217326-89-1Relevant articles and documents
2-[ 18 F]Fluorophenylalanine: Synthesis by Nucleophilic 18 F-Fluorination and Preliminary Biological Evaluation
Modemann, Daniel J.,Zlatopolskiy, Boris D.,Urusova, Elizaveta A.,Zischler, Johannes,Craig, Austin,Ermert, Johannes,Guliyev, Mehrab,Endepols, Heike,Neumaier, Bernd
, p. 664 - 676 (2019/01/23)
2-[ 18 F]Fluorophenylalanine (2-[ 18 F]FPhe), a promising PET tracer for imaging of cerebral infarction and tumors, was efficiently prepared from an easily accessible iodonium salt precursor using Cu-mediated radiofluorination under 'low base' or 'minimalist' conditions. Whereas significant racemization was initially observed if the 'minimalist' protocol was applied for radiolabeling, it was completely suppressed by the careful adjustment of 18 F - preprocessing. The initial biological study revealed a higher uptake of 2-[ 18 F]FPhe in different tumor cells in comparison to that of [ 18 F]FET. In contrast to 4-[ 18 F]FPhe, which suffered from rapid defluorination in vivo, 2-[ 18 F]FPhe demonstrated a sufficient in vivo stability. Conclusively, 2-[ 18 F]FPhe is a promising PET probe that is now readily available using Cu-mediated radiofluorination under 'minimalist' or 'low base' conditions. The simplicity of the translation of the proposed procedures to automated synthesis modules allows a broad biological evaluation of 2-[ 18 F]FPhe. Notably, a novel protocol for the preparation of N -Boc protected amino acids from the respective Ni-Schiff base complexes was developed that avoided application of strongly acidic conditions.
Homocoupling of iodoarenes and bromoalkanes using photoredox gold catalysis: A light enabled Au(III) reductive elimination
Tran, Huy,McCallum, Terry,Morin, Mathieu,Barriault, Louis
supporting information, p. 4308 - 4311 (2016/09/09)
The formation of homocoupled alkane byproducts have been identified in the reduction of bromoalkanes via photoredox gold catalysis with dimeric Au(I) complexes. This prompted further investigation into the mechanism of formation of these byproducts and the diversity of C-X bonds amenable to this transformation. Examples were found when considering bromoalkanes while a wide variety of iodoarenes underwent this process in good to excellent yields. The light enabled homocoupling of iodoarenes made possible by photoredox gold catalysis is reported.
C-Glycosyl amino acids through hydroboration-cross-coupling of exo-glycals and their application in automated solid-phase synthesis
Koch, Stefan,Schollmeyer, Dieter,L?we, Holger,Kunz, Horst
supporting information, p. 7020 - 7041 (2013/07/05)
O-Glycosylation is one of the most important post-translational modifications of proteins. The attachment of carbohydrates to the peptide backbone influences the conformation as well as the solubility of the conjugates and can even be essential for binding to specific ligands in cell-cell interactions or for active transport over membranes. This makes glycopeptides an interesting class of compounds for medical applications. To enhance the long-term availability of these molecules in vivo, the stabilization of the glycosidic bond between the amino acid residue and the carbohydrate is of interest. The described modular approach affords β-linked C-glycosyl amino acids by a sequence of Petasis olefination of glyconolactones, stereoselective hydroboration and a mild B-alkyl-Suzuki coupling reaction. The coupling products were transformed to C-glycosyl amino acid building-blocks suitable for solid-phase synthesis and successfully incorporated into a partial sequence of the tumor-associated MUC1-glycopeptide. The resulting C-glycopeptides are candidates for the development of long-term stable mimics of O-glycopeptide vaccines. Copyright
