Radiochemical 18F-fluoroarylation of unsaturated α-, β- and γ-amino acids, application to a radiolabelled analogue of baclofen

Fluoride Additive as a Simple Tool to Qualitatively Improve Performance of Nickel-Catalyzed Asymmetric Michael Addition of Malonates to Nitroolefins

Nowadays, design of the new chiral ligands for organometallic catalysts is often based on the step-by-step increase in their complexity to improve efficiency. Herein we describe that simple in situ addition of the fluoride source to the asymmetric organometallic catalyst can improve not only activity but also enantioselectivity. Bromide-nickel diimine complexes were found to catalyze asymmetric Michael addition in low yields and ee, but activation with fluoride leads to a significant improvement in catalyst performance. The developed approach was applied to prepare several enantioenriched GABA analogues.

Selective and tunable synthesis of 3-arylsuccinimides and 3-arylmaleimides from arenediazonium tetrafluoroborates and maleimides

A highly efficient and tunable synthetic strategy for 3-arylsuccinimides or 3-arylmaleimides has been developed from arenediazonium tetrafluoroborates and maleimides with satisfactory yields in the presence of TiCl₃ or CuCl.

Fast and efficient (18) F-labeling by [(18) f]fluorophenylazocarboxylic esters

Introduction of [(18) F]fluoride ion into the aromatic core of phenylazocarboxylic esters was achieved in only 30 seconds, with radiochemical yields of up to 95 % (85(±10) %). For labeling purposes, the resulting (18) F-substituted azoester can be further converted in radical-arylation reactions to give biaryls, or in substitutions at its carbonyl unit to produce azocarboxamides.

Pentakis(trifluoromethyl)benzenediazonium Cation: A Useful Building Block for the Syntheis of Trifluoromethyl-Substituted Derivatives

The sterically crowded, highly electron-deficient diazonium salt C₆ (CF₃ )₅ N₂ ⁺ BF₄ ^- has been synthesized and sample dediazotization reactions were carried out. New compounds, C₆ (CF₃ )₅ I, C₆ (CF₃ )₅ NO₂ , and C₆ (CF₃ )₅ NO were isolated and identified. Also, a more convenient route to C₆ (CF₃ )₅ NH₂ that gave good yield was achieved.

Synthesis, biological evaluation and radiolabelling by 18F-fluoroarylation of a dopamine D3-selective ligand as prospective imaging probe for PET

Radical (18)F-fluoroarylation with fluorine-18-labelled arenediazonium chlorides has been successfully applied to the radiochemical synthesis of the dopamine D(3)-selective ligand SH 317 ([(18)F]8). SH 317 has been evaluated as a new PET ligand candidate by in vivo experiments.