- N-difluoromethylation of phenylazoles
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In the presence of one equivalent of NaH, 2- and 4-phenylimidazole and 3-phenyl-1,2,4-triazole can be N-difluoromethylated with ClCF2H. The difluoromethylation of 5-phenyltetrazole requires two equivalents of NaH. A mechanism is proposed to acc
- Lyga, John W.,Patera, Russell M.
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- N -difluoromethylation of imidazoles and benzimidazoles using the ruppert-prakash reagent under neutral conditions
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Direct N-difluoromethylation of imidazoles and benzimidazoles has been achieved using TMS-CF3 (the Ruppert-Prakash reagent) under neutral conditions. Difluoromethylated products were obtained in good-to-excellent yields. Inexpensive, commercial
- Surya Prakash,Krishnamoorthy, Sankarganesh,Ganesh, Somesh K.,Kulkarni, Aditya,Haiges, Ralf,Olah, George A.
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Read Online
- Method for synthesizing N-difluoromethyl-containing compound
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The invention discloses a method for synthesizing a N-difluoromethyl-containing compound. The method comprises reacting a nitrogen-containing nucleophilic reagent as shown in a formula I or III or V as a starting material for 6-24 hours in the presence of
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Paragraph 0046-0049
(2019/12/02)
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- N-Difluoromethylation of imidazoles and pyrazoles using BrCF2PO(OEt)2 under mild condition
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A simple and efficient protocol for the direct N-difluoromethylation of imidazoles and pyrazoles has been developed. The reaction makes use of commercially available, non-ozone-depleting and easy handling BrCF2PO(OEt)2 as difluorocarbene precursor, and provides a cost-efficient and environmentally benign access to some difluoromethylated biologically relevant molecules.
- Mao, Ting,Zhao, Liang,Huang, Yang,Lou, Yue-Guang,Yao, Qiuli,Li, Xiao-Fei,He, Chun-Yang
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supporting information
p. 2752 - 2754
(2018/06/12)
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- Difluoromethylation and gem-difluorocyclopropenation with difluorocarbene generated by decarboxylation
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Difluoromethylation of the activated X-H bond (X = N, O and S) and aliphatic thiols, and gem-difluorocyclopropenation of alkynes with difluorocarbene generated in situ from difluoromethylene phosphobetaine (Ph3P+CF2CO2-) by decarboxylation occurred smoothly without the presence of any base or other additives.
- Deng, Xiao-Yun,Lin, Jin-Hong,Zheng, Jian,Xiao, Ji-Chang
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supporting information
p. 8805 - 8808
(2015/05/20)
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- Use of fluoroform as a source of difluorocarbene in the synthesis of N-CF2H heterocycles and difluoromethoxypyridines
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Fluoroform is used as a source of difluorocarbene to convert various N-, O-, and C-nucleophiles to their difluoromethylated derivatives. Imidazole, benzimidazole, benztriazole, hydroxypyridines, and their derivatives underwent reaction at moderate temperatures and atmospheric pressure, using potassium hydroxide as base in a two-phase (water/acetonitrile) process to provide moderate to good yields of the respective products. Nitrophenols required addition of a co-solvent (methanol) to obtain good yields of products.
- Thomoson, Charles S.,Wang, Linhua,Dolbier, William R.
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- Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine
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Background: 1,1-Difluoroalkenes cannot only be used as valuable precursors for organic synthesis, but also act as bioisosteres for enzyme inhibitors. Among various methods for their preparation, the carbonyl olefination with difluoromethylene phosphonium ylide represents one of the most straightforward methods. Results: The combination of (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl) and triphenylphosphine (PPh3) can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyl)trimethylsilane (TMSCF2Br) and (trifluoromethyl)trimethylsilane (TMSCF3) in this reaction. Conclusion: Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective.
- Wang, Fei,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
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supporting information
p. 344 - 351
(2014/03/21)
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- Synthesis of gem-difluorocyclopropa(e)nes and O-, S-, N-, and P-difluoromethylated compounds with TMSCF2Br
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Two-in-one: Me3SiCF2Br is an efficient difluorocarbene source and is compatible with both neutral and aqueous basic conditions. Bromide-ion-initiated [2+1] cycloaddition with alkenes/alkynes and hydroxide ion promoted α-addition with (thio)phenols, (thio)alcohols, sulfinates, heterocyclic amines, and H-phosphine oxides give the corresponding gem-difluorinated compounds with broad functional-group tolerance. Copyright
- Li, Lingchun,Wang, Fei,Ni, Chuanfa,Hu, Jinbo
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supporting information
p. 12390 - 12394
(2013/12/04)
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- Chlorodifluoromethyl aryl ketones and sulfones as difluorocarbene reagents: The substituent effect
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We have investigated the different chlorodifluoromethyl aryl ketones 1a-1g and sulfones 2a-2h as difluorocarbene reagents for O- and N- difluoromethylations. It was found that the sulfone reagents 2 were generally more efficient in difluoromethylation than the ketone reagents 1. Furthermore, while the different substituents on ketone reagents 1 did not show a remarkable impact on the difluoromethylation reaction, the substituent effect on the sulfone reagents 2 was much more significant. Finally, we found that p-chlorophenyl chlorodifluoromethyl sulfone 2d and p-nitrophenyl chlorodifluoromethyl sulfone 2h were among the most powerful difluorocarbene reagents in this category for O-difluoromethylations.
- Wang, Fei,Zhang, Laijun,Zheng, Ji,Hu, Jinbo
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experimental part
p. 521 - 528
(2011/08/22)
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- N-tosyl-S-difluoromethyl-S-phenylsulfoximine: A new difluoromethylation reagent for S-, N-, and C-nucleophiles
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The first α-difluoromethyl sulfoximine compound, 2, was successfully prepared by using the copper(ll)-catalyzed nitrene transfer reaction. Compound 2 was found to be a novel and efficient difluoromethylation reagent for transferring the CF2H gr
- Zhang, Wei,Wang, Fei,Hu, Jinbo
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supporting information; experimental part
p. 2109 - 2112
(2009/09/30)
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- Chlorodifluoromethyl phenyl sulfone: A novel non-ozone-depleting substance-based difluorocarbene reagent for O- and N-difluoromethylations
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Chlorodifluoromethyl phenyl sulfone, a previously unknown compound that can be readily prepared from non-ODS-based precursors, was found to act as a robust difluorocarbene reagent for O- and N-difluoromethylations. The Royal Society of Chemistry.
- Zheng, Ji,Li, Ya,Zhang, Laijun,Hu, Jinbo,Meuzelaar, Gerrit Joost,Federsel, Hans-Juergen
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p. 5149 - 5151
(2008/09/18)
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- Generation of heteroarylium-N-difluoromethylides and heteroaryl-N-difluoromethyl anions and their reactions with electrophiles: Heteroaryl- and heteroarylium-N-difluoromethyl trimethylsilanes and a new heteroaryl-N-trifluoromethane
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Reductive debromination of N-bromodifluoromethyl-4-dimethylaminopyridinium bromide, 1-bromodifluoromethyl-imidazole, 1-methyl-3-bromodifluoromethyl-imidazolium bromide and 1-bromodifluoromethyl-2-methyl-benzimidazole using tetrakis(dimethylamino)ethylene (TDAE) or tris(diethylamido)phosphite leads to new fluorinated carbanionic species, namely heteroarylium-N-difluoromethylides and heteroaryl-N-difluoromethyl anions. In the presence of electrophiles such as benzaldehyde, chlorodiphenylphosphine and chlorotrimethylsilane, the corresponding heteroarylium- and heteroaryl-N-difluoromethylated derivatives, imidazole-N-difluoromethyl-phosphines and -silanes, 2-methyl-benzimidazole-N-difluoromethyltrimethyl-carbinols-phosphines and -silanes were obtained. Similar 4-dimethylaminopyridinium derivatives were synthesized.
- Bissky, German,Roeschenthaler, Gerd-Volker,Lork, Enno,Barten, Jan,Medebielle, Maurice,Staninets, Vasilij,Kolomeitsev, Alexander A.
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p. 173 - 181
(2007/10/03)
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