Multifunctional Crown-5-calix[4]arene-based Phase-Transfer Catalysts for Aromatic 18F-Fluorination
Won Chang Lee1,2, Seok Min Kang3, Byung Chul Lee1,4
1Department of Nuclear Medicine, Seoul National University Hospital, Seongnam 13620, Republic of Korea.
Abstract:
Methylated bis-triethylene glycolic crown-5-calix[4]arene (M-BTC5A) as a phase-transfer catalyst showed the best performance among other analogues and even conventional Kryptofix 222 in the nucleophilic aromatic 18F-fluorination of diaryliodonium tosylate precursors owing to (i) the efficient release of reactive "naked" [18F]fluoride, (ii) the high stabilization of the precursor in the reaction, and, presumably, (iii) the ease of access between the precursor and the K18F/M-BTC5A complex facilitated by π-π interactions. [18F]Flumazenil was produced in high radiochemical yield using M-BTC5A.
More Related Videos
19:58Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Related Concept Videos
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Crown Ethers
Electrophilic Aromatic Substitution: Friedel–Crafts Acylation of Benzene
Electrophilic Aromatic Substitution: Friedel–Crafts Alkylation of Benzene
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
