Mechanistic Investigations of Cu-Catalyzed Fluorination of Diaryliodonium Salts: Elaborating the Cu(I)/Cu(III) Manifold in Copper Catalysis.
Mechanistic Investigations of Cu-Catalyzed Fluorination of Diaryliodonium Salts: Elaborating the Cu(I)/Cu(III) Manifold in Copper Catalysis.
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DOI：
10.1021/om5007903
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发表时间：
2014-10-13
期刊：
影响因子：
2.8
通讯作者：
Sanford MS
中科院分区：
文献类型：
--
作者：
Ichiishi N;Canty AJ;Yates BF;Sanford MS
结合实验和密度泛函理论（DFT）研究表明，具有一般结构[Mes(Ar)I]+的不对称二芳硫鎓盐在N，N ' -二甲基甲酰胺中的cu催化氟化是通过CuI/CuIII催化循环进行的。相对于碘试剂加铜的组合，低浓度的氟化物确保了[Mes(Ar)I]+可以作为氧化“Ar+”转移到含有一个或两个氟配体的CuI中心的反应物质。一系列不同的可能的CuI活性催化剂（含氟、三氟酸盐和DMF配体）已经被计算评估，并且都显示出低能途径氟化产物。这些CuI被[Mes(Ar)I]+氧化形成顺式Ar(F)CuIII中间体被认为在所有情况下都是限速的。经计算，在所有所研究的体系中，由CuIII形成的Ar-F键的还原消除是非常容易的。DFT实验的结论得到了几项实验研究的支持，其中包括在反应条件下快速形成CuI以及氟浓度对反应产率/选择性有强烈影响的实验。
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 CuI/CuIII 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 CuI center containing one or two fluoride ligands. A series of different possible CuI 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 CuI species by [Mes(Ar)I]+ to form cis-Ar(F)CuIII intermediates is proposed to be rate-limiting in all cases. Ar–F bond-forming reductive elimination from CuIII 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 CuI is formed rapidly under the reaction conditions and that the fluoride concentration strongly impacts the reaction yields/selectivities.
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影响因子：
2.8
作者：
Canty, Allan J.;Ariafard, Alireza;Yates, Brian F.
通讯作者：
Yates, Brian F.
影响因子：
4.3
作者：
Baralle, Alexandre;Fensterbank, Louis;Ollivier, Cyril
通讯作者：
Ollivier, Cyril
影响因子：
16.6
作者：
Duong, Hung A.;Gilligan, Ruth E.;Gaunt, Matthew J.
通讯作者：
Gaunt, Matthew J.
影响因子：
3.3
作者：
Landrum, GA;Goldberg, N;Minyaev, RM
通讯作者：
Minyaev, RM
影响因子：
5.2
作者：
Ichiishi, Naoko;Brooks, Allen F.;Topczewski, Joseph J.;Rodnick, Melissa E.;Sanford, Melanie S.;Scott, Peter J. H.
通讯作者：
Scott, Peter J. H.