180293-26-9Relevant academic research and scientific papers
Constructing a catalytic cycle for c-f to c-x (x = o, s, n) bond transformation based on gold-mediated ligand nucleophilic attack
Hu, Ji-Yun,Zhang, Jing,Wang, Gao-Xiang,Sun, Hao-Ling,Zhang, Jun-Long
supporting information, p. 2274 - 2283 (2017/01/16)
A tricoordinated gold(I) chloride complex, tBuXantphosAuCl, supported by a sterically bulky 9,9-dimethyl-4,5-bis(di-Tert-butylphosphino)xanthene ligand (tBuXantphos) was synthesized. This complex features a remarkably longer Au?Cl bond length [2.632(1) ?] than bicoordinated linear gold complexes (2.27-2.30 ?) and tricoordinated XantphosAuCl [2.462(1) ?]. Single-crystal Xray diffraction analysis of a cocrystal of tBuXantphosAuCl and pentafluoronitrobenzene (PFNB) and UV-vis spectroscopic titration experiments revealed the existence of an anion-φ interaction between the Cl anion ligand and PFNB. Stoichiometric reaction between PFNB and tBuXantphosAuOtBu, after replacement of Cl by a more nucleophilic tBuO anion ligand, showed higher reactivity and para selectivity in the transformation of C-F to C-OtBu bond, distinctively different from that when only KOtBu was used (ortho selectivity) under the identical condition. Mechanistic studies including density functional theory calculations suggested a gold-mediated nucleophilic ligand attack of the C?F bond pathway via an SNAr process. On the basis of these results, using trimethylsilyl derivatives TMS-X (X = OMe, SEt, NEt) as the nucleophilic ligand source and the fluorine acceptor, catalytic transformation of the C-F bond of aromatic substrates to the C-X (X = O, S, N) bond was achieved with tBuXantphosAuCl as the catalyst (up to 20 turnover numbers).
The photochemistry of various para-substituted tetrafluorophenyl azides in acidic media and the formation of nitrenium ions
Michalak, Jacek,Zhai, Hong Bin,Platz, Matthew S.
, p. 14028 - 14036 (2007/10/03)
Laser flash photolysis of polyfluorinated aryl azides in acetonitrile at ambient temperature produces singlet nitrenes which have lifetimes of tens to hundreds of nanoseconds. The lifetimes are controlled by ring expansion and intersystem crossing to the
