Development of 18F-fluorinatable dendrons and their application to cancer cell targeting

Stoichiometric Leverage: Rapid 18F‐Aryltrifluoroborate Radiosynthesis at High Specific Activity for Click Conjugation

“…12 Ci mmol À1 . Previously, we [9c, 11,14] and others [15] noted the potential for imaging with [ 18 F]-ArBF 3 À , but with added carrier that gave clononane-1,4,7-triacetic acid) chelates and [ 18 F]-SiFA analogues that were labeled at SAs of 7 Cimmol À1 prior to conjugation, [16] we chose to show similar compatibility, but with higher SA.…”

Boron–18F containing positron emission tomography radiotracers: advances and opportunities

“…Smith and co-workers developed a high-yielding method for conjugation of both boronic esters and aryltrifluoroborates to amine-terminating molecules (see Scheme 9) (49,50). The initial reaction was carried out using the commercially available 2,6-difluoro-4-formylphenylboronic acid pinacol ester with (o-carboxymethyl)hydroxylamine and Hünig's base.…”

“…The labelled compound was shown (after purification) to bind to HER-2 expressing cells in vitro that were 'pre-targeted' with the avidin-trastuzumab conjugate. An attempt was made to improve the signal level detected in PET imaging studies by incorporating multiple 18 F labelled moieties using poliamidoamine dendrimers to provide several amine terminating points available for the attachment of multiple arylboronic esters and a thiol group suitable for a biotin-amide (50). After functionalization of the dendrimers with biotin and various arylboronic precursors, the radiofluorination and purification were carried out using similar methods to the previous study.…”

“…The reaction was also attempted using the tetraphenyl benzopinacolate derivative, which gave the desired product in a 79% yield, with no deboronated by-product present (44). Smith and co-workers developed a high-yielding method for conjugation of both boronic esters and aryltrifluoroborates to amine-terminating molecules (see Scheme 9) (49,50). The initial reaction was carried out using the commercially available 2,6-difluoro-4-formylphenylboronic acid pinacol ester with (o-carboxymethyl)hydroxylamine and Hünig's base.…”

Abstracts of the 20th International Isotope Society (UK group) Symposium: Synthesis & Applications of Labelled Compounds 2011

“…We have developed three biotin precursors for [ 18 F] labelling: oxy‐amine‐biotin conjugate. which was labelled using [ 18 F]FDG as a prosthetic group; a conjugate of biotin and boroaryl, which was [ 18 F]labelled in aqueous solution; a conjugate of biotin with 4, 8 and 16 branched dendrons functionalised with trifluoroboroaryl, which were labelled using isotopic exchange.…”