Functionalized phosphine ligands in transition metal-catalysed organic synthesis. Nickel(0)-catalysed cycloaddition of terminally unsubstituted diynes and carbon dioxide to bicyclic 2-pyrones

Abstract

A functionalized trialkylphosphine ligand (1a) containing a pyridyl group has effected the Ni(0)-catalysed cycloaddition of terminally unsubstituted diynes with CO₂ to give bicyclic 2-pyrones, for which ordinary trialkylphosphine ligands are not effective.