Biocatalytic Approaches to Amide Synthesis

Although amide bonds are among the most ubiquitous functional groups found within organic molecules, traditionalchemical methods of amide synthesis present a number of shortcomings. Enzymes, which typically exhibit high selectivityand function under benign conditions in aqueous media, can address some of the issues encountered with chemicalsynthesis of amides. Early approaches to biocatalytic amide synthesis employed hydrolase enzymes such as lipases, esterases,acylases or proteases operating in the reverse synthetic direction often requiring organic solvents. However, in recent yearspowerful ATP-dependent ligases have been discovered, engineered and deployed for amide assembly. In this review we willdiscuss the advantages and disadvantages of the different biocatalysts available for amide synthesis, from hydrolases andnitrile hydratases, through to amide bond synthetase (ABS), ATP-grasp and other specialized ligase enzymes