Catalysis by Pincer Complexes: Synthesis of Esters, Amides, and Peptides

Esters, amides, and peptides are important fine and bulk chemicals. Development of new green catalytic reactions for the synthesis of these products is highly desirable. Pincer complexes, particularly those that operate by "metal-ligand cooperation" involving aromatization-dearomatization of ligand motifs exhibit remarkable catalytic efficiency in the synthesis of these products from fundamental feedstocks such as alcohols, amines, and aminoalcohols. Gratifyingly, a range of useful products, including polyesters and polyamides, were efficiently prepared by the newly developed catalytic methods. These catalytic reactions proceed selectively under neutral, mild conditions, do not generate waste, and provide dihydrogen, which is valuable by itself.