Direct synthesis of adipic acid esters via palladium-catalyzed carbonylation of 1,3-dienes

A carbonylation path to a nylon precursor Adipic acid and its esters are manufactured on a massive scale, primarily to produce nylon. However, the standard route requires large quantities of corrosive nitric acid. J. Yang et al. present an efficient alternative route whereby a palladium catalyst adds carbon monoxide to each end of butadiene (see the Perspective by Schaub). Both reactants are available at commodity scale, and the reaction produces no by-products. An optimized bidentate phosphine ligand bearing a pyridine substituent for proton shuttling proved key to attaining the necessary selectivity. Science , this issue p. 1514 ; see also p. 1447