Direct and chlorine-free synthesis of phosphafluorenes or their oxides from white phosphorus

Abstract

The known methods for the preparation of acylphosphine oxides and polyfluorobenzene-substituted triarylphosphines need to utilize PCl3, while the chlorine-free methods are not reported. In this work, we report a chlorine-free method by one-pot three-component reaction of white phosphorus (P4), dilithio reagents, and acyl chlorines or polyfluorobenzenes for the synthesis of biphenyl-based acylphosphine oxides and phosphines. This reaction is green and environmentally friendly compared with the traditional method, because it avoids the use of Cl2 and the discharge of a large amount of waste gas and waste acid. These two products have potential applications as photoinitiators in photopolymerization or as organophosphorus ligands in catalytic reactions.