Copper/iron-catalyzed Ullmann coupling of diiodo- and dibromoarenes and diphenols for the synthesis of aryl ether macrocycles

Diiodoarenes (or dibromoarenes) reacted with diphenols, catalyzed by CuI/Fe(acac)3 in the presence of K2CO3 in anhydrous DMSO at 110 °C for 7 days under nitrogen atmosphere, to afford macrocyclic aryl ethers effectively. To expand this methodology, a cyclic hepta(p-phenylene oxide) and cyclic deca(p-phenylene oxide) were synthesized in one pot. Some macrocyclic aryl ethers showed strong fluorescence in acetone at 25 °C.