Biocatalytic Aldol Reaction of Cyclohexanone Catalyzed by Artificial Enzyme

• 1、School of Life Sciences and Health Engineering, Jiangnan University,Wuxi 214122

Abstract：The aldol reaction of cyclohexanone catalyzed by an artificial enzyme via the enamine mechanism was investigated. The aldol reaction involves the nucleophilic addition of enolate anions to aldehydes or ketones, representing one of the key reactions in organic chemistry for forming carbon-carbon bonds. In this study, an artificial enzyme incorporating secondary amine catalytic groups was designed via a protein covalent linking strategy. This artificial enzyme activated the carbonyl group through the enamine mechanism, catalyzed the formation of nucleophilic enamine intermediates with cyclohexanone, and facilitated the aldol reaction between cyclohexanone and indole quinone. Reaction conditions were systematically optimized according to the characteristics of the target reaction, and it was confirmed that the artificial enzyme successfully catalyzed the reaction under optimized conditions. The reaction results were validated using high-performance liquid chromatography (HPLC). Although the stereoselectivity and yield of the current reaction have yet to reach ideal levels, this study demonstrates the potential of artificial enzymes to catalyze aldol condensation reactions involving cycloketone molecules. Furthermore, it provides a theoretical basis for the design of artificial enzymes and the development of unnatural catalytic functions.?????

Keywords： Artificial enzymes, Biocatalysis,Covalent conjugation,Aldol reaction, Biosynthesis