds, including olefin isomerization and the semihydrogenation of alkynes and allenes. We anticipate that these MLC-based design strategies will offer valuable guidance for the future development of efficient and sustainable catalysts based on earth-abundant metals.