LAUSR

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 co-catalytic metal sites. Unique reactivity and selectivity patterns with non-precious elements that have emerged from successful implementation of these strategies in catalytic transformations are emphasized.