Copper-Catalyzed Direct Twofold C–P Cross-Coupling of Unprotected Propargylic 1,4-Diols: Access to 2,3-Bis(diarylphosphynyl)-1,3-butadienes

The first facile and efficient Cu-catalyzed direct coupling of unprotected propargylic diols with H -phosphine oxides was developed, providing a practical approach to access structurally diverse 2,3-bis(diarylphosphynyl)-1,3-butadienes along with the formation of two new P–C sp 2 and two new C═C bonds under ligand- and base-free conditions.