Study of Pd-elimination under carbonylation conditions: Regioselective formation of esters

Article abstract of DOI:10.1016/S0040-4020(98)00852-7

The regioselective synthesis of methyl esters is achieved by carbonylation of two different types of organometallic derivatives resulting from insertion of non-conjugated dienes into a Pd-aryl bond. When the diene and the Pd-aryl synthon [PdPfBr(NCMe)₂] (Pf = C₆F₅) are mixed at low temperature, solutions of η¹-η²-enylpalladium complexes can be isolated and converted into β-aryl methyl esters by reaction with CO in the presence of methanolic solutions of sodium methoxide. When the reactions are carried out at room temperature η³-allylpalladium complexes are isolated, and their carbonylation gives β,γ-unsaturated esters.