Copper‐Catalyzed Cascade Cyclization of 2‐Propynolphenols: Access to 4‐Phosphorylated 2H‐Chromenes

A novel copper‐catalyzed cascade cyclization of easily prepared 2‐propynolphenols with disubstituted phosphine oxides has been developed to give 4‐phosphorylated 2 H ‐chromenes in moderate to excellent yields. This cascade process involves multiple bond‐forming events including C–O and C–P bonds. Moreover, both tertiary and secondary propargylic alcohols with diverse functional groups showed excellent compatibilities under ligand‐ and additive‐free conditions. magnified image