New Sustainable Pd(II)/Fe(III) Catalytic System Very Efficient in the Hydromethoxycarbonylation of 1-octene

Abstract

In order to increase the catalytic activity of the Pd(II)-complexes in the alcoxycarbonylation of 1-olefins, the presence in solution of a strong Brönsted acid together with a phosphine ligand is usually required. From an industrial point of view, such two additives, however, influenced the sustainability of the process mainly caused by the related corrosion of the reaction vessel and the toxicity of the phosphine ligand.
In this paper, the methoxycarbonylation of 1-octene has been efficiently carried out by using the [Pd(TsO)₂(PPh₃)₂]/FeCl₃ catalyst system. The catalyst is very active also without addition of PPh₃, reaching the TON of ca. 1300 (mol/mol) in 2 hours by using the
Fe(III)/Pd(II) = 400/1 (mol/mol) system. Such value is higher than the values obtained by using the traditional strong Brönsted acid TsOH or other Lewis acid such as AlCl₃, in the presence of PPh₃. The reaction takes place with the formation of two isomeric products of linear and branched structures with a yield towards the linear isomer of ca. 80%.