Cooperative Strategies for Catalytic Hydrogenation of Unsaturated Hydrocarbons

This Perspective discusses catalytic hydrogenation reactions of alkenes, alkynes, and other unsaturated C–C substrates in which the catalyst design involves cooperative strategies that enable bifunctional H2 activation and delivery. These approaches complement the more traditional use of single-site precious metal systems for such hydrogenation reactions in homogeneous catalysis. Strategies included in this Perspective are cooperation between (a) a catalytic metal site and a basic ligand residue, (b) a catalytic metal site and an acidic ligand residue, (c) frustrated acid/base pairs, and (d) two cocatalytic metal sites. Unique reactivity and selectivity patterns with nonprecious elements that have emerged from successful implementation of these strategies in catalytic transformations are emphasized.