Synthesis of (Z)-2-[(Z)-3-alkylideneisobenzofuran-1(3H)-ylidene]acetic acid derivatives by sequential coupling-cyclization between 3-(2-iodophenyl)-3- oxopropanoic acid derivatives and terminal alkynes
3-(2-Iodophenyl)-3-oxopropanoic acid derivatives reacted efficiently with various terminal alkynes in the presence of catalytic amounts of dichlorobis(triphenylphosphine)palladium and copper(I) iodide and two molar amounts of triethylamine in N,N-dimethyl