The Construction of Furocoumarins through Iron-Catalyzed Relay Annulation of Oxime Esters with 4-Hydroxycoumarins

An iron-catalyzed relay annulation protocol was disclosed, which utilizes oxime esters and 4-hydroxycoumarins as the readily available starting materials and showcases broad substrate scope and good functional group tolerance. This method allows the simultaneous generation of two C–C and one C–O bonds and two rings in one step, affording structurally new furocoumarins in moderate to good yields.