- Studies on the reaction of cycloalkanones with malonodinitrile
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Cyclopentanone reacts with malononitrile catalyzed by piperidine or sodium acetate to afford under any case cyclopentylidenemalononitrile dimer: 5-aminospiro-[2,6,7,7a-tetrahydroindene-7,1′-cyclopentane]-4,6,6-tricarbonitrile (7) as the sole product. Contrary to this behavior, cyclohexanone reacts with malononitrile catalyzed by piperidine to afford the analogous cyclohexylidenemalononitrile dimer: 2-aminospiro-[3,4,5,6,7,4a-hexahydronaphthalene-4,1′-cyclohexane]-1,3,3-tricarbonitrile (11); whereas when the reaction is catalyzed by sodium acetate, it afforded 9,10-diaza-8,11-dioxo-tricyclo-[4.3.3.01,6]-dodecane-7,12-dicarbonitrile (12). The structures of these products were established on the basis of their elemental analysis and spectral data, and plausible mechanism has been postulated to account for their formation. X-ray crystallography was carried out as a further evidence for structures 7 and 12.
- Abdelrazek, Fathy M.,Metwally, Nadia H.,Kassab, Nazmi A.,Jaafar, Mohammed T.,Metz, Peter,J?ger, Anne
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- Homogeneous-like solid base catalysts based on pyridine-functionalized swelling porous polymers
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Reported here is the synthesis of pyridine-functionalized porous polymers, which are designed as homogeneous-like base catalysts. These highly porous catalysts have adjustable pyridine contents, high BET surface area (312-649 m2/g), large pore
- Zhang, Yong-Lai,Liu, Sen,Liu, Siyu,Liu, Fujian,Zhang, Haiyan,He, Yinyan,Xiao, Feng-Shou
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- DABCO catalyzed pseudo multi-component synthesis of functionalized spirooxindoles
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Abstract: A direct multi-component assembling of isatin, cyclohexanone, and 2?mol of malononitrile in the presence of catalytic amount of DABCO in aq. ethanol leads to functionalized spirooxindoles at ambient temperature. The novelties of the method are m
- Hegade, Pravin G.,Chinchkar, Sarika D.,Pore, Dattaprasad M.
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- Catalytic performance of a new 1D Cu(II) coordination polymer {Cu(NO3)(H2O)}(HTae)(4,4'-Bpy) for Knoevenagel condensation
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The {Cu(NO3)(H2O)}(HTae)(4,4'-Bpy) (H2Tae = 1,1,2,2-tetraacetylethane, 4,4'-Bpy = 4,4'-Dipyridyl) 1D coordination polymer has been obtained by slow evaporation. The crystal structure consists of parallel and oblique {Cu(HT
- Larrea, Edurne S.,De Luis, Roberto Fernández,Arriortua, María I.
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- Microporous zeolite catalyst system: An eco-approach for regioselective synthesis of pyrimidobenzimidazoles
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Microporous zeolite, having well-defined pore sizes, was found to be most efficient catalyst for regioselective synthesis of pyrimidobenzimidazoles. Different kinds of zeolites were studied as supported microporous material and showed quite different cata
- Arya, Kapil,Tomar, Ravi
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- Ultra-high concentrations of amino group functionalized nanoporous polymeric solid bases: Preparation, characterization and catalytic applications
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We report here that the amino-group functionalized nanoporous polydivinylbenzene (PDVB-2.0-NH2, PDVB-NH2), acts as an efficient solid base for catalyzing Knoevenagel condensation, which could be synthesized from nitration of nanoporo
- Zhang, Bin,Liu, Chen,Wang, Lingjing,Yi, Xianfeng,Zheng, Anmin,Deng, Wenshu,Qi, Chenze,Liu, Fujian
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- Site-specific role of bifunctional graphitic carbon nitride catalyst for the sustainable synthesis of 3,3-spirocyclic oxindoles in aqueous media
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Functionalized graphitic carbon nitride (Sg-C3N4) has been manufactured and used as a reusable catalyst for the one-pot production of various spiro-pyrano chromenes and spiro indole-3,1′-naphthalene tetracyclic systems in aqueous med
- Dandia, Anshu,Mahawar, Dinesh Kumar,Saini, Pratibha,Saini, Surendra,Gupta, Shyam L.,Rathore, Kuldeep S.,Parewa, Vijay
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- Organic reactions in ionic liquids: Gewald synthesis of 2-aminothiophenes catalyzed by ethylenediammonium diacetate
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Ionic liquids based on 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4) and 1-butyl-3-methylimidazolium hexafluorophosphate (BmimPF6) were used as reusable alternatives to volatile organic solvents (VOCs) for ethylenediammonium diacetate (EDDA) catalyzed Gewald synthesis of 2-aminothiophenes. Significant rate enhancement and improvement of the yield were observed. The ionic liquids containing catalyst EDDA were recycled several times with no decreases in yields and reaction rates.
- Hu, Yi,Chen, Zhen-Chu,Le, Zhang-Gao,Zheng, Qin-Guo
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- Water-stable fluorinated metal-organic frameworks (F-MOFs) with hydrophobic properties as efficient and highly active heterogeneous catalysts in aqueous solution
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Two new fluorinated metal-organic frameworks [Zn2(hfipbb)2(4-bpdh)]·0.5DMF (TMU-55) and [Zn2(hfipbb)2(4-bpdb)]·2DMF (HTMU-55) have been solvothermally synthesized by the reaction of two linear N-containing ligan
- Joharian, Monika,Morsali, Ali,Azhdari Tehrani, Alireza,Carlucci, Lucia,Proserpio, Davide M.
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- Interplay between hydrophobicity and basicity toward the catalytic activity of isoreticular MOF organocatalysts
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Due to the structural diversity of metal-organic frameworks, MOFs, tailored engineering of these compounds is important for their use in catalytic processes. Among the MOFs tested as heterogeneous catalysts, there have been rare reports of size selective catalysts. In the present work, we could successfully indicate that subtle substrate selectivity can be induced in the catalytic system by designing a series of isoreticular MOFs with slight structural modifications. Four MOF catalysts possessing imine and/or amine basic N-donor pillars bearing phenyl or naphtyl cores showing different hydrophobic characters around the basic reaction center were prepared via a simple mechano-chemical synthesis. They were characterized thoroughly using TG, IR and PXRD analysis. For the first time, the aldol-type condensation reaction of malononitrile with ketone-functionalized carbonyl substrates was developed in the presence of the basic MOF organocatalysts. Moreover, it has been successfully shown that a subtle substrate selectivity can be addressed during the reaction of three slightly different α,β-unsaturated carbonyl compounds in contrast to the effect of size control barriers that commonly direct a heterogeneous reaction pathway.
- Abedi, Sedigheh,Azhdari Tehrani, Alireza,Ghasempour, Hosein,Morsali, Ali
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- Asymmetric organocatalytic vinylogous Michael addition triggered triple-cascade reactions of 2-hydroxycinnamaldehydes and vinylogous nucleophiles: construction of benzofused oxabicyclo[3.3.1]nonane scaffolds
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An organocatalytic vinylogous Michael addition triggered triple-cascade reaction has been developed. 2-Hydroxycinnamaldehydes worked under iminium activation with either acyclic or cyclic ketone-derived α,α-dicyanoalkenes, yielding the benzofused oxabicyclo[3.3.1]nonanes bearing one quaternary stereocenter with excellent stereoselectivities.
- Wu, Hui-Chun,Wang, Chen,Chen, Ying-Han,Liu, Yan-Kai
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supporting information
p. 1762 - 1765
(2021/02/27)
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- An Ionic Liquid on a Porous Organic Framework Support: A Recyclable Catalyst for the Knoevenagel Condensation in an Aqueous System
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Porous aromatic frameworks (PAFs) that feature a high density of phenyl rings in their robust frameworks are attractive platforms for catalysis because of their extremely high stability, high surface area, and adjustable pore size. In this paper, two PAF-
- Chen, Peng,Sun, Jin-Shi,Wu, Xian-Tao,Xiao, En-Kai,Zhang, Lei,Zhu, Guangshan
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p. 943 - 947
(2020/06/01)
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- Synthesis of 1H-isochromenes, 4H-chromenes, and ortho-aminocarbonitrile tetrahydronaphthalenes from the same reactants by using metal-free catalyst
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A facile and rapid multicomponent synthesis of pharmaceutically diverse 1H-isochromenes, 4H-chromenes, and ortho-aminocarbonitrile tetrahydronaphthalenes has been developed from benzaldehyde, malononitrile, and cyclohexanone. Three different methods from the same reactants, solvent, temperature, and catalyst lead to three products with excellent yields. All the reactions were followed with the Michael addition and cyclization. In this study, morpholine was used as an active metal-free base catalyst that increases the yields of products and decreases the time of reactions.
- Naeimi, Hossein,Mohammadi, Somaye
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supporting information
p. 50 - 59
(2019/12/27)
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- Knoevenagel condensation reaction on a new highly-efficient La2O2CO3-TiO2 mixed oxide catalyst: Composition-effects on C[dbnd]C bond formation
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The highly efficient catalytic abilities of some mixed oxides are due to cooperative interactions between acid and base functional groups present in their active sites. New La2O2CO3-TiO2 mixed oxide catalysts wi
- Wang, Fei,Hu, Kai,Bi, Yanshuai,Wei, Xuejiao,Xue, Bing
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- Method used for preparing substituted 1, 3-malononitrile
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The invention belongs to the field of fine chemical product preparation and medicine intermediate synthesis, and relates to a method used for preparing substituted 1, 3-malononitrile. According to themethod, an aldehyde or a ketone and malononitrile are subjected to condensation reaction to prepare substituted 1, 3-malononitrile, wherein water is taken as a solvent, the aldehyde or the ketone andmalononitrile are subjected to Knoevenagel condensation under catalytic effect of zinc proline so as to obtain the corresponding substituted 1, 3-malononitrile. The method conditions are mild; operation is convenient; water is taken as a reaction solvent, so that the method is friendly to the environment; and the application prospect is promising.
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Paragraph 0040-0041
(2019/08/07)
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- Methods and compositions for terpenoid tricycloalkane synthesis
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In one aspect, the disclosure relates to methods for preparation of intermediates useful for the preparation of terpenoid cores. In a further aspect, the disclosed methods pertain to the preparation of compounds comprising a terpenoid core or scaffold, su
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Page/Page column 48; 53; 84; 85
(2019/05/26)
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- Prolinamide functionalized polyacrylonitrile fiber with tunable linker length and surface microenvironment as efficient catalyst for Knoevenagel condensation and related multicomponent tandem reactions
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A series of new prolinamide polyacrylonitrile fiber catalysts with tunable length of alkyl linker and different linker group were prepared by covalent bonding for the first time and well characterized by mechanical strength, FT-IR, XRD, EA, TGA, SEM and water contact angel. The catalytic activities of these fiber catalysts were evaluated in Knoevenagel condensation and one-pot Knoevenagel-Michael multicomponent tandem reactions to synthesize α, β-unsaturated nitrile and 2-amino-4H-chromene derivatives in water. The result show that the suitable linker length attaching amines to fiber matrix as well as the constructed hydrophobic microenvironment by linker group within the surface layers of fiber materials effectively promotes the reactions. In addition, the good swollen capacity of fiber in solvent ensure that the reaction proceed well. Fiber catalyst PANPA?2F modified by prolinamide with a C2 alkyl chain exhibited the best catalytic performance and can be easily recovered and reused for at least ten consecutive cycles without significant loss of catalytic activity and active sites leaching.
- Zhu, Hai,Xu, Gang,Du, Huimin,Zhang, Chenlu,Ma, Ning,Zhang, Wenqin
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p. 217 - 229
(2019/05/16)
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- Amino Acid Amide based Ionic Liquid as an Efficient Organo-Catalyst for Solvent-free Knoevenagel Condensation at Room Temperature
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Abstract: Ionic liquids of amino acid amide were synthesized and used as an efficient catalyst for solvent-free Knoevenagel condensation. Synthesized ionic liquids are an environmentally benign, inexpensive, metal free and plays the dual role of solvent as well as an efficient catalyst for Knoevenagel condensation. A wide range of aliphatic, aromatic and heteroaromatic aldehydes easily undergo condensation with malononitrile and ethyl cyanoacetate. The reaction proceeds at room temperature without using any organic solvent and is very fast with good to excellent yield. Additionally, the catalyst is easily separable and recyclable without loss of activity. Graphic Abstract: [Figure not available: see fulltext.].
- Burate, Pralhad A.,Javle, Balasaheb R.,Desale, Pranjal H.,Kinage, Anil K.
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p. 2368 - 2375
(2019/06/17)
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- Organocatalytic asymmetric vinylogous 1,4-addition of α,α-Dicyanoolefins to chalcones under a bio-based reaction media: Discovery of new Michael adducts with antiplasmodial activity
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The organocatalysed asymmetric vinylogous Michael addition of α,α-dicyanoolefins to α,β-unsaturated aldehydes and ketones have been reported in the last decade, however, chalcones have been poorly explored. Moreover, a considerable part of the publications in this theme still employs undesirable solvents, such as toluene and THF, with concerns related to health and environmental safety. We report herein the use of a bifunctional catalyst derived from a Cinchona alkaloid to perform the enantio- and diastereoselective Michael addition of α,α-dicyanoolefins to chalcones using 2-MeTHF as solvent. The Michael adducts were obtained in moderate to good yields and were evaluated for their antiplasmodial and cytotoxic activity.
- Martelli, Lorena S.R.,Vieira, Lucas C.C.,Paix?o, Márcio W.,Zukerman-Schpector, Julio,de Souza, Juliana O.,Aguiar, Anna Caroline C.,Oliva, Glaucius,Guido, Rafael V.C.,Corrêa, Arlene G.
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supporting information
p. 3530 - 3542
(2019/05/24)
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- Synthesis of 2-cyanoacrylamides through Pd-catalyzed monohydration of methylenemalononitriles
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A straightforward and efficient method has been developed for the synthesis of 2-cyanoacrylamide from 2-methylenemalononitriles through monohydration. A series of methylenemalononitriles underwent the reaction under mild and simple reaction conditions wit
- Liu, Yingtian,Dang, Xinxin,He, Yu,Bai, Hudong,Chen, Xuehong,Li, Jun-Long,Fan, Junting,Jiang, Hezhong,Li, Jiahong
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p. 662 - 671
(2019/02/20)
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- Synthesis of Novel Pterocarpen Analogues via [3?+?2] Coupling-Elimination Cascade of α,α-Dicyanoolefins with Quinone Monoimines
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By employing triethylamine as a catalyst, [3?+?2] coupling-elimination cascade of α,α-dicyanoolefins with quinone monoimines was realized. The reactions afforded various novel pterocarpen analogues with generally moderate yields (up to 75%). In addition, a plausible reaction mechanism was proposed.
- Chen, Hui,Zhao, Sihan,Cheng, Shaobing,Dai, Xingjie,Xu, Xiaoying,Yuan, Weicheng,Zhang, Xiaomei
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p. 1672 - 1683
(2019/04/08)
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- Co2+ immobilized on highly ordered mesoporous graphitic carbon nitride (ompg-C3N4/Co2+) as an efficient and recyclable heterogeneous catalyst for one-pot tandem selective photo-oxidation/Knoevenagel condensation
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Design and synthesis of efficient heterogeneous photocatalysts is an important task for practical applications due to the increasing environmental challenges and energy crisis. In this work, Co2+ modified highly ordered mesoporous graphitic carbon nitride (ompg-C3N4/Co2+) was prepared through a simple procedure involving sonication treatment. The obtained catalyst was characterized using FT-IR, XRD, ICP-OES, FE-SEM, UV–vis DRS, N2 adsorption-desorption, and TGA. It was found that the ompg-C3N4/Co2+ can function as a multifunctional heterogeneous photocatalyst for the one-pot tandem selective photo-oxidation/ Knoevenagel condensation. More interestingly, the obtained ompg-C3N4/Co2+ represented a high photocatalytic activity in benzyl alcohol oxidation without any oxidant under air atmosphere and visible light irradiation.
- Ghafuri, Hossein,Jafari, Ghazaleh,Rashidizadeh, Afsaneh,Manteghi, Faranak
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- Molybdenum carbide as an efficient and durable catalyst for aqueous Knoevenagel condensation
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By following green chemistry principles, various molybdenum compounds as cost-effective, commercially available, heterogeneous, and benign catalysts were used for the Knoevenagel condensation reaction. Among the compounds (Mo2C, MoS2, MoB, MoSi2), molybdenum carbide showed efficient performance for the Knoevenagel condensation in aqueous media at room temperature, affording the corresponding products in high yields within a short reaction time. Notably, using this commercially available heterogeneous catalyst, the deacetalization-Knoevenagel condensation of benzaldehyde dimethyl acetal and malononitrile at room temperature could successfully proceed in excellent yield. Molybdenum carbide could be recovered five times without loss of activity with an operationally simple procedure.
- Tavakolian, Mina,Najafpour, Mohammad Mahdi
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p. 16437 - 16440
(2019/11/11)
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- Synthesis method of methylene malononitrile compounds
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The invention discloses a synthesis method of methylene malononitrile compounds. According to the method, in the air atmosphere, a ketone compound and malononitrile are taken as raw materials, Ru/C istaken as a catalyst, the raw materials and the catalyst
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Paragraph 0029-0033; 0059-0062
(2020/04/02)
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- Nmp-based ionic liquids: Recyclable catalysts for both hetero-Michael addition and Knoevenagel condensation in water
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A series of novel N-methyl piperidine (Nmp)-based ionic liquids with 1,2-propanediol group are synthesized and used as catalysts for both hetero-Michael addition of α,β-unsaturated amides and Knoevenagel condensation at room temperature in water; and all the examined substrates could be transformed into corresponding products in good to excellent yields. Meanwhile IL-catalyzed hetero-Michael addition of α,β-unsaturated amides in water has not been reported in the previous literatures. Additionally, the catalyst is recyclable for the two reactions. This finding provides a green catalyst for both hetero-Michael addition of α,β-unsaturated amides and Knoevenagel condensation in water.
- Yang, Pengkun,Liu, Yawei,Chai, Ling,Lai, Zhenzhen,Fang, Xiaomin,Liu, Baoying,Zhang, Wenkai,Lu, Minghua,Xu, Yuanqing,Xu, Hao
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supporting information
p. 1060 - 1067
(2018/05/23)
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- Complex Hydroindoles by an Intramolecular Nitrile-Intercepted Allylic Alkylation Cascade Reaction
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Bisnucleophilic reagents derived from malononitrile, ketones, benzaldehydes, and nitromethane can react with bisallylic electrophiles via a nitrile-intercepted allylic alkylation cascade reaction to yield complex hydroindole architectures. Also noteworthy
- Vertesaljai, Peter,Ghiviriga, Ion,Grenning, Alexander J.
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supporting information
p. 1970 - 1973
(2018/04/16)
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- Polyoxoniobates as a superior Lewis base efficiently catalyzed Knoevenagel condensation
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The outstanding basicity of negative charged Lindqvist type Polyoxoniobate K7HNb6O19·13H2O (Nb6) have been proved experimentally as well as by theoretical NBO calculations, the results insights high electron density on terminal and bridging oxygen atoms of niobate anion. The most negative Natural Bond Orbital charge (NBO) of oxygen in Nb6 is ?1.001, which is a much more negative value than those reported in other polyoxometalates, that corroborates its high basicity thus likely to be employed as a strong base catalyst. Experimental study suggests that Nb6 can efficiently catalyze Knoevenagel condensation of various carbonyl compounds with active methylene compounds neglecting the steric and electronic effect of aromatic aldehydes under mild conditions. Kinetic test shows that Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate exhibits second-order kinetics in the presence of Nb6 and the calculated activation energy is 43.3 kJ mol?1. Meanwhile, a proper mechanism according to the NBO study speculates that the most negative charged terminal oxygens in Nb6 would be pivotal in this transformation.
- Xu, Qiaofei,Niu, Yanjun,Wang, Guan,Li, Yingguang,Zhao, Yuan,Singh, Vikram,Niu, Jingyang,Wang, Jingping
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- An Enyne Cope Rearrangement Enables Polycycloalkane Synthesis from Readily Available Starting Materials
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Cyclohexanone-derived Knoevenagel adducts (cyclohexylidenemalononitriles) and two different propargyl electrophiles serve as carbon sources for assembling diverse 6/7/5 tricycloalkanes, a common terpenoid framework. The sequence involves three unique reac
- Scott, Sarah K.,Grenning, Alexander J.
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supporting information
p. 8125 - 8129
(2017/06/30)
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- Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water
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A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.
- Xu, Hao,Pan, Liyang,Fang, Xiaomin,Liu, Baoying,Zhang, Wenkai,Lu, Minghua,Xu, Yuanqing,Ding, Tao,Chang, Haibo
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supporting information
p. 2360 - 2365
(2017/05/29)
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- Knoevenagel Condensation of Aldehydes and Ketones with Malononitrile Catalyzed by Amine Compounds-Tethered Fe3O4@SiO2 Nanoparticles
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Abstract: A new magnetic nanoparticle supported-catalyst was developed for the Knoevenagel condensation between malononitrile and several aldehydes. The Fe3O4@SiO2-3N (where 3N = N1-(3-trimethoxysilylpropyl)diet
- de Resende Filho, Jo?o Batista M.,Pires, Gilvan P.,de Oliveira Ferreira, Jo?o Marcos Gomes,Teotonio, Ercules E. S.,Vale, Juliana A.
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p. 167 - 180
(2017/02/10)
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- Three-component synthesis of 5-aryl-3-amino-1H-pyrazole-4-carbonitriles and 3-amino-1,2-diazaspiro[4.5]dec-3-ene-4-carbonitriles
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A multicomponent method of the synthesis of 5-aryl-3-amino-1H-pyrazole-4-carbonitrile and 3-amino-1,2-diazaspiro[4.5]dec-3-ene-4-carbonitriles with thermal and microwave activation was developed.
- Ivonin,Bychok, O. Yu.,Safarova,Sorokin
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p. 2477 - 2480
(2017/11/24)
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- Tungstate-loaded triazine-based magnetic poly(Bis-imidazolium ionic liquid): An effective bi-functional catalyst for tandem selective oxidation/Knoevenagel condensation in water
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A novel bi-functional polymeric catalyst was synthesized by immobilization of tungstate anions onto the nitrogen rich poly(ionic liquid)/magnetic nanocomposite. The resulting catalyst has two types of catalytic sites: (i) immobilized WO4 anions with bis-imidazolium ionic liquid cation for selective oxidation of alcohols and (ii) basic amine groups for Knoevenagel condensation between produced aldehyde and malononitrile. Due to the polymeric nature of the catalyst, large amounts of tungstate and basic nitrogen groups were presented on the solid surface which led to a decrease in the applied catalyst mass for catalytic reaction. High catalytic activity and excellent selectivity of catalyst in water medium make this protocol a green way for production of fine chemicals.
- Zohreh, Nasrin,Tavakolizadeh, Maryam,Hosseini, Seyed Hassan,Pourjavadi, Ali,Bennett, Craig
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p. 342 - 350
(2017/02/19)
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- Assembly of Terpenoid Cores by a Simple, Tunable Strategy
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Oxygenated, polycyclic terpenoid natural products have important biological activities. Although total synthesis of such terpenes is widely studied, synthetic strategies that allow for controlled placement of oxygen atoms and other functionality remains a challenge. Herein, we present a simple, scalable, and tunable synthetic strategy to assemble terpenoid-like polycycloalkanes from cycloalkanones, malononitrile, and allylic electrophiles, abundantly available reagent classes.
- Lahtigui, Ouidad,Emmetiere, Fabien,Zhang, Wei,Jirmo, Liban,Toledo-Roy, Samira,Hershberger, John C.,Macho, Jocelyn M.,Grenning, Alexander J.
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supporting information
p. 15792 - 15796
(2016/12/16)
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- Organocatalyzed asymmetric 1,6-conjugate addition of para-quinone methides with dicyanoolefins
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A chiral thiourea catalyzed asymmetric 1,6-conjugate addition of para-quinone methides with dicyanoolefins has been developed. The reaction provided an efficient approach to the synthesis of chiral diarylmethine skeletons in good yields (up to 99% yield) with high diastereo- and enantioselectivity (>20:1 dr and up to 99.5:0.5 er), also on a gram scale. The preliminary mechanistic study showed that the remote stereocontrol was achieved through intermolecular hydrogen-bond interaction between the chiral thiourea catalyst and the para-quinone methides directly for the first time.
- Li, Xuanyi,Xu, Xiuyan,Wei, Weiwei,Lin, Aijun,Yao, Hequan
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supporting information
p. 428 - 431
(2016/02/19)
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- Sterically Demanding Oxidative Amidation of α-Substituted Malononitriles with Amines Using O2
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An efficient amidation method between readily available 1,1-dicyanoalkanes and either chiral or nonchiral amines was realized simply with molecular oxygen and a carbonate base. This oxidative protocol can be applied to both sterically and electronically challenging substrates in a highly chemoselective, practical, and rapid manner. The use of cyclopropyl and thioether substrates support the radical formation of α-peroxy malononitrile species, which can cyclize to dioxiranes that can monooxygenate malononitrile α-carbanions to afford activated acyl cyanides capable of reacting with amine nucleophiles.
- Li, Jing,Lear, Martin J.,Hayashi, Yujiro
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supporting information
p. 9060 - 9064
(2016/07/26)
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- Fluorous bispidine: A bifunctional reagent for copper-catalyzed oxidation and knoevenagel condensation reactions in water
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Fluorous bispidine-type ligands have been developed to facilitate its recovery and reusability and to demonstrate its bifunctional property as a ligand and base in copper-catalyzed aerobic oxidation, the Knoevenagel condensation and tandem oxidation/Knoevenagel condensation in water under mild conditions. Application of the fluorous ligand was also extended to the surfactant-free copper-catalyzed allylic and benzylic sp3 C-H oxidation reaction in water. The fluorous ligands could be recovered using F-SPE with recovery ranging from 91-97% and could be reused five times with little loss of activity.
- Ang, Wei Jie,Chng, Yong Sheng,Lam, Yulin
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p. 81415 - 81428
(2015/10/06)
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- Mixed Metal-Organic Framework as a Heterogeneous Catalyst
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The synthesis of a new mixed metal-organic framework (M′MOF) has been accomplished by the metalloligand approach. [NaCu(2,4-HPdc)(2,4-Pdc)] (2,4-H2Pdc = pyridine-2,4-dicarboxylic acid) has been obtained from the hydrothermal reaction of the metalloligand [Cu(2,4-HPdc)2(H2O)2] NaOH, and a transition metal salt. [NaCu(2,4-HPdc)(2,4-Pdc)] is isostructural to [CuMn(2,4-Pdc)2] and crystallizes in the triclinic space group Pβar {1}$. The 3D structure is built up from [Cu(2,4-HPdc)2(H2O)2] metalloligands and [NaO6] octahedra in a pcu α-Po-like uninodal six-connected net. The compound is stable to 290 °C, and its crystal structure undergoes a 3 % volume expansion between room temperature and thermal decomposition. The unsaturated CuII centers at the surface act as a heterogeneous Lewis acid catalyst for the cyanosilylation of aldehydes and Knoevenagel C-C bond-forming reactions. The catalytic activity has been compared with those of other copper(II) porous metal-organic frameworks such as HKUST-1 and MOF-74.
- Larrea, Edurne S.,Fernández De Luis, Roberto,Orive, Joseba,Iglesias, Marta,Arriortua, María I.
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p. 4699 - 4707
(2015/10/19)
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- Classical Keggin Intercalated into Layered Double Hydroxides: Facile Preparation and Catalytic Efficiency in Knoevenagel Condensation Reactions
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The family of polyoxometalate (POM) intercalated layered double hydroxide (LDH) composite materials has shown great promise for the design of functional materials with numerous applications. It is known that intercalation of the classical Keggin polyoxome
- Jia, Yueqing,Fang, Yanjun,Zhang, Yingkui,Miras, Haralampos N.,Song, Yu-Fei
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supporting information
p. 14862 - 14870
(2015/10/20)
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- Tri-lacunary polyoxometalates of Na8H[PW9O 34] as heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation and the synthesis of benzoxazole derivatives
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We reported for the first time the development of tri-lacunary polyoxometalates (POMs) of Na8H[A-PW9O34] ·7H2O and Na8H[B-PW9O 34]·19H2O (Na-A-PW9 and Na-B-PW 9) as highly selective and efficient heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation of various aldehydes and ketones and the synthesis of benzoxazole derivatives at 25 C under mild conditions. Since both Na-A-PW9 and Na-B-PW9 display no characteristic porosity, it is proposed that the catalytic reactions proceed not only on the surface and interface, but also in the bulk phase. The catalysts can be easily recovered and reused for at least six times without obvious decrease of catalytic activities and the structures of the catalysts remain unchanged after recycling. The easy preparation, high efficiency, reusability of the heterogeneous catalysts of Na-A-PW9 and Na-B-PW9 exhibit great potential for further application.
- Zhao, Shen,Chen, Yang,Song, Yu-Fei
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p. 140 - 146
(2014/03/21)
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- Gas uptake, molecular sensing and organocatalytic performances of a multifunctional carbazole-based conjugated microporous polymer
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A multifunctional carbazole-based conjugated microporous polymer MFCMP-1 is successfully prepared by oxidative coupling polymerization using a single monomer and structurally characterized. A new three-dimensional π-conjugated polymer framework can be com
- Zhang, Yuwei,Sigen,Zou, Yongcun,Luo, Xiaolong,Li, Zhongping,Xia, Hong,Liu, Xiaoming,Mu, Ying
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p. 13422 - 13430
(2014/08/18)
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- Synthesis of methyl 3-azidothieno[2,3-b]pyridine-2-carboxylates and application of the huisgen reaction
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The preparation of new substituted methyl 3-azidothieno[2,3-b]pyridine carboxylates by azotization of methyl 3-aminothieno[2,3-b]pyridine and subsequent treatment with sodium azide is described. Via Huisgen's 1,3-dipolar cycloaddition between substituted alkynes and the prepared azides, methyl 1,2,3-triazolo-thieno[2,3-b]pyridine carboxylates have been obtained.
- Chaouni, Wafaa,Aadil, Mina,Djellal, Ahmed,Kirsch, Gilbert
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p. 509 - 518
(2014/06/10)
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- Aqueous DABCO, an efficient medium for rapid organocatalyzed Knoevenagel condensation and the Gewald reaction
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In the presence of water and 1,4-diazabicyclo[2.2.2]octane, several aldehydes and cyclic ketones underwent efficient Knoevenagel condensation with malononitrile and ethyl cyanoacetate to produce the respective α.β-unsaturated systems within fairly short time periods. As a result, high yields of conjugated products were easily obtained. Products could be engaged in a Gewald reaction, either stepwise or in situ, to produce efficiently their respective 2-aminothiophenes within 4-7 h. TUeBITAK.
- Abaee, Mohammad Saeed,Cheraghi, Somayeh
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p. 650 - 660
(2014/07/07)
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- A porphyrin-linked conjugated microporous polymer with selective carbon dioxide adsorption and heterogeneous organocatalytic performances
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A new porphyrin-based conjugated microporous polymer with rich nitrogen sites in the skeleton has been synthesized by alkyne-alkyne homocoupling reaction. The Brunauer-Emmett-Teller specific surface area up to 662 m 2 g-1 was obtaine
- Liu, Xiaoming,A, Sigen,Zhang, Yuwei,Luo, Xiaolong,Xia, Hong,Li, He,Mu, Ying
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p. 6447 - 6453
(2014/02/14)
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- Synthesis and bioactivity of novel amino-pyrazolopyridines
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Here we describe the synthesis and biological activity of novel amino-pyrazolopyridines with anti-NF-κB and pro-apoptotic potential. α-Methylene ketones were used as a starting point for synthesis of amino-pyrazolopyridine 3. The alkylidene malononitriles 1 were obtained by the Knoevenagel reaction of ketones with malononitriles. Vilsmeier-Haack reaction allowed direct access to 2-chloro-3-cyanopyridines 2. Those products, by refluxing with hydrazine hydrate, allowed cyclization to amino-pyrazolopyridines 3a-g, which were not previously described in the literature. Bioactivity results indicated that amino-pyrazolopyridines 3a, 3b and 3g induced apoptotic cell death in K562 cancer cells with an IC50 of 36.5 ± 3.9 μM, 27.6 ± 4.5 μM and 35.0 ± 2.3 μM, respectively, after 72 h. In addition, compounds 3a, 3b and 3g exerted NF-κB inhibition activity with an IC50 of 4.7 ± 1.6 μM, 6.9 ± 1.9 μM and 39.8 ± 3.9 μM, respectively, after 8 h in K562 cells activated with TNFα. Compounds 3b and 3g showed interesting differential toxicity as viability of peripheral blood mononuclear cells (PBMCs) from healthy donors remained largely unaffected by this treatment.
- Orlikova, Barbora,Chaouni, Wafaa,Schumacher, Marc,Aadil, Mina,Diederich, Marc,Kirsch, Gilbert
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p. 450 - 457
(2014/09/03)
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- Lipase-catalyzed highly diastereoselective direct vinylogous Michael addition reaction of α,α-dicyanoolefins to nitroalkenes
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Lipase-catalyzed direct vinylogous Michael addition reactions of electron-deficient vinyl malononitriles to nitroalkenes are reported for the first time. A series of nitroalkenes reacting with vinyl malononitriles generate the corresponding products with
- Zhou, Long-Hua,Wang, Na,Chen, Guan-Nan,Yang, Qi,Yang, Sheng-Yong,Zhang, Wei,Zhang, Yang,Yu, Xiao-Qi
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supporting information
p. 170 - 177
(2014/12/11)
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- Metal-dioxidoterephthalate MOFs of the MOF-74 type: Microporous basic catalysts with well-defined active sites
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The hybrid frameworks M2dobdc (dobdc4- = 2,5-dioxidoterephthalate, M2+ = Mg2+, Co2+, Ni2+, Cu2+ and Zn2+), commonly known as CPO-27 or MOF-74, are shown to be active catalysts in base-catalyzed reactions such as Knoevenagel condensations or Michael additions. Rather than utilizing N-functionalized linkers as a source of basicity, the intrinsic basicity of these materials arises from the presence of the phenolate oxygen atoms coordinated to the metal ions. The overall activity is due to a complex interplay of the basic properties of these structural phenolates and the reactant binding characteristics of the coordinatively unsaturated sites. The nature of the active site and the order of activity between the different M 2dobdc materials were rationalized via computational efforts; the most active material, both in theory and in experiment, is the Ni-containing variant. The basicity of Ni2dobdc was experimentally proven by chemisorption of pyrrole and observation by IR spectroscopy.
- Valvekens, Pieterjan,Vandichel, Matthias,Waroquier, Michel,Van Speybroeck, Veronique,De Vos, Dirk
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- Base catalytic activity of alkaline earth MOFs: A (micro)spectroscopic study of active site formation by the controlled transformation of structural anions
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A new method has been developed for generating highly dispersed base sites on metal-organic framework (MOF) lattices. The base catalytic activity of two alkaline earth MOFs, M2(BTC)(NO3)(DMF) (M = Ba or Sr, H3BTC = 1,3,5-benzenetricarboxylic acid, DMF = N,N-dimethylformamide) was studied as a function of their activation procedures. The catalytic activity in Knoevenagel condensation and Michael addition reactions was found to increase strongly with activation temperature. Physicochemical characterization using FTIR, 13C CP MAS NMR, PXRD, XPS, TGA-MS, SEM, EPR, N2physisorption and nitrate content analysis shows that during activation, up to 85% of the nitrate anions are selectively removed from the structure and replaced with other charge compensating anions such as O2-. The defect sites generated via this activation act as new strong basic sites within the catalyst structure. A fluorescence microscopic visualization of the activity convincingly proves that it is exclusively associated with the hexagonal crystals, and that reaction proceeds inside the crystal's interior. Theoretical analysis of the Ba-material shows that the basicity of the proposed Ba2+-O2--Ba2+motifs is close to that of the edge sites in BaO. This journal is
- Valvekens,Jonckheere,De Baerdemaeker,Kubarev,Vandichel,Hemelsoet,Waroquier,Van Speybroeck,Smolders,Depla,Roeffaers,De Vos
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p. 4517 - 4524
(2015/02/19)
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- Polystyrene-immobilized DABCO as a highly efficient and recyclable organocatalyst for the Knoevenagel condensation reaction
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Polystyrene-immobilized DABCO was used for the first time as a basic organocatalyst for carbon-carbon bond formation reactions. The supported catalyst could be used as a reusable catalyst in the Knoevenagel condensation of a wide range of aromatic/heterocyclic/α,β-unsaturated aldehydes and ketones with active methylene compounds. The reaction conditions are mild and the method is operationally simple. The reactions proceed in a short time period and with 100% selectivity. The catalyst could be easily separated from the reaction by filtration and recycled ten times without activity loss. Based on the catalyst, a continuous flow process was also developed.
- Xu, Da-Zhen,Shi, Sen,Wang, Yongmei
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p. 23075 - 23079
(2013/11/19)
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- Molybdenum hexacarbonyl-catalyzed condensation of malononitrile with ketones and aldehydes
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Molybdenum hexacarbonyl activated with pyridine or morpholine catalyzes the condensation of malononitrile with ketones and aldehydes at 140 C, which leads to alkylidenemalononitriles in 75-100% yield.
- Khusnutdinov,Shchadneva,Mayakova,Oshnyakova,Dzhemilev
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p. 683 - 686
(2014/01/23)
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- A simple, efficient and green procedure for Knoevenagel condensation in water or under solvent-free conditions
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1,4-Diazabicyclo[2.2.2]octane was used as an efficient catalyst in the Knoevenagel condensation reaction of various kinds of aromatic/aliphatic/ heterocyclic/α,β-unsaturated aldehydes and ketones with active methylene compounds. This is a convenient and rapid method for Knoevenagel condensation, which affords the corresponding substituted electrophilic alkenes in excellent yields. The reaction condition is mild and the method is operationally simple. The products, only E-isomers were detected, did not need to be purified. The use of water as the reaction mediummakes the process environmentally benign. The catalysts can be recycled six times without activity loss.
- Yu, Ya-Qin,Wang, Zhong-Liang
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p. 288 - 292
(2013/07/27)
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- Improved synthesis of mono- and disubstituted 2-halonicotinonitriles from alkylidene malononitriles
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Pyridines with 2,3,4 and/or 5 substitution remain challenging to prepare. Existing strategies to form multisubstituted 2-halonicotinonitriles via enamines suffer from dimerization of the starting alkylidene malononitriles resulting in low yields. Through alteration of reaction conditions, a new high yielding method into enamines was realized by condensing DMF-DMA and alkylidene malononitriles in the presence of substoichiometric acetic anhydride. Cyclization of the resulting enamines under Pinner conditions provided 2-halonicotinonitriles in high overall yields.
- Longstreet, Ashley R.,Campbell, Brian S.,Gupton, B. Frank,McQuade, D. Tyler
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supporting information
p. 5298 - 5301
(2013/11/06)
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- One-pot multistep cascade reactions over multifunctional nanocomposites with pd nanoparticles supported on amine-modified mesoporous silica
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Two kinds of multifunctional nanocomposites, SBA-15-NH2/Pd-p and SBA-15-NH2/Pd-f, with platelet-like and fiber-like morphologies, respectively, were fabricated by immobilizing Pd NPs onto amine-functionalized SBA-15. Some of the amino groups acted as anchoring sites for Pd NPs, whilst the remaining groups acted as Bronsted basic sites. As a result, the composites served as excellent multifunctional heterogeneous catalysts for one-pot multistep cascade reaction sequences. Moreover,when diffusion was the rate-determine step, SBA-15-NH2/Pd-p, with small mesopores, was superior to the fiber-like control sample, owing to its short diffusion length, a lower possibility of pore clogging, and better mass transportation for the reaction species during the catalysis.
- Li, Ping,Liu, Hua,Yu, Yu,Cao, Chang-Yan,Song, Wei-Guo
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p. 2459 - 2465
(2013/10/08)
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