Palladacycle

In the 1960s, Arthur C. Cope and Robert W. Siekman reported the cyclopalladation reaction between aromatic azobenzenes and palladium(II) dichloride.

Derivatives of tris(o-tolyl)phosphine proved effective in Heck reactions.

Depending on the nature of the coordinating ligands, the neutral palladacycles can be monomers, dimers, or bis-cyclopalladated.

Other types of reactions such as transmetalation[6] and nucleopalladation[7] also turned out to be effective methods in the synthesis of palladacycles.

In the example of 2-aminobiphenyl palladacycles, a kinetically active 12-electrons Pd(0) species is formed, allowing for further oxidative addition with reactants.

[13][14] Except their abilities in catalyzing organic reactions, palladacycles have also shown their potential in medicinal and biological chemistry after the success of cis-Pt(NH3)2Cl2 as an anticancer agent.