% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@INPROCEEDINGS{Omrane:866645,
      author       = {Omrane, Aymen and Zlatopolskiy, Boris and Neumaier, Bernd},
      title        = {2‐[18{F}]{F}luoro‐5‐iodopyridine ([18{F}]{FIP}y): {A}
                      novel reactive prosthetic group for the fast site specific
                      radiolabeling via {P}d‐catalyzed cross coupling reactions},
      reportid     = {FZJ-2019-05724},
      year         = {2019},
      abstract     = {Aim: Numerous Pd‐catalyzed cross‐couplings like
                      Sonogashira, Suzuki‐Miyaura, Heck, and Stille reactions
                      proved to be valuable tools for the site specific labeling
                      of biopolymers. The aim of this work was the study of
                      Pd‐catalyzed cross coupling reactions using [18F]FIPy as
                      radiolabeled synthon and
                      2,2′‐(1,2‐phenylene)‐bis‐(4,4‐dimethyl‐4,5‐dihydrooxazole)‐N,N′‐palladium
                      dichloride (Pd‐BOX‐1) as catalyst. Pd‐BOX‐1
                      demonstrated exceptional air and moisture stability and
                      excellent catalytic activity in aqueous reaction media.
                      MethodsThe direct reaction of 2‐bromo‐5‐iodopyridine
                      with DABCO followed by anion metathesis using TMSOTf
                      afforded
                      1‐(5‐iodopyridin‐2‐yl)‐1,4‐diazabicyclo[2.2.2]octan‐1‐ium
                      triflate (1) used as precursor for the preparation of
                      [18F]FIPy. The latter was produced using the
                      “minimalist” protocol. Accordingly, [18F]fluoride was
                      eluted from a QMA cartridge with a solution of 1 in MeOH.
                      MeOH was evaporated at 45°C (250 mbar) within 4 min, DMSO
                      was added, and the resulting solution was heated affording
                      [18F]FIPy, which after the purification by SPE was
                      conjugated to different model compounds by different
                      Pd‐catalyzed $(1\%$ of Pd‐BOX‐1) cross‐couplings
                      using aqueous MeCN or DMF as reaction solvent within 10 min.
                      Results18F– recovery from an anion exchange resin using 1
                      (3 mg) amounted $>98\%.$ Heating of the resulting
                      [18F]fluoride onium salt in DMSO at 100°C for 15 min
                      afforded [18F]FIPy in excellent radiochemical conversions
                      (RCCs) of 91 ± $3\%.$ [18F]FIPy was isolated in 61 ± $5\%$
                      radiochemical yield (RCY) and excellent radiochemical purity
                      (RCP) of $>98\%.$ The subsequent Cu and phosphine free
                      Pd‐BOX‐1 catalyzed Sonogashira cross‐coupling with
                      phenylacetylene afforded the corresponding conjugate in an
                      excellent RCC of $>89\%.$ Furthermore, Suzuki‐Miyaura,
                      Heck, and Stille reactions with 4‐methylphenyl boronic
                      acid, methyl acrylate, and trimethyl (phenyl)tin,
                      respectively, applied as model coupling partners furnished
                      the corresponding radiofluorinated conjugates in RCCs of
                      $85–98\%.$ Conclusion[18F]FIPy is a valuable radiolabeled
                      prosthetic group easily accessible using the
                      “minimalist” approach. Various Pd‐BOX‐1‐catalyzed
                      cross coupling reactions with [18F]FIPy is a versatile
                      procedure for a fast, high‐yielding, and site specific
                      radiolabeling under relatively mild conditions.},
      month         = {May},
      date          = {2019-05-26},
      organization  = {The 23rd International Symposium on
                       Radiopharmaceutical Sciences, Beijing
                       (China), 26 May 2019 - 31 May 2019},
      subtyp        = {After Call},
      cin          = {INM-5},
      cid          = {I:(DE-Juel1)INM-5-20090406},
      pnm          = {573 - Neuroimaging (POF3-573)},
      pid          = {G:(DE-HGF)POF3-573},
      typ          = {PUB:(DE-HGF)6},
      url          = {https://juser.fz-juelich.de/record/866645},
}