Photocatalyzed cascade oxidative annulation of propargylamines and phosphine oxides

Chem Commun (Camb). 2017 Jun 16;53(49):6637-6640. doi: 10.1039/c7cc02433a.

Abstract

On account of the broad utilities of organophosphorus compounds, the development of highly efficient and concise phosphination methods is significantly important and urgent. Herein, we disclose a novel method for the synthesis of phosphorylated heterocycles: versatile intermediate propargylamines serving as a new type of radical acceptors incorporated in P-radicals via a photocatalytic strategy. This reaction proceeds through a cascade phosphinoylation/cyclization/oxidation/aromatization pathway using readily available starting materials under mild conditions of light with excellent atom economy, catalyzed by AgOAc or fac-Ir(ppy)3. One of the phosphorylated quinolines was selected, as an example, as an electron-transporting material for fabricating phosphorescence organic light-emitting diodes displaying excellent electroluminescence performances with a maximum external quantum efficiency of 21.9% with negligible efficiency roll-off ratios.