Alkenylation of ortho-palladated phenylglycine: synthesis of stilbene derivatives and 3-aryl-isoquinoline-1-carboxylates

Abstract The ortho-palladated phenylglycine derivative [Pd(µ-Cl)(C6H4C(H)(CO2Me)NH2-C,N)]2 (1) reacts with substituted styrenes R1C6H4CH=CH2 (2a–2f) to give two different compounds as a function of the reaction conditions. When the reaction was performed in chloroform under reflux, the stilbene derivatives [C6H4-1-(CH(CO2Me)(NH2))-2-(E)-(CH=CHC6H4R1)] (3a–3f) were obtained, but when the reaction was carried out in toluene under reflux, the 3-arylisoquinoline-1-carboxylates (4a–4f) were obtained instead. The method has distinct advantages over other methods in that it is simple and general, only one/two reaction steps are necessary to obtain the final product, the prefunctionalisation of the substrates is not mandatory and nor is the presence of ancillary ligands, and a regioselective mono-insertion of the alkenes is systematically observed.