Boosting catalyst activity in cis-selectiv semi-reduction of internal alkynes by tailoring the assembly of all-metal aromatic tri-palladium complexes

Highly symmetric [Pd-3](+) clusters that present delocalized metal-metal bonds can catalyse the selective semi-reduction of internal alkynes to cis-alkenes. Studies on factors governing the formation of all-metal aromatics enabled the design of an optimised catalytic system that delivers cis-alkenes with almost complete selectivity on a gram scale with very low catalyst loadings (0.03 mol%).