- Zinc(II) Complexes of N,N-Di(2-picolyl)hydrazones
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We report on N,N-di(2-picolyl)hydrazone (DPH) ligands that are capable of binding metal ions in two isomeric forms depending on the nature of the hydrazone substituent. When the hydrazone substituent is not coordinating, the metal ion prefers the N,N-di(2-picolyl)amino (DPA) site, which is a known tridentate ligand that anchors on the sp3-hybridized amino nitrogen atom. When the hydrazone substituent is coordinating, the metal ion instead anchors on the sp2-hybridized imino nitrogen atom to afford a different structural isomer. Zinc(II) is used as a representative transition-metal ion for characterizing the coordination chemistry of DPH in both solution and solid states.
- Barsoum, David N.,Kyeremeh-Mensah, Lawrence,Meisner, Quinton J.,Clark, Ronald J.,Masson, Eric,Zhu, Lei
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- DNA interaction, anticancer, antibacterial, ROS and lipid peroxidation studies of quinoxaline based organometallic Re(I) carbonyls
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Hetero mononuclear rhenium(I) complexes (I-V) using ligands (L1-L5) [L1-L5 = 11-((2-chlorobenzylidene)hydrazono)-11H-indeno[1,2-b]quinoxaline (L1), 8-methyl-11-((4-methyl-benzylidene)hydrazono)-11H-indeno[1,2-b]quinoxaline (L2), 11-((4-bromobenzylidene) hydrazono)-8-nitro-11H-indeno[1,2-b]quinoxaline (L3), 11-((4-bromobenzylidene) hydrazono)-8-chloro-11H-indeno[1,2-b]quinoxaline (L4), 8-bromo-11-((4-fluorobenzylidene) hydrazono)-11H-indeno[1,2-b]quinoxaline (L5)] were synthesized and characterized by spectroscopic method. All the synthesized compounds have biological importance. DNA interaction studies gave information about the modes of binding and the nucleolytic efficiency of compounds. The binding of the rhenium complexes to Herring sperm DNA (HS DNA) was monitored by UV–visible spectroscopy, viscosity measurements, and molecular docking studies; groove binding was suggested as the most possible mode. The DNA-complexes binding strength was measured in terms of intrinsic binding constants. In vivo and In vitro cytotoxicity against the eukaryotic and prokaryotic cells gave the toxic nature of the synthesized compounds. An antimicrobial study was carried out by estimating MIC (Minimum Inhibitory Concentration) against two Gram-positive (S. aureus, B. subtilis) and three Gram-negative (S. marcescens, P. aeruginosa, E. coli) bacteria. All synthesized complexes are biologically more active than the corresponding ligands. Complexes were having higher MDA and H2O2 production than ligands.
- Varma, Reena R.,Pandya, Juhee G.,Vaidya, Foram U.,Pathak, Chandramani,Dabhi, Ravi A.,Dhaduk, Milan P.,Bhatt, Bhupesh S.,Patel, Mohan N.
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- Submonomer synthesis of peptoids containingtrans-inducingN-imino- andN-alkylamino-glycines
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The use of hydrazones as a new type of submonomer in peptoid synthesis is described, giving access to peptoid monomers that are structure-inducing. A wide range of hydrazones were found to readily react with α-bromoamides in routine solid phase peptoid submonomer synthesis. Conditions to promote a one-pot cleavage of the peptoid from the resin and reduction to the correspondingN-alkylamino side chains were also identified, and both theN-imino- andN-alkylamino glycine residues were found to favor thetrans-amide bond geometry by NMR, X-ray crystallography, and computational analyses.
- Davern, Carolynn M.,Ison, Elon A.,Lowe, Brandon D.,Proulx, Caroline,Rosfi, Adam
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p. 8401 - 8410
(2021/06/28)
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- Copper-Catalyzed Conjugate Addition of Carbonyls as Carbanion Equivalent via Hydrazones
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Copper-catalyzed conjugate addition is a classic method for forming new carbon-carbon bonds. However, copper has never showed catalytic activity for umpolung carbanions in hydrazone chemistry. Herein, we report a facile conjugate addition of hydrazone catalyzed by readily available copper complexes at room temperature. The employment of mesitylcopper(I) and electron-rich phosphine bidentate ligand is a key factor affecting reactivity. The reaction allows various aromatic hydrazones to react with diverse conjugated compounds to produce 1,4-adducts in yields of about 20 to 99%.
- Luo, Siyi,Peng, Marie,Querard, Pierre,Li, Chen-Chen,Li, Chao-Jun
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p. 13111 - 13117
(2021/09/18)
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- Synergistic Relay Reactions To Achieve Redox-Neutral α-Alkylations of Olefinic Alcohols with Ruthenium(II) Catalysis
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Herein, we report a ruthenium-catalyzed redox-neutral α-alkylation of unsaturated alcohols based on a synergistic relay process involving olefin isomerization (chain walking) and umpolung hydrazone addition, which takes advantage of the interaction between the two rather inefficient individual reaction steps to enable an efficient overall process. This transformation shows the compatibility of hydrazone-type “carbanions” and active protons in a one-pot reaction, and at the same time achieves the first Grignard-type nucleophilic addition using olefinic alcohols as latent carbonyl groups, providing a higher yield of the corresponding secondary alcohol than the classical hydrazone addition to aldehydes does. A broad scope of unsaturated alcohols and hydrazones, including some complex structures, can be successfully employed in this reaction, which shows the versatility of this approach and its suitability as an alternative, efficient means for the generation of secondary and tertiary alcohols.
- Kan, Jian,Li, Chao-Jun,Li, Chen-Chen,Li, Jianbin,Lv, Leiyang,Qiu, Zihang
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supporting information
p. 4544 - 4549
(2020/02/04)
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- Switch in Selectivity for Formal Hydroalkylation of 1,3-Dienes and Enynes with Simple Hydrazones
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Controlling reaction selectivity is a permanent pursuit for chemists. Regioselective catalysis, which exploits and/or overcomes innate steric and electronic bias to deliver diverse regio-enriched products from the same starting materials, represents a powerful tool for divergent synthesis. Recently, the 1,2-Markovnikov hydroalkylation of 1,3-dienes with simple hydrazones was reported to generate branched allylic compounds when a nickel catalyst was used. As part of the effort, shown here is that a complete switch of Markovnikov to anti-Markovnikov addition is obtained by changing to a ruthenium catalyst, thus providing direct and efficient access to homoallylic products exclusively. Isotopic substitution experiments indicate that no reversible hydro-metallation across the metal-π-allyl system occurred under ruthenium catalysis. Moreover, this protocol is applicable to the regiospecific hydroalkylation of the distal C=C bond of 1,3-enynes.
- Li, Chao-Jun,Lv, Leiyang,Qiu, Zihang,Yu, Lin
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supporting information
p. 6466 - 6472
(2020/03/13)
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- Reduction over Condensation of Carbonyl Compounds through a Transient Hemiaminal Intermediate Using Hydrazine
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Reduction of carbonyl moieties to the corresponding alcohol using simply hydrazine hydrate has been considerably unfeasible until now due to the well-known condensation reaction. However, herein, we report that using an excess of 20-fold equivalents, the reduction proceeds in excellent yields. 1H NMR study of the reaction and density functional theory (DFT) calculations indicate that the final fate of the hemiaminal intermediate is crucial to obtain the alcohol or the hydrazone.
- Vilches-Herrera, Marcelo,Gallardo-Fuentes, Sebastián,Aravena-Opitz, Mauricio,Yá?ez-Sánchez, Mauricio,Jiao, Haijun,Holz, Jens,B?rner, Armin,Lühr, Susan
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p. 9213 - 9218
(2020/08/14)
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- Nickel-catalyzed cross-coupling of umpolung carbonyls and alkyl halides
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An effective nickel-catalyzed cross-coupling of Umpolung carbonyls and alkyl halides was developed. Complementary to classical alkylation techniques, this reaction utilizes Umpolung carbonyls as the environmentally benign alkyl nucleophiles, providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
- Zhu, Dianhu,Lv, Leiyang,Qiu, Zihang,Li, Chao-Jun
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- Nickel-Catalyzed Cross-Coupling of Umpolung Carbonyls and Alkyl Halides
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An effective nickel-catalyzed cross-coupling of Umpolung carbonyls and alkyl halides was developed. Complementary to classical alkylation techniques, this reaction utilizes Umpolung carbonyls as the environmentally benign alkyl nucleophiles, providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
- Zhu, Dianhu,Lv, Leiyang,Qiu, Zihang,Li, Chao-Jun
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p. 6312 - 6322
(2019/05/24)
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- Denitrogenative Hydrotrifluoromethylation of Benzaldehyde Hydrazones: Synthesis of (2,2,2-Trifluoroethyl)arenes
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Reacting hydrazones of arylaldehydes with Togni's CF3-benziodoxolone reagent, in the presence of potassium hydroxide and cesium fluoride, induces a denitrogenative hydrotrifluoromethylation event to produce (2,2,2-trifluoroethyl)arenes. This novel reaction was tolerant to many electronically-diverse functional groups and substitution patterns, as well as naphthyl- and heteroaryl-derived substrates. Advantages of this process include the easy access to hydrazone precursors on a large scale, speed and operational simplicity, and being transition metal-free.
- Zhao, Zhensheng,Ma, Kevin C. Y.,Legault, Claude Y.,Murphy, Graham K.
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supporting information
p. 11240 - 11245
(2019/08/20)
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- Synthesis, antiproliferative and pro-apoptotic effects of nitrostyrenes and related compounds in Burkitt’s lymphoma
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Background: Cancers of the lymphatic cells (lymphomas) account for approximately 12% of malignant diseases worldwide. The nitrostyrene scaffold is identified as a lead target structure for the development of particularly effective compounds targeting Burkitt’s lymphoma (BL). Objectives: The aims of the curent study were to synthesise a panel of nitrostyrene compounds and to evaluate their activity in Burkitt’s lymphoma (BL). Methods: A panel of structurally varied compounds were designed and synthesised using Henry Knoevenagel condensation reactions. Single crystal X-Ray analysis confirmed the E configuration for six examples of these novel structures. A number of nitrostyrene-related compounds were also investigated including 1,3-bis(aryl)-2-nitropropenes together with heterocyclic scaffolds containing the nitrovinyl pharmacophore such as 3-nitro-2-phenyl-2H-chromenes. The antiproliferative activities of the compounds were evaluated using the BL cell lines EBV- MUTU-1 and EBV+ DG-75 (chemoresistant) to establish preliminary structure-activity relationships. Results: Lead compounds with optimized nitrostyrene scaffolds and 3-nitro-2-phenyl-2Hchromene structures were successfully established with typical IC50 values of 0.45 μM and 0.47 μM in MUTU-1 cells and 1.41 μM and 1.92 μM, respectively, in DG-75 cells. The mechanism of cell death was identified as apoptotic and the lead compound was found to elicit comparable apoptotic effects to Taxol in Burkitt’s lymphoma cell lines MUTU-1 and DG-75. Conclusion: This class of pharmaceutically active compounds with potential for the treatment of Burkitt’s lymphoma suggest a potential role for nitrostyrene based agents in chemotherapy.
- Byrne, Andrew J.,Bright, Sandra A.,Fayne, Darren,McKeown, James P.,McCabe, Thomas,Twamley, Brendan,Williams, Clive,Meegan, Mary J.
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p. 181 - 199
(2018/03/13)
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- Green, Catalyst-Free Reaction of Indoles with β-Fluoro-β-nitrostyrenes in Water
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The reaction of 2-fluoro-2-nitrostyrenes with various indoles was investigated. We found that the reaction proceeds as a Michael addition in a highly regioselective manner to form 3-(1-aryl-2-fluoro-2-nitroethyl)-1H-indoles. Thus, a green and catalyst-free synthesis of these compounds was developed using water as a reaction medium. The high effectiveness of this approach was demonstrated through the preparation of target products in up to 92 % isolated yield. Subsequent reduction of the nitro group was investigated. We found that due to the instability of the intermediate α-fluoro amines, the reduction led to non-fluorinated tryptamine derivatives.
- Aldoshin, Alexander S.,Tabolin, Andrey A.,Ioffe, Sema L.,Nenajdenko, Valentine G.
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p. 3816 - 3825
(2018/07/31)
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- Umpolung of Carbonyl Groups as Alkyl Organometallic Reagent Surrogates for Palladium-Catalyzed Allylic Alkylation
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Palladium-catalyzed allylic alkylation of nonstabilized carbon nucleophiles is difficult and remains a major challenge. Reported here is a highly chemo- and regioselective direct palladium-catalyzed C-allylation of hydrazones, generated from carbonyls, as a source of umpolung unstabilized alkyl carbanions and surrogates of alkyl organometallic reagents. Contrary to classical allylation techniques, this umpolung reaction utilizes hydrazones prepared not only from aryl aldehydes but also from alkyl aldehydes and ketones as renewable feedstocks. This strategy complements the palladium-catalyzed coupling of unstabilized nucleophiles with allylic electrophiles by providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
- Zhu, Dianhu,Lv, Leiyang,Li, Chen-Chen,Ung, Sosthene,Gao, Jian,Li, Chao-Jun
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supporting information
p. 16520 - 16524
(2018/11/23)
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- Rapid Asymmetric Synthesis of Disubstituted Allenes by Coupling of Flow-Generated Diazo Compounds and Propargylated Amines
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We report herein the asymmetric coupling of flow-generated unstabilized diazo compounds and propargylated amine derivatives, using a new pyridinebis(imidazoline) ligand, a copper catalyst and base. The reaction proceeds rapidly, generating chiral allenes in 10–20 minutes with high enantioselectivity (89–98 % de/ee), moderate yields and a wide functional group tolerance.
- Poh, Jian-Siang,Makai, Szabolcs,von Keutz, Timo,Tran, Duc N.,Battilocchio, Claudio,Pasau, Patrick,Ley, Steven V.
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supporting information
p. 1864 - 1868
(2017/02/05)
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- Synthesis of Aryldihalomethanes by Denitrogenative Dihalogenation of Benzaldehyde Hydrazones
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We report a denitrogenative dihalogenation reaction of phenyldiazomethanes in which the hypervalent iodine reagents PhICl2 and TolIF2 act as surrogates for elemental chlorine and fluorine. Halogen transfer from iodane to aryldiazomethane is described, as is a tandem oxidative dihalogenation reaction between iodane and hydrazone. This is the first use of non-α-stabilized diazo compounds in this reaction, which provided an efficient synthesis of aryldifluoromethane (ArCHF2) and aryldichloromethane (ArCHCl2) derivatives. (Figure presented.).
- Zhao, Zhensheng,Kulkarni, Kaivalya G.,Murphy, Graham K.
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supporting information
p. 2222 - 2228
(2017/07/07)
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- A Versatile Room-Temperature Route to Di- and Trisubstituted Allenes Using Flow-Generated Diazo Compounds
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A copper-catalyzed coupling reaction between flow-generated unstabilized diazo compounds and terminal alkynes provides di- and trisubstituted allenes. This extremely mild and rapid transformation is highly tolerant of several functional groups. Well tolerated: A mild copper-catalyzed coupling reaction between unstabilized diazo compounds (generated in flow) and terminal alkynes is reported. The method provides di- and trisubstituted allenes with high functional-group tolerance.
- Poh, Jian-Siang,Tran, Duc N.,Battilocchio, Claudio,Hawkins, Joel M.,Ley, Steven V.
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supporting information
p. 7920 - 7923
(2015/06/30)
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- Cyclopropanation using flow-generated diazo compounds
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We have devised a room temperature process for the cyclopropanation of electron-poor olefins using unstabilised diazo compounds, generated under continuous flow conditions. This protocol was applied to a wide range of different diazo species to generate f
- Roda, Nuria M.,Tran, Duc N.,Battilocchio, Claudio,Labes, Ricardo,Ingham, Richard J.,Hawkins, Joel M.,Ley, Steven V.
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supporting information
p. 2550 - 2554
(2015/11/17)
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- Design and synthesis of a new family of fluorinated liquid crystals
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A convenient and simple three-step pathway to the new family of CF 2CF2S-bridged alkanes and CF2S-, CF 2O-bridged alkenes and alkynes was elaborated by using catalytic olefination reaction as a key step of the s
- Nenajdenko, Valentine G.,Goldberg, Aleksey A.,Muzalevskiy, Vasily M.,Balenkova, Elizabeth S.,Shastin, Aleksey V.
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p. 2370 - 2383
(2013/03/28)
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- Cobalt(II) phthalocyanine-catalyzed highly chemoselective reductive amination of carbonyl compounds in a green solvent
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Cobalt phthalocyanine has been employed for the highly chemoselective reductive amination of aldehydes and ketones in ethanol as a green solvent. A large range of functional groups such as nitro, acid, amide, ester, nitrile, halogen, lactone, methoxy, hydroxy, alkene, N-benzyl, O-benzyl and heterocyclic rings were well tolerated under the present reaction conditions. Copyright
- Kumar, Vishal,Sharma, Upendra,Verma, Praveen K.,Kumar, Neeraj,Singh, Bikram
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supporting information; experimental part
p. 870 - 878
(2012/05/04)
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- Highly regioselective synthesis of 1,3,5-trisubstituted 1,2,4-triazole derivatives
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The synthesis of 1,3,5-trisubstituted-1,2,4-triazoles is described. The key reaction is the thermal cyclization of an amidrazone intermediate with the aminal of an aromatic aldehyde. The method allows a variety of functionalities to be incorporated to add diversity to the initial templates.
- Ellis, David,Arias-Wood, Aurelio
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experimental part
p. 1703 - 1712
(2011/06/20)
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- Novel efficient synthesis of β-fluoro-β-(trifluoromethyl)styrenes
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CF3CFBr2 was employed in catalytic olefination reactions of aromatic aldehydes. In situ prepared hydrazones of aldehydes were transformed to β-fluoro-β-(trifluoromethyl)styrenes by reaction with CF3CFBr2 under CuCl catalysis. Based on this reaction, a novel stereoselective approach towards β-fluoro-β-(trifluoromethyl)styrenes was elaborated. Nucleophilic vinylic substitution of fluorine by secondary amines, thiolates and alkoxides in β-fluoro-β-(trifluoromethyl)styrenes was also tested.
- Goldberg, Aleksey A.,Muzalevskiy, Vasiliy M.,Shastin, Aleksey V.,Balenkova, Elisabeth S.,Nenajdenko, Valentine G.
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experimental part
p. 384 - 388
(2010/04/24)
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- A new method for the synthesis of cinnamonitriles by catalytic olefination
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Catalytic olefination of hydrazones of aromatic aldehydes with dibromoacetonitrile affords cinnamonitriles.
- Nenajdenko,Golubinskii,Lenkova,Shastin,Balenkova
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p. 252 - 254
(2007/10/03)
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- Reaction of CBrF2-CBrF2 with hydrazones of aromatic aldehydes. Novel efficient synthesis of fluorocontaining alkanes, alkenes and alkynes
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An olefination of hydrazones of aromatic aldehydes by CBrF2-CBrF2 under copper catalysis was investigated. In situ prepared aldehydes hydrazones were converted to (3-bromo-2,2,3,3-tetrafluoropropyl)arenes by reaction with CBrF2-CBrF2 in the presence of CuCl. Subsequent elimination of HF by sodium hydroxide resulted in stereospecific formation of fluorocontaining alkenes. Elimination proceeds stereoselectively, only Z -isomers of alkenes are formed. Elimination of two molecules of HF from (3-bromo-2,2,3,3-tetrafluoropropyl)arenes by treatment with potassium tert -butoxide leads to formation of (bromodifluoromethyl)alkynes. As a result a simple and efficient transformation of aromatic aldehydes to range of various fluorinated alkanes, alkenes and alkynes was elaborated.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Korotchenko, Vasily N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 1339 - 1345
(2007/10/03)
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- A novel direct synthesis of (2,2-difluorovinyl)benzenes from aromatic aldehydes
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A novel catalytic approach to (2,2-difluorovinyl)benzenes has been developed. It was found that hydrazones of aromatic aldehydes generated in situ could be converted to the corresponding (2,2-difluorovinyl)benzenes by catalytic olefination reaction (COR) with dibromodifluoromethane in the presence of CuCl.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Korotchenko, Vasily N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 115 - 118
(2007/10/03)
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- A novel approach to fluoro-containing alkenes
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A new and general one-pot transformation of aromatic aldehydes to fluorinated olefins containing -CH=C(Cl)CF3 or -CH=C(F)CClF2 moieties is described. Freons CCl3CF3 and CCl2FCClF2 were used as trifluoromethyl and difluoromethyl C2-building blocks respectively. A proposed mechanism for the reaction is discussed.
- Korotchenko, Vasily N,Shastin, Alexey V,Nenajdenko, Valentine G,Balenkova, Elisabeth S
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p. 7519 - 7527
(2007/10/03)
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- A novel synthetic approach to dichlorostyrenes
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We found that N-unsubstituted hydrazones of aromatic aldehydes can be easily converted to the corresponding 1,1-dichlorostyrenes in the reaction with carbon tetrachloride using copper (I) chloride as catalyst. Factors affecting the route of the reaction and yields of the products were investigated. A proposed mechanism for the reaction is discussed. (C) 2000 Published by Elsevier Science Ltd.
- Shastin,Korotchenko,Nenajdenko,Balenkova
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p. 6557 - 6563
(2007/10/03)
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