Palladium-Catalyzed Allylation of Polyfluoroarenes with Allylic PivalatesThis work was supported by the National Natural Science Foundation of China (NSFC) (grants numbers 21676252 and 21506191).
Received: 04 July 2017
Accepted after revision: 03 September 2017
19 September 2017 (eFirst)
An efficient 1,5-cyclooctadiene–PdCl2/dicyclohexyl(2′,4′,6′-triisopropylbiphenyl-2-yl)phosphine (XPhos) catalytic system was developed for C–H allylation of polyfluoroarenes with allylic pivalates. The reactions showed excellent functional-group tolerance, good yields, and high regioselectivities. Mechanistic investigations supported a (π-allyl)palladium complex pathway through a directed oxidative addition of the allylic pivalate to palladium, followed by sequential nucleophilic attack by the polyfluorobenzene and reductive elimination. In a gram-scale reaction, a palladium loading of 0.5 mol% was enough to afford the required product in good yield.