Molecular mechanism of alkene hydrosilylation in the molecular cavity of cucurbituril

Transition metal catalysts have been widely used in hydrosilylation reactions. However, these catalysts result in many adverse consequences for precise control of reactions and sustainable development of valuable resources. In this work, a transition metal-free catalytic strategy is proposed, which is a supramolecular catalysis based on cucurbituril (CB[n]) as a reaction container. To shed new insight into the alkene hydrosilylation, DFT calculations are carried out at the ωB97XD/6-311G(d,p) level of theory. The geometrical structures, frontier molecular orbitals, non-covalent interactions, thermodynamics, and kinetics of the reaction systems are discussed systematically. It is found that CB6 can catalyze the title hydrosilylation by activating the reactants, reducing the reaction barriers, and increasing the reaction rate constants. This finding will bring a new opportunity for the development of hydrosilylation reactions.