Novel strategies for fluorine-18 radiochemistry.

摘要: Positron (b) emission tomography (PET) is a powerful, noninvasive tool for the in vivo, three-dimensional imaging of physiological structures and processes. PET involves incorporation short-lived radionuclides, particularly carbon-11 fluorine-18, into biologically active molecules. The resulting radiopharmaceuticals are introduced human subjects, liberating positrons decay process that subsequently annihilate with electrons adjacent matter. Detection g radiation generated during annihilation allows well-defined images ongoing bodily processes to be obtained. Understandably, wielding this technology— which requires manipulation strong radioemitters, short end-product efficacy timeframes, rigorous quality control—is not simple undertaking. In answer this, speaking its clinical value, research pertaining has observed exciting rapid growth. prospective applications innumerable. Exploiting fullest potential been limited, however, large part, by availability pertinent radiopharmaceuticals. identification suitable radionuclide use labeling concern intrinsic preparation radiopharmaceutical agents. Carbon-11 fluorine-18 commonly used each own merits. Radiolabeling C advantages include minimal effects on substrate biological activity ease incorporation. C-radiolabeling also affords ability run multiple scans per day series. However, suffers from rather half-life (20 min) susceptibility environmental contamination processing. F finds utility light fact bioactive species sometimes affects their pharmacological profile. Fluorine-18 offers benefit substantial (about 110 min, allowing distribution satellite scan facilities), clean (97% b emission) limited positron migration 1 mm, leading highly resolved images). Indeed, ubiquitous molecular tomography, as exemplified success [F]2-fluoro2-deoxy-d-glucose (FDG) oncology research. [F]Fluoride prepared proton bombardment oxygen-18 enriched water through nuclear reaction O(p,n)F. Aqueous solutions rendered, ion interest can isolated ion-exchange chromatography. Gaseous [F]F2 available Ne(d,a)F. former facilitates nucleophilic fluorination reactions; latter, electrophilic fluorination. Both modes have important This article discusses recent strides field radiochemistry, categorized motif. Gouverneur co-workers recently disclosed [F]Selectfluor bis(triflate) means broaden scope radiochemistry. Inspired mild, commercially fluorinating agent Selectfluor, was chloromethylation diazabicyclo[2.2.2]octane, anion exchange, subsequent using high-specific (Scheme 1).