Fluorine Radiochemistry

Challenges in radiochemistry with short-lived positron emitters, including fluorine-18... 

From a chemical point of view, the half-life of fluorine-18 allows multi-step synthetic approaches that can be extended over hours. Fluorine-18 has therefore, in spite of its somewhat limited chemical repertoire, been effectively used for the labelling of numerous both relatively simple and complex bioactive chemical structures [3,5-9], including high-molecular-weight macromolecules such as peptides, proteins [10-13] and oligonucleotides [14-18]. General considerations on radiochemistry involving short-lived positron emitters will be discussed in Section 2.3. 

Cady, G. H. Fluorine-Containing Compounds of Sulfur, in Emeleus and Sharpe s Advances in Inorganic Chemistry and Radiochemistry, Yol. II, 105-158, Academic Press Inc., New York (1960). 

In 1982, a comprehensive review by Fowler and Wolf listed 88 fluorine-18 radiochemicals [1] by 1990, a subsequent review [2] had listed over 280 compounds in a similar table, and although there are no more recent attempts to compile a comprehensive listing of such radiochemicals, at the most recent International Symposium on Radiopharmaceutical Chemistry, there were over 140 individual abstracts involving fluorine-18 alone [3], indicative of the continued growth in the field of fluorine-18 radiochemistry. A few recent reviews are available for fluorine-18 radiopharmaceuticals [4-9], and the reader is directed to modem literature-searching methods to obtain a more complete listing of currently available radiochemicals. 

In the field of radiochemistry, and particularly with the use of high-specific-activity radionuclides, syntheses are almost uniformly done with an excess of unlabeled precursor and reagents with respect to the radionuclide, in this review fluorine-18. For that reason the efficiencies of reactions are generally given in terms of radiochemical yields instead of... 

With the columns improved as recommended above, it is desirable to repeat many off-line experiments performed earlier. To avoid necessity of extra corrections, it is preferable to simultaneously chromatograph as many elements as possible, and to run experiments with this mixture under various experimental conditions. In particular, because our major concern is the column surface, of great interest would be experiments in the columns made of metals or temperature-resistant fluorinated polymers. The polymeric columns remain unemployed in gas-phase radiochemistry. Their surface will probably not be modified, which can lead to unexpected phenomena or regularities. 

A.A. Woolf (1981) Advances in Inorganic Chemistry and Radiochemistry, vol. 24, p. 1 - A review of the thermochemistry of fluorine compounds. 

Kleinberg, J. and Cowan, G. A. 1960. The Radiochemistry of Fluorine, Chlorine, Bromine and Iodine. National Research Council Report NAS-NS 3005. Washington, DC National Research Council. 

Aryliodoniums are alternative precursors to fluorinate inactivated aryl groups with electron-donating or no substituent." " Brady et al. patented the concept of aryliodonium-supported resins for use in fluorine-18 solid-phase radiochemistry, and Scheme 13.4 illustrates this proof-of-concept with the SPOR of uracil 15 with fluorine-18. 

The SPOR of [ FJfluoroDOPA 20, described in Scheme 13.6, used the same radiochemistry as employed in the corresponding solution-phase radiosynthesis. [ F]FluoroDOPA 20 is synthesized by electrophilic fluorine. The fully protected organometallic precursor is attached to the support via a triorganotin moiety in which one of the methyl substituents is replaced by a propyl linker. The cleavage step occurs upon fluorine incorporation, and subsequent acidic treatment furnishes [ FJfluoroDOPA 20. 

Littich R, Scott PJH (2012) Novel strategies for fluorine-18 radiochemistry. Angew Chem Int Ed 51 1106-1109... 

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