Copper-Catalyzed Arylation of Heterocycle C—H Bonds.

The article examines the effect of copper salts on the regioselectivity of palladium-catalyzed electron-rich heterocycle arylation. The said effect may arise from the involvement of organocopper intermediates in the reaction and this presumed intermediate can generate without a palladium cocatalyst that will become a cheap and efficient method for heterocycle arylation. Moreover, the best results were obtained by using a combination of lithium t-butoxide base aryl iodide coupling partner.