Chemo- and enantioselective hydrosilylation of carbonyl and imino groups. An emphasis on non-traditional catalyst systems

The scope of hydrosilylation of carbonyl and imine compounds in synthesis has greatly expanded because of the wide array of catalyst systems that are now available for these reactions. Beside rhodium and titanium complexes that have retained most attention in the past decades, new catalyst systems based on less traditional transition metals and on main group elements have recently emerged, that enable outstanding achievements in chemo- and/or enantioselective transformations. Also, investigators have focused on the development of friendly, cost-effective processes; utilization of safe and inexpensive polyhydrosiloxanes such as PMHS (polymethylhydrosiloxane) instead of the usual molecular hydrosilanes and direct reduction of carbonyl compounds in protic solvents have attained high synthetic efficacy. This review will cover the development and application of these new hydrosilylation catalyst systems.