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Photoinitiated Oxidative Addition of CF(3)I to Gold(I) and Facile Aryl-CF(3) Reductive Elimination

[Image: see text] Herein we report the mechanism of oxidative addition of CF(3)I to Au(I), and remarkably fast C(aryl)–CF(3) bond reductive elimination from Au(III) cations. CF(3)I undergoes a fast, formal oxidative addition to R(3)PAuR′ (R = Cy, R′ = 3,5-F(2)-C(6)H(4), 4-F-C(6)H(4), C(6)H(5), 4-Me-...

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Detalles Bibliográficos
Autores principales: Winston, Matthew S., Wolf, William J., Toste, F. Dean
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2014
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4046758/
https://www.ncbi.nlm.nih.gov/pubmed/24836526
http://dx.doi.org/10.1021/ja503974x
Descripción
Sumario:[Image: see text] Herein we report the mechanism of oxidative addition of CF(3)I to Au(I), and remarkably fast C(aryl)–CF(3) bond reductive elimination from Au(III) cations. CF(3)I undergoes a fast, formal oxidative addition to R(3)PAuR′ (R = Cy, R′ = 3,5-F(2)-C(6)H(4), 4-F-C(6)H(4), C(6)H(5), 4-Me-C(6)H(4), 4-MeO-C(6)H(4), Me; R = Ph, R′ = 4-F-C(6)H(4), 4-Me-C(6)H(4)). When R′ = aryl, complexes of the type R(3)PAu(aryl)(CF(3))I can be isolated and characterized. Mechanistic studies suggest that near-ultraviolet light (λ(max) = 313 nm) photoinitiates a radical chain reaction by exciting CF(3)I. Complexes supported by PPh(3) undergo reversible phosphine dissociation at 110 °C to generate a three-coordinate intermediate that undergoes slow reductive elimination. These processes are quantitative and heavily favor C(aryl)–I reductive elimination over C(aryl)–CF(3) reductive elimination. Silver-mediated halide abstraction from all complexes of the type R(3)PAu(aryl)(CF(3))I results in quantitative formation of Ar–CF(3) in less than 1 min at temperatures as low as −10 °C.