Rhenium-catalyzed insertion of terminal acetylenes into a C-H bond of active methylene compounds

[GRAPHICS] A rhenium complex, [ReBr(CO)(3)(thf)](2), Catalyzed the intermolecular reactions of 1,3-dicarbonyl compounds with terminal acetylenes and gave the corresponding alkenyl derivatives in excellent yields. These reactions could apply to an intramolecular version and gave the corresponding cyclic compounds quantitatively.