Amine induced carbonylation of alkynes to cyclobutenediones using Fe3(CO)12

Iron carbonyl species, prepared in situ in THF using Fe3(CO)12, react with alkynes at 25°C, in the presence of certain amines, to give the corresponding cyclobutenediones in moderate to good yields (25–61%) after CuCl2·2H2O oxidation.