693785-25-0Relevant academic research and scientific papers
Tailor-made hexaethylene glycolic ionic liquids as organic catalysts for specific chemical reactions
Jadhav, Vinod H.,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee,Kim, Dong Wook
, p. 2502 - 2505 (2011)
Chemical equations presented. Hexaethylene glycol substituted imidazolium based ionic liquids (hexaEGILs) were designed and prepared well-tailored to a specific organic reaction using alkali-metal fluorides (MFs) as multifunctional organic catalysts. These hexaEGIL catalysts could significantly enhance the reactivity of MF, even KF. Furthermore, the hexaEGIL systems showed tremendous efficiency in the nucleophilic fluorination of base-sensitive substrates.
Pyrene-Tagged Alcoholic Ionic Liquids as Phase Transfer Catalysts for Nucleophilic Fluorination
Taher, Abu,Kim, Dong Wook
supporting information, p. 1140 - 1146 (2020/10/15)
Functional group?activity relationships of pyrene-tagged ionic liquid (PTIL)-based organocatalysts for nucleophilic fluorination using alkali metal fluorides (MFs) are described, which demonstrate that the pyrene, oligoether and alcohol moieties on the imidazolium ring are vital for efficient catalysis. Further investigation of these findings led to the discovery of new strategy, which showed superior catalyst separation process, i.e., catalyst is effortlessly separated from the reaction mixture using reduced graphene oxide. The catalytic efficiency of the PTIL as a phase transfer catalyst was demonstrated by the high conversion of the reactants up to 98% fluorinated yield using MFs in CH3CN or t-amyl alcohol. Importantly, the catalyst not only enhanced the reactivity of bimolecular nucleophilic substitutions (SN2) within a short reaction time and reduces the formation of by-products but also affords high yield with easy isolation and separation under mild conditions.
Rapid Deoxyfluorination of Alcohols with N-Tosyl-4-chlorobenzenesulfonimidoyl Fluoride (SulfoxFluor) at Room Temperature
Guo, Junkai,Kuang, Cuiwen,Rong, Jian,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
supporting information, p. 7259 - 7264 (2019/05/10)
The deoxyfluorination of alcohols is a fundamentally important approach to access alkyl fluorides, and thus the development of shelf-stable, easy-to-handle, fluorine-economical, and highly selective deoxyfluorination reagents is highly desired. This work describes the development of a crystalline compound, N-tosyl-4-chlorobenzenesulfonimidoyl fluoride (SulfoxFluor), as a novel deoxyfluorination reagent that possesses all of the aforementioned merits, which is rare in the arena of deoxyfluorination. Endowed by the multi-dimensional modulating ability of the sulfonimidoyl group, SulfoxFluor is superior to 2-pyridinesulfonyl fluoride (PyFluor) in fluorination rate, and is also superior to perfluorobutanesulfonyl fluoride (PBSF) in fluorine-economy. Its reaction with alcohols not only tolerates a wide range of functionalities including the more sterically hindered alcoholic hydroxyl groups, but also exhibits high fluorination/elimination selectivity. Because SulfoxFluor can be easily prepared from inexpensive materials and can be safely handled without special techniques, it promises to serve as a practical deoxyfluorination reagent for the synthesis of various alkyl fluorides.
Bis-tert-Alcohol-Functionalized Crown-6-Calix[4]arene: An Organic Promoter for Nucleophilic Fluorination
Jadhav, Vinod H.,Choi, Wonsil,Lee, Sung-Sik,Lee, Sungyul,Kim, Dong Wook
supporting information, p. 4515 - 4520 (2016/03/22)
A bis-tert-alcohol-functionalized crown-6-calix[4]arene (BACCA) was designed and prepared as a multifunctional organic promoter for nucleophilic fluorinations with CsF. By formation of a CsF/BACCA complex, BACCA could release a significantly active and selective fluoride source for SN2 fluorination reactions. The origin of the promoting effects of BACCA was studied by quantum chemical methods. The role of BACCA was revealed to be separation of the metal fluoride to a large distance (>8 ?), thereby producing an essentially "free" F-. The synergistic actions of the crown-6-calix[4]arene subunit (whose O atoms coordinate the counter-cation Cs+) and the terminal tert-alcohol OH groups (forming controlled hydrogen bonds with F-) of BACCA led to tremendous efficiency in SN2 fluorination of base-sensitive substrates.
Oligoethylene glycols as highly efficient mutifunctional promoters for nucleophilic-substitution reactions
Jadhav, Vinod H.,Jang, Seung Ho,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee,Kim, Ju-Young,Lee, Sungyul,Lee, Ji Woong,Song, Choong Eui,Kim, Dong Wook
supporting information; experimental part, p. 3918 - 3924 (2012/06/01)
Herein, we report the promising use of n-oligoethylene glycols (oligoEGs) as mutifunctional promoters for nucleophilic-substitution reactions employing alkali metal salts. Among the various oligoEGs tested, pentaethylene glycol (pentaEG) had the most efficient catalytic activity. In particular, when compared with other nucleophiles examined, a fluorine nucleophile generated from CsF was significantly activated by the pentaEG promoter. We also performed various facile nucleophilic-displacement reactions, such as the halogenation, acetoxylation, thioacetoxylation, nitrilation, and azidation of various substrates with potassium halides, acetate, thioacetate, cyanide, and sodium azide, respectively, in the presence of the pentaEG promoter. All of these reactions provided their desired products in excellent yields. Furthermore, the combination of pentaEG and a tert-alcohol medium showed tremendous efficiency in the nucleophilic-displacement reactions (fluorination and methoxylation) of base-sensitive substrates with basic nucleophiles (cesium fluoride and potassium methoxide, respectively). The catalytic role of oligoEGs was examined by quantum-chemical methods. The oxygen atoms in oligoEGs were found to act as Lewis bases on the metal cations to produce the "flexible" nucleophile, whereas the two terminal hydroxy (OH) groups acted as "anchors" to orientate the nucleophile and the substrate into an ideal configuration for the reaction. The EG race: OligoEGs, such as pentaethylene glycol (pentaEG), act as mutifunctional promoters for nucleophilic-substitution reactions with the corresponding alkali-metal salts. The combination of pentaEG and a tert-alcohol media system showed tremendous efficiency in the fluorination and methoxylation of base-sensitive substrates by using the corresponding basic nucleophiles (see figure). Copyright
Polymer-supported pentaethylene glycol as a facile heterogeneous catalyst for nucleophilic fluorination
Jadhav, Vinod H.,Jang, Seung Ho,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee,Chi, Dae Yoon,Kim, Dong Wook
supporting information; experimental part, p. 3740 - 3743 (2010/11/05)
Polymer-supported pentaethylene glycols (PSpentaEG) as promising catalysts for nucleophilic fluorination with alkali metal fluoride (MF) could significantly enhance the nucleophilicity of MF and provide simple purification and recycling in the reaction. F
Tetrabutylammonium tetra(tert-butyl alcohol)-coordinated fluoride as a facile fluoride source
Kim, Dong Wook,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee
supporting information; body text, p. 8404 - 8406 (2009/05/15)
(Figure Presented) F- on: The title compound TBAF(tBuOH) 4 can act as a highly effective fluoride source for nucleophilic fluorination thanks to its favorable properties, such as a stable structure (in which the fluoride ion is surrounded by four bulky nonpolar protic alcohol molecules), a dehydrated state, low hygroscopicity, good solubility in organic solvents, good nucleophilicity, and low basicity.
Facile nucleophilic fluorination reactions using tert-alcohols as a reaction medium: Significantly enhanced reactivity of alkali metal fluorides and improved selectivity
Dong, Wook Kim,Jeong, Hwan-Jeong,Seok, Tae Lim,Sohn, Myung-Hee,Katzenellenbogen, John A.,Dae, Yoon Chi
, p. 957 - 962 (2008/09/18)
(Chemical Equation Presented) Although protic solvents are generally not preferred for nucleophilic displacement reactions because of their partial positive charge and hydrogen-bonding capacity that solvate the nucleophile and reduce its reactivity, we recently reported a remarkably beneficial effect of using tertiary alcohols as a reaction media for nucleophilic fluorination with alkali metal fluorides, as well as fluorine-18 radiolabeling with [ 18F]fluoride ion for the preparation of PET radiopharmaceuticals. In this work, we investigate further the influence of the tert-alcohol reaction medium for nucleophilic fluorination with alkali metal fluorides by studying various interactions among tert-alcohols, the alkali metal fluoride (CsF), and the sulfonyloxy substrate. Factors such as hydrogen bonding between CsF and the tert-alcohol solvent, the formation of a tert-alcohol solvated fluoride, and hydrogen bonding between the sulfonate leaving group and the tert-alcohol appear to contribute to the dramatic increase in the rate of the nucleophilic fluorination reaction in the absence of any kind of catalyst. We found that fluorination of 1-(2-mesyloxyethyl)naphthalene (5) and N-5-bromopentanoyl-3,4- dimethoxyaniline (8) with Bu4N+F- in a tert-alcohol afforded the corresponding fluoro products in much higher yield than obtained by the conventional methods using dipolar aprotic solvents. The protic medium also suppresses formation of byproducts, such as alkenes, ethers, and cyclic adducts.
Facile nucleophilic fluorination by synergistic effect between polymer-supported ionic liquid catalyst and tert-alcohol reaction media system
Kim, Dong Wook,Jeong, Hwan-Jeong,Lim, Seok Tae,Sohn, Myung-Hee,Chi, Dae Yoon
, p. 4209 - 4214 (2008/09/19)
A highly efficient method was developed for nucleophilic fluorination using an alkali metal fluoride through the synergistic effect of the polymer-supported ionic liquid (PSIL) as a catalyst and tert-alcohol as an alternative reaction media. This PSIL/tert-alcohol system not only enhances the reactivity of alkali metal fluorides and reduces the formation of by-products but also allows the use of a polymer-supported catalyst protocol. As an example, the nucleophilic fluorinations of the model compound, 2-(3-bromopropoxy)naphthalene, with CsF using only tert-amyl alcohol as solvent (for 2 h reaction time), 0.5 equiv of PS[hmim][BF4] in CH3CN (for 12 h reaction time), and 0.5 equiv of PS[hmim][BF4] in tert-amyl alcohol (which is a PSIL/tert-alcohol system for the synergistic effect; for 2 h reaction time) provided 18, 40, and 84% yield, respectively. The characteristics of the nucleophilic fluorination reactions of some halo- and alkanesulfonyloxyalkane systems to the corresponding fluoroalkanes using various alkali metal fluorides are also reported.
