The use of Lewis acid AlCl3as a promoter in the Pd-complex catalytic system of the cyclohexene hydroethoxycarbonylation reaction

Abstract

This paper presents the results of detailed studies of the possibility of using Lewis acid AlCl3as a promoter of the catalytic three-component system PdCl2(PPh3)2–PPh3–AlCl3in the hydroethoxycarbonylation reaction of cyclohexene at low carbon monoxide pressures (2.5 MPa). As a result a high catalytic activity of the three-component system was established and the reaction proceeds regioselectively with the formation of ethyl ether of cyclohexanecarboxylic acid. The optimal conditions of the process have been elaborated (molar ratio of the starting reagents [Cyclohexene]:[Ethanol] = 1:1; molar ratio of the components of the catalytic system = =[PdCl2(PPh3)2]:[PPh3]:[AlCl3] = 1:6:9; carbon monoxide pressure PCO=2.5MPa; process temperature T=120°C and reaction time τ= 5 h) at which the target product yield reaches 80.7%. To identify the obtained ethyl ester of cyclohexane carboxylic acid gas chromatographic analysis and mass-and IR-spectra were carried out. Based on the data obtained, a possible mechanism of the reaction route of cyclohexene carbonylation with carbon monoxide and ethanol in the presence of the three-component system PdCl2(PPh3)2–PPh3–AlCl3is pro-posed and discussed.

HYDROETHOXYCARBONYLATION OF CYCLOPENTENE IN THE PRESENCE OF A THREE-COMPONENT PdCl2(PPh3)2-PPh3-AlCl3 SYSTEM

“…Palladium complexes promoted by free ligand-forming agents and strong protic acids are the most promising catalysts for hydroalkoxycarbonylation reactions. Carbonylation reactions in the presence of palladium complexes significantly enriched the methods for obtaining carbonyl compounds [12][13][14]. The alkoxycarbonylation reactions in the presence of palladium make it possible to effectively convert unsaturated compounds, CO, and alcohols into the corresponding derivatives of carboxylic acids [15][16][17].…”

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

“…in the food industry. To address such Brönsted acid related problems, the Lewis acids are increasingly used, as they have been shown to be effective for a variety of hydroalkoxycarbonylation protocols [45][46][47][48][49]. In this regard, in a previous paper, some of the authors have studied the effectiveness of AlCl 3 as substitute of the p-toluenesulfonic acid (TsOH) in the hydroethoxycarbonylation of 1-olefins [48][49][50][51].…”