Development of Efficient Ru/Deep Eutectic Solvent Catalytic System for Alkoxycarbonylation of Alkene without Acid Additives

Abstract The catalytic alkoxycarbonylation of alkenes is an attractive, atom‐efficient method for producing value‐added carboxylic esters. However, the conventional catalyst system for this reaction needs coordination with a noble metal, sensitive ligands and proton acid additives. Therefore, the design of a simple and efficient catalyst system without any acid additives under mild conditions is still a major challenge. In this work, a simple ruthenium/deep eutectic solvent catalytic system was developed to effectively catalyse the alkoxycarbonylation reaction without any sensitive ligands or acid additives under mild conditions. The conversion of 1‐hexene reached 99.0 %, and the ester selectivity was 99.1 %, much higher than that of Ruthenium carbonyl without deep eutectic solvent. The excellent performance of the catalytic system could be ascribed to the form of the ruthenium active species [Ru(CO) 2 Br 3 ] − in the deep eutectic solvent. This innovative catalyst system presents a significant advancement in the alkoxycarbonylation reaction, eliminating the use of acid additives and delicate ligands.