Reactivity of Para-Substituted Fluorobenzenes in Palladium-catalyzed Intermolecular Direct Arylations

International audienceThe influence of both electron-withdrawing and electron-donating substituents such as amino, bromo, chloro, ketone, methyl, methoxy, and nitro at C-4 on fluorobenzene derivatives, for palladium-catalyzed direct arylation at α-position to the fluorine atom has been explored. With moderate electron-withdrawing substituents, the reaction proceeds nicely using phosphine-free PdCl2 catalyst, at a very low loading, and potassium pivalate/dimethylacetamide (PivOK/DMA) as catalytic system. In all cases, a regioselective arylation at the α position to the fluorine atom was observed. Moreover, a wide variety of substituents on the aryl bromide coupling partner, such as formyl, nitro, nitrile, chloro, and methyl, and also heteroaryl bromides was tolerate