A combination of experimental and density functional theory (DFT) investigations suggests that the Cu-catalyzed fluorination of unsymmetrical diaryliodonium salts with general structure [Mes(Ar)I]⁺ in N,N′-dimethylformamide proceeds through a Cu^I/Cu^III catalytic cycle. A low concentration of fluoride relative to combined iodonium reagent plus copper ensures that [Mes(Ar)I]⁺ is available as the reactive species for oxidative "Ar⁺" transfer to a Cu^I center containing one or two fluoride ligands. A series of different possible Cu^I active catalysts (containing fluoride, triflate, and DMF ligands) have been evaluated computationally, and all show low-energy pathways to fluorinated products. The oxidation of these Cu^I species by [Mes(Ar)I]⁺ to form cis-Ar(F)Cu^III intermediates is proposed to be rate-limiting in all cases. Ar–F bond-forming reductive elimination from Cu^III is computed to be very facile in all of the systems examined. The conclusions of the DFT experiments are supported by several experimental studies, including tests showing that Cu^I is formed rapidly under the reaction conditions and that the fluoride concentration strongly impacts the reaction yields/selectivities.

Item Type:	Refereed Article
Keywords:	copper catalysis, iodonium
Research Division:	Chemical Sciences
Research Group:	Inorganic chemistry
Research Field:	Organometallic chemistry
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the chemical sciences
UTAS Author:	Canty, AJ (Professor Allan Canty)
UTAS Author:	Yates, BF (Professor Brian Yates)
ID Code:	97173
Year Published:	2014
Web of Science® Times Cited:	52
Deposited By:	Chemistry
Deposited On:	2014-12-05
Last Modified:	2017-10-25
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