Catalytic reductive coupling of alkenes and alkynes to carbonyl compounds and imines mediated by hydrogen

Catalytic transformations mediated by hydrogen or "hydrogenations" encompass a diverse range of environmentally benign processes, including large volume transformations of enormous socioeconomic impact, such as the Haber-Bosch process and the reduction of olefinic feedstocks. Despite considerable progress across diverse areas of catalytic hydrogenation, reductive C - C bond formations mediated by hydrogen have, until recently, been restricted to the incorporation of carbon monoxide, as illustrated by the Fischer-Tropsch reaction and alkene hydroformylation. In this account, the emerging family of hydrogen-mediated C - C bond formations beyond carbon monoxide coupling is reviewed. This new type of hydrogenation enables direct coupling of diverse pi-unsaturated reactants to carbonyl compounds and imines under neutral condition with complete atom economy.