Recent developments in photoredox-catalyzed remote ortho and para C–H bond functionalizations

• Rafia Siddiqui and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26

• bonds in the presence of photoredox catalyst 8, with a similar mechanism as shown in Figure 22, and the photocatalytic mechanism was elucidated by nanosecond laser flash photolysis (Scheme 24) [168]. Fluorine-18 is an important radioisotope used in the radiopharmaceutical industry (e.g., for drug

• (5a). Monofluorination using QuCN-ClO4 (8). Fluorination with fluorine-18. Aerobic amination with acridinium catalyst 3a. Aerobic aminations with semiconductor photoredox catalyst 18. Perfluoroalkylation of arenes. Synthesis of benzonitriles in the presence of 3a. Acknowledgments We are grateful to

Synthesis of a dihalogenated pyridinyl silicon rhodamine for mitochondrial imaging by a halogen dance rearrangement

• Jessica Matthias,
• Thines Kanagasundaram,
• Klaus Kopka and
• Carsten S. Kramer

Beilstein J. Org. Chem. 2019, 15, 2333–2343, doi:10.3762/bjoc.15.226

• rearrangement. By our optimized procedure, we have obtained the dye 15 at high yield and without the necessity of HPLC purification. The chlorine atom in 2’-position can potentially be used to introduce the PET radionuclide fluorine-18 while the bromine atom serves as a constraint against rotation around the

Microfluidic radiosynthesis of [¹⁸F]FEMPT, a high affinity PET radiotracer for imaging serotonin receptors

• Thomas Lee Collier,
• Steven H. Liang,
• J. John Mann,
• Neil Vasdev and
• J. S. Dileep Kumar

Beilstein J. Org. Chem. 2017, 13, 2922–2927, doi:10.3762/bjoc.13.285

• Psychiatric Institute, New York, NY, USA 10.3762/bjoc.13.285 Abstract Continuous-flow microfluidics has shown increased applications in radiochemistry over the last decade, particularly for both pre-clinical and clinical production of fluorine-18 labeled radiotracers. The main advantages of microfluidics are

• agreement with the known distribution of the 5-HT1AR. Despite the excellent binding profile of [11C]MPT, the slow washout in baboons limits this radiotracer from advancing to human studies. Our recent efforts have focused on the development of fluorine-18 (t½ = 109.7 min) labelled MPT derivatives, as the

• receptor, [18F]FEMPT (pKi = 9. 79; Ki = 0.16 nM) by microfluidic radiochemistry. [18F]FEMPT was obtained in ≈7% isolated radiochemical yield and in >98% radiochemical and chemical purity. The molar activity of the final product was determined to be >148 GBq/µmol (>4 Ci/µmol). Keywords: agonist; fluorine

Synthesis, dynamic NMR characterization and XRD studies of novel N,N’-substituted piperazines for bioorthogonal labeling

• Constantin Mamat,
• Marc Pretze,
• Matthew Gott and
• Martin Köckerling

Beilstein J. Org. Chem. 2016, 12, 2478–2489, doi:10.3762/bjoc.12.242

• respective reference compounds for later radiolabeling purposes. Finally, a procedure to synthesize the building blocks containing fluorine-18 was evaluated. Results and Discussion Synthesis of the piperazine compounds Low-cost starting materials were applied for the preparation of all novel building blocks

Use of 3-[¹⁸F]fluoropropanesulfonyl chloride as a prosthetic agent for the radiolabelling of amines: Investigation of precursor molecules, labelling conditions and enzymatic stability of the corresponding sulfonamides

• Reik Löser,
• Steffen Fischer,
• Achim Hiller,
• Martin Köckerling,
• Uta Funke,
• Aurélie Maisonial,
• Peter Brust and
• Jörg Steinbach

Beilstein J. Org. Chem. 2013, 9, 1002–1011, doi:10.3762/bjoc.9.115

• Chemistry Group, Albert-Einstein-Straße 3a, 18059 Rostock, Germany 10.3762/bjoc.9.115 Abstract 3-[18F]Fluoropropanesulfonyl chloride, a recently proposed prosthetic agent for fluorine-18 labelling, was prepared in a two-step radiosynthesis via 3-[18F]fluoropropyl thiocyanate as an intermediate. Two

• of the analogous fluoroacetamide. Keywords: fluorine-18; hydrolytic metabolism; prosthetic groups; radiochemistry; sulfonamides; Introduction The importance of molecular imaging, i.e., the characterisation and measurement of biological processes in living organisms at the molecular level using

• , fluorine-18 can be considered as the most suitable one for PET due to its intermediate half-life of 109.8 min, its high content of β+-conversion (97%) and its rather low positron energy maximum of 640 keV [2]. From a chemical point of view, the introduction of fluorine-18 into molecules that are able to

Single and double stereoselective fluorination of (E)-allylsilanes

• Marcin Sawicki,
• Angela Kwok,
• Matthew Tredwell and
• Véronique Gouverneur

Beilstein J. Org. Chem. 2007, 3, No. 34, doi:10.1186/1860-5397-3-34

• chirality when reacting allylsilanes B with electrophiles other than fluorine. [18][19][20][21] Chiral allylsilanes B are known to act as useful carbon nucleophile equivalents in highly stereoselective condensation reactions with a large range of electrophiles leading to the construction of C-C, C-O, C-N or