• Journal of the Korean Chemical Society
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• v.54 no.6
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• pp.744-748
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• 2010

2,3,4,5-Tetrafluorobenzoic acid, an important intermediates of fluoroquinolone antibiotics, was synthesized from tetrachloride phthalic anhydride through imidation, fluorination, hydrolysis and decarboxylation. The effects of phase transfer catalyst on imidation and fluorination reaction and the effects of surfactants on the hydrolysis reaction were studied, respectively. Experimental results showed that the imidation reaction time was greatly reduced in the presence of a phase transfer catalyst, hexadecyltrimethyl, resulting in imidation yield as high as 98.2%. The fluorination yield reached 81.3% when tetrabutylammonium bromide was chosen as a phase transfer catalyst. The hydrolysis reaction time was also decreased by adding hexadecyltrimethyl while increasing the yield to 88.6%. In the post-processing, the sublimation method was used to purify the product, and ideal effect was obtained. In the decarboxylation reaction, tetrafluoride phthalic acid was obtained by decarboxylation in the solvent of tri-n-butyl amine and decarboxylation yield reached 81.6%. Compared with the literature method, the overall reaction time of the improved method decreased from 53 h to 20.5 h and the total yield increased from 47.3% to 57.4%.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2635-2644
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• 2014

Gold-catalyzed tandem cyclization-oxidative alkynylation and cyclization-fluorination reactions of 2-alkynone O-methyloximes are described. The reactions proceed smoothly at room temperature in the presence of 10 mol % of $(PPh_3)AuNTf_2$, 2.5 equivalents of selectfluor, and 2 equivalents of $K_3PO_4$. 2-Alkynone O-methyloximes undergo intramolecular oxyauration/cyclization and ensuing oxidative cross-coupling and fluorination process to afford the corresponding 3,4,5-trisubstituted isoxazoles in a cascade manner.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.122-128
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• 2017

In the 2000s, there has been a significant advance on carbon-fluorine (C-F) bond formation reactions via transition metal mediated or catalyzed methods. Of course, for the past 10 years, transition metal catalysis improves C-F bond formation in terms of practicality and even can be applied to C-18F bond formation reaction. In this mini-review, we summarize various transition metal mediated or catalyzed fluorination reactions, which were developed in the mid-2000s.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.116-121
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• 2017

To overcome the low reactivity and solubility of alkali metal fluorides (MFs), various types of phase transfer catalysts (PTCs) have been developed over the last decades. However, since the fluoride activated by such PTC sometimes has a strong basicity, it may cause various side reactions such as elimination reaction or hydroxylation reaction in the nucleophilic fluorination reaction. Also, they may cause separation problems in the compound purification process. In recent advanced study, various PTCs have been developed to solve these problem of conventional catalyst. In this review, we would like to introduce three kinds of novel multifunctional organic catalysts such as bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA), easy separable pyrene-tagged ionic liquid (PIL) by reduced graphene oxide (rGO), and tri-tert-butanolamine organic catalyst.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.7 no.2
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• pp.141-146
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• 2021

With increasing interest in fluorinated compounds, nucleophilic fluorination reaction has been generally used for synthesizing fluorine-containing chemicals. However, alkali metal fluorides (MFs) generally have low solubility and reactivity in organic solvent. To overcome these problems, various phase transfer catalysts (PTCs) have been investigated. Calix-arene is known as to capture the metal cation(M⁺), and therefore in this review, we would like to introduce several kinds of calix-arene based PTCs, such as bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA), oligo-ethylene glycol linked bis-triethyleneglycol crown-5-calix[4]arene (BTC5A), and ionic liquid functionalized calix-arene based catalyst, as well as ion-pair receptor crown-6-calix[4]arene-capped calix[4]pyrrole.

• Applied Chemistry for Engineering
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• v.27 no.5
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• pp.537-542
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• 2016

In this study, we have prepared mesophase pitch from pyrolysis fuel oil (PFO) by heterogeneous reforming process. This process was conducted by direct fluorination at various temperature and followed by the heat treatment at $390^{\circ}C$. The reformed pitch was then investigated by softening point analysis, elemental analysis, fourier-transform infrared spectroscopy, high resolution X-ray diffraction and polarization microscope analysis. Carbon contents of reformed pitch increased according to increasing the reaction temperature of fluorination, while oxygen, nitrogen and sulfur contents were completely eliminated. As the fluorination temperature increased, the creation, growth, coalescence and alignment process of mesophase spheres were observed. Also the interlayer spacing of carbon hexagonal planar structure decreased, while its crystalline size increased. In addition, aromatic ring compound contents increased by the condensation polymerization of aliphatic compound. These results can be attributed to the radical reactivity of the fluorine increased as the reaction temperature increased. It was considered that the fluorination reaction could help PFO to generate aromatic compounds, via promoting polymerization by radical reaction.

• Bulletin of the Korean Chemical Society
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• v.27 no.3
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• pp.423-425
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• 2006

• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2191-2192
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• 2007

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.413-416
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• 2001

여러 가지 기능성 섬유나 섬유복합재료에서는 가공성이나 계면접착성 향상 및 응용성을 높이기 위하여 섬유 표면을 개질하여 사용하는 경우가 많다. 지금까지 연구된 섬유의 표면개질 방법으로는 화학적 처리방법, 광화학적 방법, 플라즈마 처리법 등이 개발되어 있다. 화학적 방법은 장비가 간단한 장점이 있지만 사용 약품이 대부분 강한 독성을 지니고 있어서 작업 및 환경오염에 큰 문제점이 있고, 광화학적 방법은 radiation 에너지가 커야 하고 광에너지의 차폐 문제가 있다. (중략)

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.4 no.2
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• pp.121-123
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• 2018

Fluoride is one of most important atoms for both clinical and pharmaceutical usage. Associated with such a strong need, $^{18}F$-fluoride has been widely used as an essential radioisotope. The fluoride always suffers from strong solvation effects through strong hydrogen bonding, which reduce the reactivity of fluoride anion. To enhance the reactivity, the concept of naked fluoride was introduced in the fluorination field. In this essay, I will briefly describe the history of naked fluoride concept and development of naked fluoride sources.