Selective reductive defluorination of dicyclohexyl compounds: Intramolecular coupling reaction by reductive cleavage of C-F bonds

Reductive defluorination of perfluoro(dicyclohexyl ether) 1 with benzophenone anion radical in tetrahydrofuran produces perfluoro(dibenzofuran) 2 with a surprising ring-closure, whereas reductive defluorination of perfluoro(dicyclohexyl) 4 under the same conditions gives perfluoro(diphenyl) 6 with no products involving ring-closure.