Mechanistic Insights into the Chemo‐Selective Dehydrogenative Silylation of Alkenes Catalyzed by Bis(imino)pyridine Cobalt Complex from DFT Computations

Abstract

AbstractAn in‐depth theoretical study has been performed to investigate the mechanism of alkene dehydrogenative silylation catalyzed by the bis(imino)pyridine cobalt methyl complex (MesPDI)Co(CH3) on the singlet, triplet and open‐shell singlet potential energy surfaces as well as the corresponding minimum energy crossing points. The formation of active catalyst [(MesPDI)Co(CH3)+HSiR3→(MesPDI)Co−[Si]+CH4] follows an open‐shell singlet potential energy surface, while the active catalyst has a triplet ground state. For 1‐butene as substrate, the formation of E/Z‐allylsilanes follows the singlet surface; and the E‐allylsilane is more favored than the Z‐allylsilane kinetically, and the expected ratio agrees with the experiment. For bulky 4,4‐dimethyl‐1‐pentene as substrate, the selectivity of allylsilane and vinylsilane is thermodynamically determined and this is supported by the need of low silane/olefin ratio (1/4) in experiment.