Zinc Chloride-Promoted Coupling Reaction between Calcium Carbide and Aryl Chlorides

The direct synthesis of diarylethynes from less-reactive aryl chlorides and calcium carbide was accomplished by palladium catalysis. The coupling reaction is provided with broad substrate scope, the use of ZnCl2 as cocatalyst, and the use of safe, inexpensive and easy to handle acetylene source, and provided the desired 1,2-Bis(9-anthryl)acetylene, even when being highly sterically hindered.

Automated summary

The direct synthesis of diarylethynes from less-reactive aryl chlorides and calcium carbide was achieved by palladium catalysis. The coupling reaction showed a broad substrate scope and could be applied to highly sterically hindered reaction systems.