172304-05-1Relevant articles and documents
A new approach for the synthesis of [11C]-labeled fatty acids
Wuest,Dence,McCarthy,Welch
, p. 1289 - 1300 (2000)
The synthesis of ω-[11C], ω-1-[11C] and ω-3-[11C] palmitic acid employing a cross-coupling reaction between a functionalized copper-zinc reagent with [11C]MeI, [1-11C]EtI and [1-11C]BuI is described. A tert.-butyl-protected ω-iodo fatty acid precursor (t)BuO2C-(CH2)(n)-I (n = 11, 13, 14) was converted into the corresponding dialkylzinc reagent [(t)BuO2C-(CH2)(n)]2Zn which reacts with Me2CuI(MgCl)2 to give a highly reactive copper reagent [(t)BuO2C-(CH2)(n)]2CuI(MgCl)2Me2Zn as the labeling precursor. The cross-coupling reaction with [11C]MeI, [1-11C]EtI and [1-11C]BuI provided the protected palmitic acid, specifically labeled with carbon-11 in several positions. The corresponding carbon-13 labeled compounds were synthesized to verify the labeling position. In a typical synthesis with [1-11C]EtI starting with 250 mCi of [11C]CO2, 14 mCi (6% decay-corrected based on [11C]CO2) of ω-1-[11C]palmitic acid was obtained within 30 minutes after EOB in 88% radiochemical purity prior to purification by HPLC. The general feature of this approach allows the convenient synthesis of palmitic acid specifically labeled in the ω, ω-1 or ω-3 positions by using several [11C]-labeled alkyl iodides ([11C]MeI, [1-11C]EtI or [1-11C]BuI) in the same cross-coupling protocol.
Facilitating functionalization of benzene-1,3,5-tricarboxamides by switching amide connectivity
Dhiman, Shikha,Palmans, Anja R. A.,Schoenmakers, Sandra M. C.,Su, Lu,van den Bersselaar, Bart W. L.
supporting information, p. 8281 - 8294 (2021/10/12)
Synthetic water-compatible supramolecular polymers based on benzene-1,3,5-tricarboxamides (BTAs) have attracted a lot of interest in recent years, as they are uniquely suited to generate functional multicomponent biomaterials. Their morphologies and intrinsic dynamic behaviour mimic fibrous structures found in nature. Moreover, their modularity allows control of the density of functionalities presented on the surface of the fibres when using functionalized BTA monomers. However, such moieties generally comprise a functionality on only one of three side chains, resulting in lengthy synthetic protocols and limited yields. In this work, we avert the need for desymmetrization of the core by starting from commercially available 5-aminoisophthalic acid. This approach eliminates the statistical reactions and reduces the number of synthetic steps. It also leads to the inversion of the connectivity of one of the amides to the benzene core. By combining spectroscopy, light scattering and cryogenic transmission electron microscopy, we confirm that the inversed amide BTAs (iBTAs) form intermolecular hydrogen bonds and assemble into supramolecular polymers, like previously used symmetrical BTAs, albeit with a slight decrease in water solubility. Solubility problems were overcome by incorporating iBTAs into conventional BTA-based supramolecular polymers. These two-component mixtures formed supramolecular fibres with a morphology and dynamic behaviour similar to BTA-homopolymers. Finally, iBTAs were decorated with a fluorescent dye to demonstrate the synthesis of functional monomers, and to visualize their co-assembly with BTAs. Our results show that functionality can be introduced into supramolecular polymers with monomers that slightly differ in their core structure while maintaining the structure and dynamics of the fibres.
