- Hydrazone Based Dual – Responsive Colorimetric and Ratiometric Chemosensor for the Detection of Cu2+/F? Ions: DNA Tracking, Practical Performance in Environmental Samples and Tooth Paste
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Colorimetric sensors have attracted wide scope of attentions due to its fascinating advantages, like handy, equipment-free and naked eye detections. In this investigation, a new and novel hydrazone based dual-responsive ratiometric/colorimetric chemosenso
- Anbu Durai, Willsingh,Ramu, Andy
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- Ruthenium catalyzed β-selective alkylation of vinylpyridines with aldehydes/ketonesviaN2H4mediated deoxygenative couplings
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Umpolung (polarity reversal) tactics of aldehydes/ketones have greatly broadened carbonyl chemistry by enabling transformations with electrophilic reagents and deoxygenative functionalizations. Herein, we report the first ruthenium-catalyzed β-selective alkylation of vinylpyridines with both naturally abundant aromatic and aliphatic aldehyde/ketonesviaN2H4mediated deoxygenative couplings. Compared with one-electron umpolung of carbonyls to alcohols, this two-electron umpolung strategy realized reductive deoxygenation targets, which were not only applicable to the regioselective alkylation of a broad range of 2/4-alkene substituted pyridines, but also amenable to challenging 3-vinyl and steric-embedded internal pyridines as well as their analogous heterocyclic structures.
- Lv, Leiyang,Li, Chao-Jun
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p. 2870 - 2875
(2021/03/14)
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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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- Synthesis and biological evaluation of novel (E)-N'-benzylidene hydrazides as novel c-Met inhibitors through fragment based virtual screening
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C-Met plays a crucial role in the development and progression of neoplastic disease. Type II c-Met inhibitors recognise the inactive DFG-out conformation of the kinase, result in better anti-tumour effects due to synergistic effect against the other kinas
- Li, Shi-long,Li, Wan-qiu,Liang, Jing-wei,Meng, Fan-hao,Wang, Shan
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p. 468 - 477
(2020/01/08)
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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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- Structural studies of 2,5-disubstituted 1,3,4-thiadiazole derivatives from dithioesters under the mild condition: Studies on antioxidant, antimicrobial activities, and molecular docking
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A series of 2,5-disubstituted 1,3,4-thiadiazole was synthesized and evaluated for their antioxidant and molecular docking studies. These molecules were efficiently synthesized under mild and inexpensive starting material. Construction of these molecules developed using substituted aldehydes and substituted dithioesters in presence of NCS (N-Chorosuccinimide). The compounds 4a, 4b, 4c, 4f, and 4k showed good antibacterial and antioxidant activity among which, 4k possess excellent antibacterial and antioxidant activity. The results of antioxidant activity studies revealed that compound 4k manifested profound antioxidant potential. The molecular docking study was performed with respective newly synthesized compounds to ascertain the binding mode of 4k with respect to the critical proteins involved in biosynthesis and metabolic pathways.
- Gowda, Kemparaje,Kanchugarkoppal, Rangappa S.,Kempegowda, Mantelingu,Nagarakere, Sandhya C.,Rangappa, Shobith,Swarup, Hassan A.
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- Efficient Multigram Approach to Acetylenes and CF3-ynones Starting from Dichloroalkenes Prepared by Catalytic Olefination Reaction (COR)
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A novel approach to terminal acetylenes based on catalytic olefination reaction COR of arylaldehydes to form dichloroalkenes followed by treatment with nBuLi was elaborated. This method is atom economical and displays high yields and effectivity. The corresponding alkynes can be prepared in up to 97 % yield. One pot procedure towards CF3-ynones was elaborated to provide these products in up to 87 % yield starting from dichloroalkenes.
- Muzalevskiy, Vasiliy M.,Sizova, Zoia A.,Diusenov, Arstan I.,Shastin, Alexey V.,Nenajdenko, Valentine G.
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supporting information
p. 4161 - 4166
(2020/07/13)
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- Acid-Mediated Three Component Assembly of 4-Fluoropyrazoles from α-Fluoronitroalkenes, Hydrazines, and Aldehydes
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A new approach for the synthesis of highly pharmaceutically relevant 4-fluoropyrazoles via oxidative annulation of α-fluoronitroalkenes with in situ prepared hydrazones was developed. The reaction is efficiently promoted by trifluoroacetic acid while atmo
- Ioffe, Sema L.,Motornov, Vladimir A.,Nelyubina, Yulia V.,Nenajdenko, Valentine G.,Tabolin, Andrey A.
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- Nickel-catalyzed alkyl-alkyl cross-coupling reactions of non-activated secondary alkyl bromides with aldehydes as alkyl carbanion equivalents
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A novel nickel-catalyzed alkyl-alkyl cross coupling of non-activated secondary alkyl bromides with aldehydes via hydrazone intermediates has been developed. Aldehydes as alkyl carbanion equivalents replace traditional organometallic reagents. This coupling occurs on the carbon of the hydrazone rather than the nitrogen. In addition, non-activated primary and tertiary alkyl bromides also undergo the cross-coupling reaction to form new C(sp3)-C(sp3) bonds in moderate yields.
- Zhu, Chenghao,Zhang, Junliang
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supporting information
p. 2793 - 2796
(2019/03/06)
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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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- Umpolung cross-coupling of polyfluoroarenes with hydrazones: Via activation of C-F bonds
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An umpolung strategy for the cross-coupling of polyfluoroarenes with various substituted hydrazones to construct C(sp2)-C(sp3) bonds is developed. In this strategy, the C-F bond of polyfluoroarenes is cleaved and coupled with moisture- and air-stable hydrazones under mild conditions with good to excellent yields. This method provides a useful tool for synthesizing polyfluorinated pharmaceuticals and functional materials.
- Cao, Dawei,Pan, Pan,Zeng, Huiying,Li, Chao-Jun
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supporting information
p. 9323 - 9326
(2019/08/08)
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- Nickel-Catalyzed Regioselective Hydrobenzylation of 1,3-Dienes with Hydrazones
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Hydroalkylation of unsaturated hydrocarbons with unstabilized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far have mainly focused on the involvement of heteroatom and/or stabilized carbon nucleophiles as efficient reaction partners. Reported here is an unprecedented regioselective nickel-catalyzed hydrobenzylation of 1,3-dienes with hydrazones, generated in situ from abundant aryl aldehydes and ketones and acting as both the sources of unstabilized carbanion equivalent and hydride. With this strategy, both terminal and sterically hindered internal dienes are hydroalkylated efficiently in a highly selective manner, thus providing a reliable catalytic method to construct challenging C(sp3)-C(sp3) bonds.
- Lv, Leiyang,Zhu, Dianhu,Qiu, Zihang,Li, Jianbin,Li, Chao-Jun
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p. 9199 - 9205
(2019/10/14)
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- Nickel-catalyzed cross-coupling of aldehydes with aryl halides: Via hydrazone intermediates
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Traditional cross-couplings require stoichiometric organometallic reagents. A novel nickel-catalyzed cross-coupling reaction between aldehydes and aryl halides via hydrazone intermediates has been developed, merging the Wolff-Kishner reduction and the classical cross-coupling reactions. Aromatic aldehydes, aryl iodides and aryl bromides are especially effective in this new cross-coupling chemistry.
- Tang, Jianting,Lv, Leiyang,Dai, Xi-Jie,Li, Chen-Chen,Li, Lu,Li, Chao-Jun
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supporting information
p. 1750 - 1753
(2018/02/21)
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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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- Cross-Coupling of Phenol Derivatives with Umpolung Aldehydes Catalyzed by Nickel
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A nickel-catalyzed cross-coupling to construct the C(sp2)-C(sp3) bond was developed from two sustainable biomass-based feedstocks: phenol derivatives with umpolung aldehydes. This strategy features the in situ generation of moisture/air-stable hydrazones from naturally abundant aldehydes, which act as alkyl nucleophiles under catalysis to couple with readily available phenol derivatives. The avoidance of using both halides as the electrophiles and organometallic or organoboron reagents (also derived from halides) as the nucleophiles makes this method more sustainable. Water tolerance, great functional group (ketone, ester, free amine, amide, etc.) compatibility, and late-stage elaboration of complex biological molecules exemplified its practicability and unique chemoselectivity over organometallic reagents.
- Lv, Leiyang,Zhu, Dianhu,Tang, Jianting,Qiu, Zihang,Li, Chen-Chen,Gao, Jian,Li, Chao-Jun
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p. 4622 - 4627
(2018/05/22)
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- Iron-Catalyzed Nucleophilic Addition Reaction of Organic Carbanion Equivalents via Hydrazones
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Earth-abundant and well-defined iron complexes are found to be cheap and effective catalysts for a series of "umpolung" nucleophilic additions of hydrazones. The new catalytic system not only maintains the broad substrate scope of an earlier expensive ruthenium system but also attains chemoselectivity of different kinds of carbonyl groups. Furthermore, the iron catalyst enables this reaction at ambient temperature.
- Li, Chen-Chen,Dai, Xi-Jie,Wang, Haining,Zhu, Dianhu,Gao, Jian,Li, Chao-Jun
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supporting information
p. 3801 - 3805
(2018/07/25)
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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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- Solvent-free ring cleavage hydrazinolysis of certain biginelli pyrimidines
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Certain Biginelli pyrimidines with ester substitution in C5 were subjected to unexpected ring opening upon solvent-free reaction with hydrazine hydrate to give three products: pyrazole, arylidenehydrazines, and urea/thiourea, respectively. The nonisolable carbohydrazide intermediates are formed firstly followed by the intermolecular nucleophilic attack of terminal amino group of hydrazide function on sp2 C6 rather than the sp3 C4 to give the ring adduct which was produced as a final product.
- Said, Mohamed A.,Eldehna, Wagdy M.,Ghabbour, Hazem A.,Kabil, Maha M.,Al-shakliah, Nasser S,Abdel-Aziz, Hatem A
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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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- Investigation of the dinuclear effect of aluminum complexes in the ring-opening polymerization of ε-caprolactone
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A series of aluminum (Al) complexes bearing hydrazine-bridging Schiff base and salen ligands were synthesized and investigated as catalysts for the ring-opening polymerization of ε-caprolactone (CL). The introduction of steric bulky groups increases the catalytic activity of the corresponding mononuclear aluminum complex. However, the opposite phenomenon was observed in dinuclear Al complexes bearing salen ligands because the steric repulsion reduced the cooperative activation mechanism in the dinuclear Al system. Among these Al complexes, LN2Bu-Al2Me4 bearing a hydrazine-bridging Schiff base ligand had the highest catalytic activity, approximately 3- to 11-fold higher than that of dinuclear Al complexes bearing salen ligands and mononuclear Al complexes bearing Schiff base ligands. Density functional theory calculations revealed that the mechanism of the coordination of CL to one Al center was initiated by the benzyl alkoxide of another Al center.
- Hsu, Chiao-Yin,Tseng, Hsi-Ching,Vandavasi, Jaya Kishore,Lu, Wei-Yi,Wang, Li-Fang,Chiang, Michael Y.,Lai, Yi-Chun,Chen, Hsing-Yin,Chen, Hsuan-Ying
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p. 18851 - 18860
(2017/04/10)
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- Aldehydes as alkyl carbanion equivalents for additions to carbonyl compounds
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Nucleophilic addition reactions of organometallic reagents to carbonyl compounds for carbon-carbon bond construction have played a pivotal role in modern chemistry. However, this reaction's reliance on petroleum-derived chemical feedstocks and a stoichiometric quantity of metal have prompted the development of many carbanion equivalents and catalytic metal alternatives. Here, we show that naturally occurring carbonyls can be used as latent alkyl carbanion equivalents for additions to carbonyl compounds, via reductive polarity reversal. Such 'umpolung' reactivity is facilitated by a ruthenium catalyst and diphosphine ligand under mild conditions, delivering synthetically valuable secondary and tertiary alcohols in up to 98% yield. The unique chemoselectivity exhibited by carbonyl-derived carbanion equivalents is demonstrated by their tolerance to protic reaction media and good functional group compatibility. Enantioenriched tertiary alcohols can also be accessed with the aid of chiral ligands, albeit with moderate stereocontrol. Such carbonyl-derived carbanion equivalents are anticipated to find broad utility in chemical bond formation.
- Wang, Haining,Dai, Xi-Jie,Li, Chao-Jun
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p. 374 - 378
(2017/04/03)
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- Carbonyls as Latent Alkyl Carbanions for Conjugate Additions
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Conjugate addition of carbon nucleophiles to electron-deficient olefins is one of the most powerful methods for forming carbon–carbon bonds. Despite great achievements in controlling the selectivity, variation of the carbon nucleophiles remains largely underexplored, with this approach relying mostly on organometallic reagents. Herein, we report that naturally abundant carbonyls can act as latent carbon nucleophiles for conjugate additions through a ruthenium-catalyzed process, with water and nitrogen as innocuous byproducts. The key to our success is homogeneous ruthenium(II) catalysis, combined with phosphines as spectator ligands and hydrazine as the reducing agent. This chemistry allows the incorporation of highly functionalized alkyl fragments into a vast array of electron-deficient olefins under mild reaction conditions in a reaction complementary to the classical organometallic-reagent-based conjugate additions mediated or catalyzed by “soft” transition metals.
- Dai, Xi-Jie,Wang, Haining,Li, Chao-Jun
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supporting information
p. 6302 - 6306
(2017/05/19)
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- Umpolung Addition of Aldehydes to Aryl Imines
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One of the classical ways to synthesize amines involves the coupling of carbonyl compounds and imines, either through enolate chemistry or acyl-based carbanion equivalents. We herein report an alternative strategy that is based on the use of aldehydes as alkyl carbanion equivalents in a reductive coupling with aryl imines. A wide array of secondary amines can be synthesized in moderate to high yields. This reaction is mediated by hydrazine and catalyzed by ruthenium(II) complexes, and it tolerates various functional groups, such as esters, amides, and nitriles.
- Chen, Ning,Dai, Xi-Jie,Wang, Haining,Li, Chao-Jun
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supporting information
p. 6260 - 6263
(2017/05/19)
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- The diaza-Nazarov cyclization involving a 2,3-diaza-pentadienyl cation for the synthesis of polysubstituted pyrazoles
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An unprecedented iodine-mediated diaza-Nazarov (DAN) type cyclization for the construction of substituted pyrazoles from easily available starting materials via an enamine-iminium ion intermediate is described. The oxidative cyclization worked under green conditions with remarkable regioselectivity. This one-pot, efficient and operationally simple three-component intramolecular regioselective DAN cyclization displayed a wide range of substrate scope. The dichotomy of reaction pathways has been explored with density functional theory in the gas phase and solution phase. Of the possible 1,5-, 1,6-, and 1,7-electrocyclizations, the DAN cyclization, i.e., the 1,5-pathway offers the lowest activation energy barrier supporting our experimental observations.
- Aegurla, Balakrishna,Peddinti, Rama Krishna
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p. 9643 - 9652
(2017/11/30)
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- Improvement in Titanium Complexes Bearing Schiff Base Ligands in the Ring-Opening Polymerization of L-Lactide: A Dinuclear System with Hydrazine-Bridging Schiff Base Ligands
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A series of titanium (Ti) complexes bearing hydrazine-bridging Schiff base ligands were synthesized and investigated as catalysts for the ring-opening polymerization (ROP) of L-lactide (LA). Complexes with electron withdrawing or steric bulky groups reduced the catalytic activity. In addition, the steric bulky substituent on the imine groups reduced the space around the Ti atom and then reduced LA coordination with Ti atom, thereby reducing catalytic activity. All the dinuclear Ti complexes exhibited higher catalytic activity (approximately 10-60-fold) than mononuclear LCl-H-TiOPr2 did. The strategy of bridging dinuclear Ti complexes with isopropoxide groups in the ROP of LA was successful, and adjusting the crowded heptacoordinated transition state by the bridging isopropoxide groups may be the key to our successful strategy.
- Tseng, Hsi-Ching,Chen, Hsing-Yin,Huang, Yen-Tzu,Lu, Wei-Yi,Chang, Yu-Lun,Chiang, Michael Y.,Lai, Yi-Chun,Chen, Hsuan-Ying
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p. 1642 - 1650
(2016/02/27)
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- Ionic liquids as a reusable media for copper catalysis. Green access to alkenes using catalytic olefination reaction
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It was demonstrated that ionic liquids are superb recyclable media for copper catalyzed reactions using catalytic olefination reaction as an example. As a result a novel green access to the halogenoalkenes was elaborated. Possibility to perform up to five reaction cycles without catalyst leaching and decreasing of the yield was demonstrated. A number of various ionic liquids was screened and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim] [BF4]) was found the solvent with highest efficiency. Mild conditions, high atom economy comparing to other known methods, low amounts of wastes and possibility to recover ionic liquid are the advantages of the proposed method.
- Muzalevskiy, Vasily M.,Shastin, Aleksey V.,Shikhaliev, Namiq G.,Magerramov, Abel M.,Teymurova, Aytekin N.,Nenajdenko, Valentine G.
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p. 7159 - 7163
(2016/10/24)
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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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- Synthesis, biological investigation and molecular docking study of N-malonyl-1,2-dihydroisoquinoline derivatives as brain specific and shelf-stable MAO inhibitors
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A group of N-malonyl-1,2-dihydroisoquinoline derivatives were synthesized and investigated as brain specific and shelf-stable MAO inhibitors. N-malonyl-1,2-dihydroisoquinoline redox carrier system was linked through amidic bond to 4-chloro and 4-nitrobenzylidenehydrazines (9a-b), as monoamine oxidase inhibitors (MAOIs), and 2-phenethylamine (14), as a model drug, to afford a novel group of N-malonyl-1,2-dihydroisoquinoline chemical delivery systems (DHIQCDSs) (13a-b and 18). These systems are expected to be stable against air oxidation due to the presence of the carbonyl group close to nitrogen of the dihydroisoquinoline. The synthesized DHIQCDS (18) was subjected to various chemical and biological investigations to evaluate its stability and prove its ability to cross the blood brain barrier and lock-in the brain. The in vitro chemical and enzymatic oxidation studies showed reasonable stability and adequate rate of conversion of DHIQCDS (18) to its corresponding quaternary metabolites. In vivo distribution study in rats revealed preferential concentration of the active moiety in the brain. Moreover, compounds (9a-b, 12a-b and 17) were screened for their in vitro MAO inhibitory activity compared to clorgyline as a reference compound. The inhibition profile was found to be competitive for both MAO-A and MAO-B isozymes with more selectivity toward MAO-A. Molecular docking study of compounds (9a-b, 12a-b and 17) and the suggested metabolites was carried out on both MAO-A and MAO-B isozymes. Observation of the docked poses revealed many interactions with many residues previously reported to have an effect on the inhibition of MAO enzyme.
- Abd El-Gaber, Mohammed K.,Hassan, Hoda Y.,Mahfouz, Nadia M.,Farag, Hassan H.,Bekhit, Adnan A.
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p. 481 - 491
(2015/04/27)
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- Facile synthesis of (E)-β-(trifluoromethyl)styrenes from halothane (HCFC-123B1)
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A practical and convenient synthesis of (E)-β-(trifluoromethyl)styrenes has been achieved by the reaction of commercially available halothane (HCFC-123B1) and hydrazones prepared in advance in situ, in the presence of 1,2-ethylenediamine and a catalytic amount of CuCl2·2H2O at room temperature. The products showed acceptable to high yields and high to excellent stereoselectivity. This handy synthetic method provided easy access to a variety of (E)-β-(trifluoromethyl)styrenes.
- Hirotaki, Kensuke,Kawazoe, Genyu,Hanamoto, Takeshi
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p. 169 - 173
(2015/03/04)
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- A novel one pot multi-component strategy for facile synthesis of 5-aryl-[1,2,4]triazolidine-3-thiones
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We have disclosed an efficient, one pot, novel multi-component approach for the synthesis of 5-aryl-[1,2,4]triazolidine-3-thiones from aldehyde, hydrazine hydrate, and trimethylsilyl isothiocyanate (TMSNCS) in the presence of catalytic amount of sulfamic acid. High yields, easy work-up procedure, no chromatographic separation, and novelty in multi-component strategy are the main merits of the present strategy.
- Mane,Pore
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supporting information
p. 6601 - 6604
(2015/01/09)
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- Synthesis of 2-aryl-5-oxo-4-[2-(phenylmethylidene)hydrazino]-2,5-dihydro- 1H-pyrrole-3-carboxylates by the reaction between hydrazones, acetylenedicarboxylates, and 1-aryl-N,N′-bis(arylmethylidene) methanediamines
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An efficient approach for the preparation of functionalized 2-aryl-2,5-dihydro-5-oxo-4-[2-(phenylmethylidene)hydrazino]-1H-pyrroles is described. The four-component reaction between aldehydes, NH2NH 2×H2O, dialkyl acetylenedicarboxylates, and 1-aryl-N,N′-bis(arylmethylidene)methanediamines proceeds in EtOH under reflux in good-to-excellent yields (Scheme 1). The structures of 4 were corroborated spectroscopically (IR, 1H- and 13C-NMR, and EI-MS, and, in the case of 4f, by X-ray crystallography). A plausible mechanism for this type of reaction is proposed (Scheme 2). Copyright
- Alizadeh, Abdolali,Saberi, Vahid,Mokhtari, Javad
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p. 1991 - 1996
(2013/11/06)
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- A simple one-pot procedure for the synthesis of 1,2,4-triazolo[1,5-a ]pyrid-ines via pseudo five-component reactions catalyzed by molecular iodine
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In this paper we report the synthesis of the 1,2,4-triazolo[1,5-a]pyridine ring system. The reaction between benzylidenehydrazines, dialkyl acetylenedicarboxylates, benzaldehydes, and malononitrile proceeds in EtOH at reflux in the presence of molecular iodine as catalyst in good to excellent yields. Georg Thieme Verlag Stuttgart · New York.
- Alizadeh, Abdolali,Saberi, Vahid,Mokhtari, Javad
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p. 1825 - 1829
(2013/09/12)
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- The synthesis of two new isonitrosoacetophenone derivatives and investigation of their ni(ii), Co(II), Cu(II), and Zr(IV) complexes
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In the present study, two new ligands, 4-chlorobenzal-azino- isonitrosoacetophenone (L1), 4- methylbenzal-azino- isonitrosoacetophenone (L2) and their metal complexes were synthesized using ace- tophenone as a starting material. The
- Ko?ak, Nuriye,Sahin, Mustafa,Ucan, H. Ismet
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p. 1227 - 1231
(2013/01/15)
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- Proteolytic studies in liver homogenate in presence of substituted aryl hydrazones
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Hydrazones of different arylaldehydes were synthesized and their effect on endogenous proteolysis in liver was studied. It was observed that different functional groups on the benzene moiety altered the enzymatic activity and para-nitrobenzaldehyde hydrazone exhibited maximum inhibitory effect.
- Raghav,Singh, Mamta,Kaur, Ravinder,Suman,Priyanka
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experimental part
p. 1409 - 1410
(2012/01/03)
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- Facile method for the conversion of semicarbazones/thiosemicarbazones into azines (Under Microwave Irradiation) and oxadiazoles (By Grinding)
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In an effective transformation, semicarbazones/thiosemicarbazones are smoothly converted into azines under microwave irradition. Oxadiazoles are also obtained from semicarbazones by reaction with bromine generated in situ via a grinding reaction in the solid phase. Taylor &Francis Group, LLC.
- Chattopadhyay, Gautam,Ray, Partha Sinha
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experimental part
p. 2607 - 2614
(2011/08/07)
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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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- Cu and Au nanocomposites in catalytic olefination reaction
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Metal-vapor synthesis-prepared Cu, Ag, Au and bimetallic Au-Cu (optimal) nanocomposites catalyse olefination of hydrazones with polyhalomethanes.
- Nenajdenko, Valentine G.,Vasil'Kov, Alexander Yu.,Goldberg, Aleksey A.,Muzalevskiy, Vasiliy M.,Naumkin, Alexander V.,Podshibikhin, Vladislav L.,Shastin, Aleksey V.,Balenkova, Elizabeth S.
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scheme or table
p. 200 - 202
(2011/03/20)
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- Synthesis and biological activity of some 2-imidazolinylhydrazone derivatives
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A series of N-(imidazolidin-2-ylidene)hydrazones and N-(4,5-dihydro-1H- imidazol-2-yl)-N-methylhydrazones were prepared and examined for α1-, α2-adrenergic and imidazoline I 1, I2 receptors binding affinities as well as cytotoxic activity against human tumor cell lines. Among the compounds tested, 2-naphthaldehyde N-(imidazolidin-2-ylidene)hydrazone (3e) exhibited a significant affinity for both α2-adrenergic and imidazoline I1 receptors (Ki = 94.3 nM and IC50 = 51.7 nM, respectively). Moreover, pyridine-2-carboxaldehyde N-(imidazolidin-2-ylidene) hydrazone (3l) showed the highest binding affinity to α1- adrenoceptors (Ki = 24.6 nM), while quinoline-2-carboxaldehyde N-(imidazolidin-2-ylidene)hydrazone (3m) displayed the highest I2 affinity with a Ki value of 26.7 nM and a high selectivity with respect to α2-adrenergic and imidazoline I1 receptors (Ki = 22470.0 nM and IC50 = 6145.0 nM, respectively). None of the tested N-(4,5-dihydro-1H-imidazol-2-yl)-N- methylhydrazones 4p-u displayed cytotoxic activity.
- Kornicka, Anita,Hudson, Alan L.,Bednarski, Patrick J.
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experimental part
p. 523 - 534
(2010/02/27)
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- Three polymorphs of 4-4′-diiodobenzalazine, and 4-chloro-4′- iodo-benz-alazine
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Three polymorphs of 4,4′-diiodobenzalazine (systematic name: 4-iodo-benzaldehyde azine), C14H10I2N2, have crystallographically imposed inversion symmetry. 4-Chloro-4′-iodobenzalazine [systematic name: 1-(4-chloro-benzyl-idene)-2-(4-iodo-benzyl-idene)diaza
- Ojala, Charles R.,Ojala, William H.,Britton, Doyle,Cramer, Christopher J.
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p. o518-o523
(2008/09/16)
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- Synthesis and Diels-Alder reactions of α-fluoro- and α-trifluoromethylacrylonitriles
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A novel synthetic method for the preparation of α-fluoro- and the still unknown α-trifluoromethylacrylonitriles is elaborated. The reaction of α-fluorovinylbromides and α-trifluoromethylvinylbromides with CuCN leads to the title compounds in good to high yields. While the α-fluoroacrylonitriles were isolated as mixture of Z/E-isomers, the α-trifluoromethylacrylonitriles were obtained as pure Z-isomers. The α-trifluoromethylacrylonitriles are shown to be excellent dienophiles for Diels-Alder reactions.
- Nenajdenko, Valentine G.,Muzalevskiy, Vasiliy M.,Shastin, Aleksey V.,Balenkova, Elizabeth S.,Haufe, Günter
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p. 818 - 826
(2008/03/14)
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- A new synthetic approach to α-chlorocinnamaldehydes
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A new simple and efficient transformation of aromatic aldehydes into α-chlorocinnamaldehydes is described. Catalytic olefination reaction of hydrazones of aromatic aldehydes with 2-trichloromethyl-1,3-dioxolane gives ethylene acetals of target alkenes in moderate to good yields. The reaction proceeds stereoselectively to form preferably Z-isomers.
- Nenajdenko, Valentine G.,Reznichenko, Alexander L.,Lenkova, Olesya N.,Shastin, Alexey V.,Balenkova, Elizabeth S.
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p. 605 - 609
(2007/10/03)
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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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- The catalytic olefination reaction of aldehydes and ketones with CBr 3CF3
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The new approach of catalytic olefination reaction (COR) has been used to convert aromatic and aliphatic aldehydes and ketones to 2-bromo-3,3,3- trifluoroprop-1-enes by the treatment of corresponding hydrazones with CBr 3CF3 under copper(I) catalysis conditions. The reaction proceeds stereoselectively, the target alkenes were obtained in good yields.
- Nenajdenko, Valentine G.,Varseev, Georgy N.,Shastin, Alexey V.,Balenkova, Elisabeth S.
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p. 907 - 913
(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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- New synthetic approach to α-chlorocinnamates: First example of synthesis of functionally substituted alkenes using catalytic olefination reaction
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A new simple and efficient transformation of carbonyl compounds to α-chlorocinnamates is described. Catalytic olefination reaction with ethyl trichloroacetate gives target alkenes in moderate to good yields. The reaction with aromatic aldehydes proceeds stereoselectively to form preferably Z-isomers.
- Nenajdenko, Valentine G.,Lenkova, Olesya N.,Shastin, Alexey V.,Balenkova, Elizabeth S.
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p. 573 - 577
(2007/10/03)
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