Tris(triphenylphosphine)rhodium Chloride is also known as Wilkinson's catalyst and is commonly used to catalyze the hydrogenation of alkenes. Tris(triphenylphosphine)rhodium(I) Chloride is also used in the catalytic hydroboration of alkenes with catecholborane and pinacolborane and the selective 1,4-reduction of α, β-unsaturated carbonyl compounds.