Highly regioselective cobalt-catalyzed [2+2+2] cycloaddition of fluorine-containing internal alkynes to construct various fluoroalkylated benzene derivatives

Novel cobalt-catalyzed [2 + 2 + 2] cycloaddition using fluorine-containing alkynes was described. Cyclotrimerization of fluorinated alkynes under the influence of CoCl2(dppb) in acetonitrile at 80 degrees C for 3 h took place smoothly, affording the corresponding benzene derivatives in excellent yields with high regioselectivity. Additionally, intermolecular cycloaddition of fluorinated alkynes with non-fluorinated diynes also proceeded in the presence of a catalytic amount of CoCl2((S)-BINAP) and ZnI2 to give various bicyclic aromatic compounds in high yields.