Understanding asymmetric hydrogenation of alkenes catalyzed by the first-row transition metal Fe: a first-principles exploration

First-principles analyses were performed for understanding the mechanistic details of Fe-catalysed asymmetric hydrogenation of alkenes in the presence of silane that has recently been experimentally realized. The catalytic hydrogenation is expected to proceed through initial hydride transfer from Fe-H to the CC bond of alkene, followed by σ-bond metathesis of hydrosilane to afford a chiral alkane product and an iron silyl species, which then reacts with H₂ to regenerate the iron hydride species via another σ-bond metathesis. The mechanistic details and the origin of the regioselectivity and stereoselectivity of these reactions are understood on the basis of detailed potential energy surface analysis, charge transfer and noncovalent interactions involved therein, strain energy and isodesmic studies in the solvated stage. Finally, general aspects are highlighted for guiding further experimental studies to precisely control the reaction scheme.