An efficient method for the synthesis of 3,5-disubstituted pyrazoles is described. The reactions of 1,3-dialkynes with hydrazine proceeded smoothly in dimethyl sulfoxide under mild reaction conditions to produce 3,5-disubstituted pyrazoles in satisfactory to excellent yields. A one-pot procedure of the transformation has been developed.

An efficient method for the synthesis of 3,5-disubstituted isoxazoles is described. The reactions of 1,3-dialkynes with hydroxylamine proceeded smoothly in DMSO under mild reaction conditions to produce 3,5-disubstituted isoxazoles in satisfactory to excellent yields.

Palladium-catalyzed carbonylative addition of aryl bromides to terminal arylalkynes was carried out to produce chalcones in satisfactory to excellent yields. The unprecedented carbonylation reaction proceeded smoothly under mild conditions in the presence of a simple palladium catalyst system (PdCl2/DPPB/(i)Pr2NEt) in N,N-dimethyl formamide.