Hydrogen-Mediated C-C Bond Formation: A Broad New Concept in Catalytic C-C Coupling

摘要

Hydrogenation ranks among the most powerful catalytic methods employed industrially, accounting for over half of the chiral compounds made by man not produced via physical or enzymatic resolution. This fact portends an equally powerful approach to reductive C-C bond formations mediated by hydrogen: catalytic couplings achieved simply through the exposure of two or more molecules to gaseous hydrogen in the presence of a metallic catalyst. Whereas classical methods for the addition of C-nucleophiles to carbonyl compounds generally require stoichiometric preformation of moisture-sensitive orga-nometallics, "C-C bond forming hydro genation" enables direct coupling of diverse π-unsaturated reactants under neutral conditions with complete atom economy. In this Perspective, we describe the first systematic efforts toward the development of hydrogen-mediated C-C couplings beyond alkene hydro-formylation, transformations that add a new dimension to catalytic hydrogenation, one of chemistry's oldest and most broadly utilized processes (Scheme 1).