Lipase-Catalyzed Esterification of Protected Amides under Ultrasound Irradiation via N–C(O) Cleavage

Abstract A novel ultrasound-assisted protocol has been devised for the highly chemoselective esterification of tert-butyloxycarbonyl (Boc)-activated secondary carboxamides with alcohols. This study highlights the catalytic versatility of PPL lipase, which extends beyond their traditional hydrolytic functions to include synthetic applications like esterification and transesterification. The research investigates the enzymatic esterification of protected amides with alcohols, utilizing PPL lipase as a biocatalyst under ultrasound irradiation. This method can achieve high reaction rates and selectivities under mild conditions.