Six-Membered Cyclic (Alkyl)(amino)silylenes for Dehydrogenation of Ammonia Borane, Hydrogenation of CO ₂ , and Unsaturated Bonds

A series of six-membered cyclic (alkyl)(amino)silylenes (CAASis) with structural modifications have been designed to probe their potential toward small molecule activations using density functional theory. Incorporation of a carbonyl group, silicon, and a boron atom adjacent to the amino group or annulation increases the π-acidity of the silylene center. All of the CAASis possess promising ligand properties and may be considered potential candidates for metal-free activation and functionalization of industrially relevant molecules. Based on the computed energetics, the proposed silylenes are predicted to be capable of efficient activation of the H-H bond of H₂, cycloaddition of C₂H₂, dehydrogenation of ammonia borane, hydrogenation of CO₂, and other organic substrates.