Radiofluorination of arylboronic acids pinacol esters (arylBPin) mediated by copper triflate pyridine complex is one of the more promising synthetic approaches for the direct introduction of nucleophilic [18F]fluoride into non‐activated arenes and heteroarenes. However, the application of this method to the production of positron emission tomography (PET) radiotracers in automated synthesizers remains a challenging task. The choice of phase‐transfer catalyst (PTC) and corresponding base used for the generation of reactive [18F]fluoride species has a profound impact on the efficiency of the 18F‐fluorination process. Herein we report the development of a simple procedure involving trapping of the aqueous [18F]fluoride on a weak anion‐exchange resin (WAX) and its release by elution with pyridinium sulfonate in dimethyl acetamide. Obtained reactive [18F]fluoride was used as‐is in a copper‐catalyzed fluorination reaction employing pyridinium salt as both PTC and base. High radiochemical conversion rates (RCCs) achieved for a series of simple arylBPin substrates and 4‐[18F]fluoro‐D,L‐phenylalanine demonstrate the efficiency of this novel 18F‐processing approach. Notably, the proposed method obviates conventional azeotropic drying steps, solvents evaporation and/or changeover and can be implemented on commercial automated synthesizers.

The rise of the transition‐metal‐mediated and/or catalyzed radiofluorination reactions has led us to investigate possibilities for the improvement of the radiolabeling yields of pinacol esters of arylboronic acids (arylBPin) in the presence of Cu(OTf)2(py)4. Addition of small amounts pyridine to the reaction medium with DMF as a solvent and [18F]F−/K222Cs+complex as [18F]fluoride source was shown to have a significant positive effect on the radiofluorination yields. The effect was investigated in depth using 4‐biphenylboronic acid pinacol ester as a model compound, with up to 20 % increase in radiochemical conversion observed at optimized conditions. Maximum effect was observed at pyridine‐to‐catalyst ratio of 30:1. The findings were applied to a representative electron‐rich ring systems that are traditionally difficult or impossible to radiolabel with nucleophilic fluoride, leading to products such as 2‐[18F]fluoroanisole and protected 4‐L‐[18F]fluorophenylalanine. Given the ever‐present pressure to develop new methods for introduction of fluorine‐18 into various substrates to facilitate easy and robust production of clinically‐relevant radiotracers for PET imaging we believe our findings can be of significant practical interest for radiofluorination of ortho‐substituted substrates in particular.

Nowadays chemistry of 68Ga‐labelled radiopharmaceuticals is one of the drivers for Positron Emission Tomography (PET). Buffers solutions for radiolabelling play one of the important roles here. Despite HEPES buffer providing high radiochemical conversions, its use is undesirable due to high toxicity. In this article we report a simple procedure involving usage of aqueous triethanolammonium (TEA) and tris(hydroxymethyl)methyl‐ammonium (TRIS) salts of biologically active carboxylic acids in a process of gallium‐68 complexation with PSMA‐HBED‐CC. These salts provide not only high radiochemical conversions but also are already widely used in biochemistry, molecular biology, agriculture and medicine as drugs of a wide spectrum of action and growth stimulating drugs (Trekrezan™, Chlorokrezacin™).

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