DUGi

Nucleophilic Aryl Fluorination and Aryl Halide Exchange Mediated by a CuI/CuIII Catalytic Cycle

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@7129

Copper-catalyzed halide exchange reactions under very mild reaction conditions are described for the first time using a family of model aryl halide substrates. All combinations of halide exchange (I, Br, Cl, F) are observed using catalytic amounts of CuI. Strikingly, quantitative fluorination of aryl–X substrates is also achieved catalytically at room temperature, using common F– sources, via the intermediacy of aryl–CuIII–X species. Experimental and computational data support a redox CuI/CuIII catalytic cycle involving aryl–X oxidative addition at the CuI center, followed by halide exchange and reductive elimination steps. Additionally, defluorination of the aryl–F model system can be also achieved with CuI at room temperature operating under a CuI/CuIII redox pai

We thank Prof. S. S. Stahl (Univ. of Wisconsin, Madison, WI) for fruitful comments and for early experiments conducted by A.C. in Stahl’s lab. We acknowledge financial support from MICINN of Spain (CTQ2009-08464/BQU to M.C., CTQ2008-03077/BQU and CTQ2011-23156/BQU to M.S., Consolider-Ingenio CSD2010-00065, and Ph.D. grant to A.C.), European Research Council for Project ERC-2011-StG-277801 and the Catalan DIUE of the Generalitat de Catalunya (2009SGR637 to M.S., and a Ph.D. grant to M. Canta). X.R, MC., and MS. thank ICREA-Academia awards. We thank STR’s from UdG for technical support, and we also acknowledge the Centre de Serveis Cientifics i Academics de Catalunya (CESCA) for partial funding of computer time

American Chemical Society