Lipase-catalyzed synthesis of carboxylic amides: Nitrogen nucleophiles as acyl acceptor

The lipase-catalyzed aminolysis of carboxylic esters is a fairly general re action that has been performed with a wide range of esters and amines, gene rally in anhydrous organic media to avoid undesirable hydrolysis of the est er. Alternatively, carboxylic amides can be synthesized by lipase mediated condensation of carboxylic acids and amines if an excess of either reactant is avoided. Chiral carboxylic esters have been resolved by lipase-catalyzed aminolysis. In the majority of these resolutions, Candida antarctica lipase B has been employed as the catalyst. A range of chiral amines has been resolved by li pase mediated acylation, using mainly the lipases from C. antarctica (B typ e) and Pseudomonas species. The enantiorecognition was frequently found to depend critically on the acylating agent and the reaction medium.