Applications of Nucleophilic Fluorine Sources in the Selective Fluorofunctionalization of Unsaturated Carbon-Carbon Bonds

Multi-substituted trifluoromethyl alkene construction via gold-catalyzed fluoroarylation of gem-difluoroallenes

“…[27][28][29] In the context, the Witting-type olenation [30][31][32] and transition-metalcatalyzed cross-coupling reactions 26,27,[33][34][35] evolve to be the state of the art, despite the remaining issues such as strongly basic reaction conditions, volatile and expensive tri-uoromethyl reagents, and poor stereoselectivities. With our continuing interest in the uoroarylation of p systems, 15,21,36,37 we would like to report herein our latest advancement in this territory (Scheme 1d). Notable features include: (i) the coordination of the allene motif by the in situ generated trivalent gold complex not only prompts the nucleophilic uorination via substrate activation, but more importantly induces a cascade which eventually affords the triuoromethyl alkene with high stereoselectivity; (ii) the uoroarylation is subjected to a chargecontrolled scenario, by which the nucleophilic attack of uoride selectively targets the a-carbon atom, while the formation of the triuoromethyl in turn permits a thermodynamic driving force for such a step.…”