Computational design of metal-free molecules for activation of small molecules, hydrogenation, and hydroamination

Hydrogen activation is a key step in hydrogenation reactions which are widely used in both laboratory synthesis and the chemical industry. Traditionally, it was often considered that only transition metal complexes/systems are able to activate hydrogen and to catalyze hydrogenations. This view has been changed recently; more and more metal-free molecules/systems have been found capable of activating hydrogen. Among these developments, the frustrated Lewis pairs (FLPs) are of particular significance, not only because they exhibit high reactivity toward hydrogen as well as other small molecules, but also because some of them can perform direct catalytic hydrogenations, which pave the way to the development of cheaper and greener hydrogenation catalysts. Inspired by the FLP principle, we used quantum mechanics computations to design molecules for H₂, CH₄, and NH₃ activation and catalysts for hydrogenation of imines, ketones, and alkenes. While our designed molecules are awaiting experimental preparation, the active sites in our designed molecules anticipated the features appeared in the compounds synthesized later by experimentalists. This chapter reviews our computational explorations to enrich FLP chemistry.