Palladium carboxylate π-complexes with unsaturated hydrocarbons and the reactions catalyzed by them

This review summarizes the studies on the palladium carboxylate pi-complexes with unsaturated hydrocarbons (alkenes, alkynes, and arenes) as well as with N-heterocyclic carbenes, phosphonyl-substituted ferrocene ligands, etc. In these complexes the palladium atoms are coordinated with unsaturated hydrocarbons via the carbon atoms forming the multiple bonds. These complexes are traditional objects in fundamental coordination chemistry including chemistry of polynuclear compounds. They are also applied as pre-catalysts and as model intermediates for catalytic transformations of unsaturated hydrocarbons, e.g., oxidation and isomerization of alkenes, hydrogenation and coupling reactions of alkenes, alkynes, and arenes.