Heterolytic H_2 Cleavage and Catalytic Hydrogenation by an Iron Metallaboratrane

Reversible, heterolytic addition of H_2 across an iron–boron bond in a ferraboratrane with formal hydride transfer to the boron gives iron-borohydrido-hydride complexes. These compounds catalyze the hydrogenation of alkenes and alkynes to the respective alkanes. Notably, the boron is capable of acting as a shuttle for hydride transfer to substrates. The results are interesting in the context of heterolytic substrate addition across metal–boron bonds in metallaboratranes and related systems, as well as metal–ligand bifunctional catalysis.