Lewis acids as co-catalysts in Pd-based catalyzed systems of the octene-1 hydroethoxycarbonylation reaction

Abstract

In this work, in order to develop new, efficient, and environmentally friendly methods for the preparation of practically valuable esters of carboxylic acids, the hydroalkoxycarbonylation reaction of octene-1 with various alcohols in the presence of metal–complex catalysts based on palladium phosphine complexes has been studied. Three-component systems based on PdCl2(PPh3)2 containing different ligands as stabilizers and Lewis acids as promoters were studied as catalysts. It is shown that the three-component system PdCl2(PPh3)2–PPh3–AlCl3 has the highest catalytic activity in the reactions studied. It was found that the reaction of hydroalkoxycarbonylation of octene-1 proceeds with the formation of a mixture of linear (ethyl ester of pelargonic acid) and branched (ethyl ester of 2-methylcaprylic acid) products. The influence of the ratio of initial reagents (different olefins and alcohols) and components of catalytic systems (different Pd complexes, ligands, and promoters) on the course of the process has been investigated, in which the conversion of octene-1 reached 88.5%. The optimal parameters of the reactions studied were determined.

Keywords

• carbonylation
• reppe synthesis
• octene-1
• lewis acids
• pd-complex catalysts