The amine as carbonyl precursor in the chemoenzymatic synthesis of Passerini adducts in aqueous medium

A new simple environmentally friendly protocol based on sequential chemoenzymatic synthesis of alpha-acyloxy carboxyamides from amines as a carbonyl precursor is presented. For the synthesis of the desired products, biocatalytic process combining laccase/TEMPO oxidation of amine followed by Passerini reaction was developed. After a careful optimization of the reaction conditions only one of desired Passerini reaction products was obtained despite of the presence of two different carboxylic acids in reaction medium. The developed protocol offers a chemoselective and environmentally friendly procedure for the synthesis of various alpha-acyloxy amides with good to excellent yields.