Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Jun 5;10(30):7251-7259.
doi: 10.1039/c9sc02162k. eCollection 2019 Aug 14.

Substituent-controlled, mild oxidative fluorination of iodoarenes: synthesis and structural study of aryl I(iii)- and I(v)-fluorides

Joel Häfliger  1 , Cody Ross Pitts  1 , Dustin Bornemann  1 , Roland Käser  1 , Nico Santschi  1 , Julie Charpentier  1 , Elisabeth Otth  1 , Nils Trapp  1 , René Verel  1 , Hans Peter Lüthi  1 , Antonio Togni  1
Affiliations

Substituent-controlled, mild oxidative fluorination of iodoarenes: synthesis and structural study of aryl I(iii)- and I(v)-fluorides

Joel Häfliger et al. Chem Sci. .

Abstract

We report a mild approach to the synthesis of difluoro(aryl)-λ3-iodanes (aryl-IF2 compounds) and tetrafluoro(aryl)-λ5-iodanes (aryl-IF4 compounds) using trichloroisocyanuric acid (TCICA) and potassium fluoride (KF). Under these reaction conditions, selective access to either the I(iii)- or I(v)-derivatives is predictable based solely on the substitution pattern of the iodoarene starting material. Moreover, the discovery of this TCICA/KF approach prompted detailed dynamic NMR, kinetic, computational, and crystallographic studies on the relationship between the IF2 group and the ortho-substituents on carefully designed probe molecules. It was during these experiments that the role of the ortho-substituent in inhibiting further oxidative fluorination of I(iii)-compounds to I(v)-compounds during the reaction with TCICA and KF was revealed. Additionally, a notable exception to this empirical trend is discussed herein.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1. Mild and predictable access to aryl-IF2 and aryl-IF4 compounds based on iodoarene substitution pattern.
Fig. 2
Fig. 2. (Top panel) Probe molecules used to investigate rotation of IF2 moiety about C–I bond via VT-NMR. (Bottom panel) Highlighting design features of probe molecule 21.
Fig. 3
Fig. 3. Stacked 19F NMR spectra of the IF2 signal in probe molecule 21 over a range of temperatures from 298 K to 168 K. A zoomed-in spectrum is displayed for the coalescence temperature (TC) at 228 K.
Fig. 4
Fig. 4. Isodesmic relationship at wB97xD/cc-pvdz (cc-pvdz-PP for the iodine atom).
Fig. 5
Fig. 5. Crystal structure of compound 21 determined from single-crystal X-ray diffraction (displacement ellipsoids depicted at 50% probability level).
Fig. 6
Fig. 6. Crystal structure of compound 26 determined from single-crystal X-ray diffraction (displacement ellipsoids depicted at 50% probability level).
Fig. 7
Fig. 7. Extended application to the synthesis of an ortho-substituted I(v) compound (37) as an exception to the rule. Yield determined by 19F NMR.
Fig. 8
Fig. 8. Crystal structure of compound 37 determined from single-crystal X-ray diffraction (displacement ellipsoids depicted at 50% probability level, only one of two asymmetric moieties from asymmetric unit shown).
See this image and copyright information in PMC

References

    1. Zhdankin V. V., Hypervalent Iodine Chemistry: Preparation, Structure and Synthetic Applications of Polyvalent Iodine Compounds, John Wiley & Sons, West Sussex, UK, 2014.
    1. Ye C., Twamley B., Shreeve J. M. Org. Lett. 2005;7:3961. - PubMed
    1. Sarie J. C., Thiehoff C., Mudd R. J., Daniliuc C. G., Kehr G., Gilmour R. J. Org. Chem. 2017;82:11792. - PubMed

    1. For reviews, see:

    2. Stang P. J., Zhdankin V. V. Chem. Rev. 1996;96:1123. - PubMed
    3. Zhdankin V. V. ARKIVOC. 2009:1.
    4. Yoshimura A., Zhdankin V. V. Chem. Rev. 2016;116:3328. - PubMed

    1. For some examples, see:

    2. Zupan M., Pollak A. J. Fluorine Chem. 1976;7:445.
    3. Ruppert I. J. Fluorine Chem. 1980;15:173.
    4. Naumann D., Rüther G. J. Fluorine Chem. 1980;15:213.
    5. Alam K., Janzen A. F. J. Fluorine Chem. 1987;36:179.
    6. Hara S., Yoshida M., Fukuhara T., Yoneda N. Chem. Commun. 1998:965.
    7. Padelidakis V., Tyrra W., Naumann D. J. Fluorine Chem. 1999;99:9.
    8. Frohn H. J., Bardin V. V. J. Fluorine Chem. 2005;126:1036.
    9. Ye C., Twamley B., Shreeve J. M. Org. Lett. 2005;7:3961. - PubMed
    10. Suzuki S., Kamo T., Fukushi K., Hiramatsu T., Tokunaga E., Dohi T., Kita Y., Shibata N. Chem. Sci. 2014;5:2754.
    11. Banik S. M., Medley J. W., Jacobsen E. N. J. Am. Chem. Soc. 2016;138:5000. - PMC - PubMed
    12. Haupt J. D., Berger M., Waldvogel S. R. Org. Lett. 2019;21:242. - PubMed