- Synthesis of lithium/cesium-Zagronas from zagrosian natural asphalt and study of their activity as novel, green, heterogeneous and homogeneous nanocatalysts in the Claisen–Schmidt and Knoevenagel condensations
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A novel, heterogeneous and homogeneous basic nanocatalysts were synthesized by grafting of lithium and cesium on zagrosian natural asphalt sulfonate (Li/Cs-Zagronas). The activity of these catalysts was examined in the Claisen–Schmidt and Knoevenagel condensations under mild reaction conditions. Li/Cs-Zagronas were characterized by FT-IR spectroscopy, scanning electron microscopy, X-ray diffraction, energy-dispersive spectroscopy, inductively coupled plasma and thermogravimetric analysis techniques. These nanocatalysts were removed by simple filtration and reused several times without any deterioration of activity.
- Soleiman-Beigi, Mohammad,Ghalavand, Saba,Venovel, Hadis Gholami,Kohzadi, Homa
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p. 3267 - 3279
(2021/06/17)
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- Green, rapid, and highly efficient syntheses of α,α′-bis[(aryl or allyl)idene]cycloalkanones and 2-[(aryl or allyl)idene]-1-indanones as potentially biologic compounds via solvent-free microwave-assisted Claisen–Schmidt condensation catalyzed by MoCl5
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A new, green, and highly efficient protocol for the expeditious preparation of some α,α′-bis[(aryl or allyl)idene]cycloalkanones and 2-[(aryl or allyl)idene]-1-indanones via a simple microwave-assisted Claisen–Schmidt condensation reaction catalyzed by MoCl5 was successfully developed. Outstanding features of the current methodology include the use of solvent-free conditions, simple operation, use of a very inexpensive and available catalyst, low catalyst loading, short reaction times, high yields of the pure products, no harmful by-products, easy workup, and also the applicability of microwave irradiation as a clean source of energy. Furthermore, a gram-scale reaction was successfully conducted, proving the scalability of this current Claisen–Schmidt condensation reaction.
- Bakhshi, Reza,Zeynizadeh, Behzad,Mousavi, Hossein
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p. 623 - 637
(2019/08/26)
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- Potassium Natural Asphalt Sulfonate (K-NAS): Synthesis and characterization as a new recyclable solid basic nanocatalyst and its application in the formation of carbon–carbon bonds
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In this research, we synthesized and characterized a new heterogeneous basic nanocatalyst and its catalytic application was studied in the Claisen-Schmidt and Knoevenagel condensations. In order to prepare this nanocatalyst, first, the Iranian natural asphalt was sulfonated with the concentrated sulfuric acid and then, converted to the potassium natural asphalt sulfonate (K-NAS). In order to characterization of the nanocatalyst, used of FT-IR spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and thermogravimetric analysis (TGA) techniques. This new basic heterogeneous nanocatalyst have advantages such as being eco-friendly, huge specific surface area, high reactivity and recyclability.
- Falah, Saeid,Soleiman-Beigi, Mohammad,Kohzadi, Homa
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- Synthesis of high-density aviation fuels with methyl benzaldehyde and cyclohexanone
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A new two-step process was developed for the synthesis of high-density jet fuel range tricyclic alkanes with methyl benzaldehydes and cyclohexanone which can be derived from lignocellulose. In the first step, C14 oxygenates (i.e. 2-(2-methylbenzylidene)cyclohexanone or 2-(4-methylbenzylidene)cyclohexanone) were obtained by the solvent-free aldol condensation of 2-methyl benzaldehyde (or 4-methyl benzaldehyde) and cyclohexanone. Among the investigated catalysts, the EAOAc ionic liquid (a renewable catalyst which was prepared with ethanolamine and acetic acid) exhibited the highest activity and good stability for this reaction. Over it, high carbon yields (~85%) of C14 oxygenates were achieved under mild reaction conditions (353 K, 6 h). In the second step, the C14 oxygenates were selectively converted into 1-methyldodecahydro-1H-fluorene and 3-methyldodecahydro-1H-fluorene by the aqueous phase hydrodeoxygenation (APHDO) over a commercial Pd/C catalyst. According to our measurement, the 1-methyldodecahydro-1H-fluorene and 3-methyldodecahydro-1H-fluorene as obtained have high densities (0.99 g mL-1 and 0.96 g mL-1, respectively, at 298 K). As a potential application, they can be used as additives to improve the volumetric heat values of the current bio-jet fuels.
- Xu, Jilei,Li, Ning,Li, Guangyi,Han, Fengan,Wang, Aiqin,Cong, Yu,Wang, Xiaodong,Zhang, Tao
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supporting information
p. 3753 - 3760
(2018/08/22)
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- Sulfonated PEG-intercalated montmorillonite [(Mt/PEG)-SO3H] as efficient and ecofriendly nanocatalyst for synthesis of α,α′-bis(substituted benzylidene)cycloalkanones
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(Montmorillonite/PEG)-SO3H nanocomposite was successfully prepared for the first time and introduced as a solid acid nanocatalyst. Initially, polyethylene glycol (PEG) polymeric chains were intercalated into interlayer spaces of montmorillonite. The resulting Mt/PEG nanocomposite with good mechanical and thermal stability was chosen as a useful clay mineral/polymer support for further modification with chlorosulfonic acid. Structural characterization of (Mt/PEG)-SO3H was carried out using X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) measurements, Barrett–Joyner–Halenda (BJH) analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier-transform infrared (FT-IR) spectroscopy. The results showed that PEG chains were intercalated into the clay mineral layers and that the Mt/PEG nanocomposite was successfully sulfonated. (Mt/PEG)-SO3H nanocomposite exhibited high specific surface area and good stability up to around 150?°C, showing excellent potential for application as a recyclable nanocatalyst. (Mt/PEG)-SO3H was used as an efficient and ecofriendly solid acid nanocatalyst for preparation of α,α′-bis(substituted benzylidene)cycloalkanones under solvent-free conditions, leading to many interesting findings. The excellent conversion values confirm that the catalyst has strong and sufficient acidic sites, which are responsible for its catalytic performance. The reaction under mild conditions (room temperature) with excellent yield, catalyst recyclability (up to ten times), and simple work-up procedure represent useful advantages of (Mt/PEG)-SO3H for catalysis. Moreover, the reaction could be scaled up to 10 and 15?mmol scales.
- Dalil Heirati, Seyedeh Zahra,Shirini, Farhad,Fallah Shojaei, Abdollah
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p. 6167 - 6186
(2017/10/05)
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- An efficient green approach to aldol and cross-aldol condensations of ketones with aromatic aldehydes catalyzed by nanometasilica disulfuric acid in water
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Aldol and cross-aldol condensations of aromatic aldehydes with various ketones in the presence of nanometasilica disulfuric acid (NMSDSA) as heterogeneous catalyst are presented. The catalyst was prepared according to the developed earlier method using inexpensive and readily available starting materials. The highly active catalyst gave excellent yields of the desired aldol products without self-condensation reaction taking place. Reaction times were short, the procedure and work-up were simple, and no volatile or hazardous organic solvents were involved. The catalyst could be recovered three times with only slight reduction in activity.
- Nakhaei,Morsali,Davoodnia
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p. 1073 - 1078
(2017/06/29)
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- Phase-vanishing method applied to condensation reactions using TiCl4
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The phase-vanishing (PV) method using perfluorohexanes as the phase screen was applied to the aldol condensation using TiCl4 as the Lewis acid. A special test tube was used, in which an interface between the fluorous and organic layers was stirred, and cyclohexanone was treated with two equivalents of benzaldehyde derivatives under PV conditions to afford corresponding 2,6-dibenzylidencyclohexanone in good yields. The formyl-methylenation of ketones with triethylamine using TiCl4 was also demonstrated by the PV method.
- Adachi, Yusuke,Kuniyoshi, Kenji,Matsubara, Hiroshi
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p. 100 - 105
(2017/04/10)
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- Chiral spirodihydroindene skeleton compound and preparation method thereof
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The invention discloses a chiral spirodihydroindene skeleton compound and a preparation method thereof. The chiral spirodihydroindene skeleton compound is represented by formula I or I'. The preparation method of the chiral spirodihydroindene skeleton compound is characterized in that an intramolecular Friedel-Crafts reaction of a compound represented by formula III is carried out in a solvent under the action of a catalyst to prepare the compound represented by formula I, and the catalyst is a Bronsted acid or a Lewis acid. The preparation method has the advantages of no chiral initial raw material or chiral resolution reagent, no chiral resolution steps, simplicity, simplicity in post-treatment, good economic property, environmental protection, high product yield, and realization of high optical purity and high chemical purity of the product. Transition metal catalyzed asymmetric reaction catalysts prepared by adopting the chiral spirodihydroindene skeleton compound have a substantial catalysis effect, the product yield is greater than 99%, and the ee value of the product higher than 99%.
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Paragraph 0116-0119; 0121-0122
(2017/02/28)
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- Synthesis of air-stable mixed bis-carboxylate titanocene complexes and their catalytic behaviors in cross-aldol and Mannich reactions
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Tunable organometallic Lewis acid catalysts were developed by combining salicylic acid (H2-Sal) with benzoic acid (H-Ben), 4-fluorobenzoic acid (H-BenF) and 3-thiophenic acid (H-Th), as coligands for mixed bis-carboxylate titanocene complexes. Three air-stable complexes [Cp2Ti(η1-HSal)(η1-Ben)] (1), [Cp2Ti(η1-HSal)(η1-BenF)] (2) and [Cp2Ti[η1-HSal][(η1-Th)] (3) were prepared in high yields by the reaction of salicylato titanocene chelate with carboxylate ligands. The mixed bis-carboxylate titanocene complexes were fully characterized by physicochemical and spectroscopic methods. Single-crystal X-ray diffraction studies revealed Ti–O(H-Sal) bond distances in 1, 2 and 3 of 1.972(3), 1.9245(18) and 1.912(5)??, respectively, while the bond distances involving the coligands of 1, 2 and 3 are 1.908(3)?? (Ti–OBen), 1.9296(19)?? (Ti–OBenF) and 1.945(5)?? (Ti–OTh), respectively. These bis-carboxylate titanocene complexes showed satisfactory activities and selectivities in Mannich and cross-aldol reactions. Notably, complex 3 bearing the labile thiophene carboxylate ligand gave high yields with a diastereomer ratio (d.r.) as high as 1:99 for the direct Mannich reactions of benzaldehyde, cyclohexanone and aniline. In cross-aldol reaction of benzaldehyde and cyclohexanone, 1 and 2 successfully catalyzed the formation of double-aldol products in up to 99?% yield.
- Wang, Jing,Chen, Xi,Wang, Xiu,Zhang, Wei-Qiang,Sun, Hua-Ming,Zhang, Guo-Fang,Wu, Ya,Gao, Zi-Wei
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p. 731 - 738
(2016/09/13)
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- Design, characterization, and use of N,N-diethyl-N-sulfoethanaminium hydrogen sulfate {[Et3N-SO3H]HSO4} as a novel and highly efficient catalyst for preparation of α,α′-bis(arylidene)cycloalkanones
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Abstract: The aim of this work is to introduce a novel and attractive protic acidic ionic liquid as catalyst for organic synthesis. To achieve this aim, N,N-diethyl-N-sulfoethanaminium hydrogen sulfate {[Et3N-SO3H]HSO4} was prepared by reaction of NEt3 with ClSO3H and then with H2SO4. The novel acidic ionic liquid was identified by Fourier-transform infrared (FT-IR), 1H nuclear magnetic resonance (NMR), 13C NMR, and mass spectroscopies. Its catalytic activity was then examined in the cross-aldol condensation reaction of arylaldehydes with cycloalkanones under solvent-free conditions, obtaining α,α′-bis(arylidene)cycloalkanones in high yield after short reaction time. Graphical Abstract: [Figure not available: see fulltext.]
- Ahmadi, Salimeh,Zare, Abdolkarim,Aali-Hosaini, Mina,Maghsoudi, Maryam,Izadpanah, Shadi,Parhami, Abolfath,Merajoddin, Maria
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p. 6245 - 6253
(2016/07/06)
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- Synthesis, characterization, and crystal structures of α, α'-bis(substituted-benzylidene)cycloalkanone derivatives by nano-TiO2/HOAc
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A new and economical synthesis of α, α'-bis(substituted-benzylidene)cycloalkanones has been achieved by the reaction of cycloalkanones with different aromatic aldehydes using nano-TiO2/acetic acid as a catalyst in ethanol under reflux conditions with excellent yields. Five new products and three new single crystal structures are reported.
- Tabrizian, Elham,Amoozadeh, Ali,Rahmani, Salman,Salehi, Mehdi,Kubicki, Maciej
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p. 531 - 544
(2016/04/26)
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- Chemoselective Claisen-Schmidt bis-substitutional condensation catalyzed by an alkoxy-bridged dinuclear Ti(IV) cluster
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The highly efficient and chemoselective α,α′-bis-substitution of alkanones is important in organic synthesis. Herein, a dimeric titanium cluster, Ti2Cl2(OPri)6·2HOPri (Ti2), is used in the Claisen-Schmidt condensation reaction, for the selectively activation of symmetrical ketones containing α,α′-methylene groups and production of α,α′-bis-substituted alkanones in high efficiency and chemoselectivity. The high efficiency and chemoselectivity can be extended to a variety of typical alkanones and aromatic aldehydes. Both of the oxo-bridged dimeric motif of Ti2 and the ionic Ti-Cl bond are responsible for the high efficiency and chemoselectivity.
- Wu, Yufei,Hou, Jie,Liu, Yuliang,Zhang, Mingfu,Tung, Chen-Ho,Wang, Yifeng
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p. 1511 - 1516
(2016/03/01)
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- Catalyst-free synthesis of (7E)-7-benzylidene-3,3a,4,5,6,7-hexahydro-2,3-diphenyl-2H-indazole derivatives in PEG-400 as a green and reusable solvent
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The reaction of 2,6-bisbenzylidenecyclohexanones and phenylhydrazine in polyethylene glycol (PEG)-400 as a green and reusable solvent under catalyst-free conditions gave hexahydroindazoles as the major product and, in some cases, tetrahydroindazoles were also produced as a minor product. The products were easily separated by simple recrystallisation. The structures of the indazoles were confirmed using FTIR and NMR spectroscopy. Two X-ray structures are reported.
- Amoozadeh, Ali,Tabrizian, Elham,Salehi, Mehdi,Kubicki, Maciej,Rahmani, Salman,Shamsi, Taiebeh,Bitaraf, Mehrnoosh
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p. 535 - 539
(2016/10/05)
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- Hetero-acid titanocenes complex crystal and its synthetic method and in the preparation of α, β - unsaturated carbonyl compounds in the application of the (by machine translation)
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The invention discloses a hetero-acid titanocenes complex crystal and its synthetic method and in the preparation of α, β - unsaturated carbonyl compounds in the application. The structural formula of the complex crystal is In the formula R represents H or F. It is composed of the salicylic acid chelate and benzoic acid or para-benzoic acid prepared. The invention hetero-acid titanocenes complex crystal cheap, non-toxic, stable to air and water, synthetic method the raw materials used are cheap and easy to obtain, synthetic step is simple and, after treatment of the product is easy, high yield, and can realize the gram of the complex preparation. The invention hetero-acid titanocenes complex crystal can be used as a hetero-acid co-catalyst, for catalytic aldehyde ketone condensation reaction for preparing α, β - unsaturated carbonyl compound, the catalytic activity is high, the need for adding solvent, the operation is simple, the atom economy is high. (by machine translation)
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Paragraph 0029; 0039; 0052-0055
(2017/06/19)
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- Bromine and iodine-cucurbit[6]uril complexes: Preparation and applications in synthetic organic chemistry
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Iodine and bromine inclusion compounds were easily prepared by gas diffusion of the halogens using finely powdered CB[6]. A brown powder consisting of I2-CB[6]·4H2O and an orange one of (Br 2)4-CB[6]·10H2O were employed in several different reactions. I2-CB[6] can be used in catalytic reactions giving yields comparable to those reported in the literature. Br 2-CB[6] was effectively applied in electrophilic bromination of benzene and formation of bromohydrin. However, the radical substitution at cyclohexene could not be performed. Overall, based on these results, several applications can be envisioned for these complexes. This journal is the Partner Organisations 2014.
- Reddy,Cavallini,Demets,Silva
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supporting information
p. 2262 - 2264
(2014/06/09)
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- Solvent-free catalytic preparation of 2,6-dibenzylidenecycloalkanones using 2-hydroxyethylammonium acetate ionic liquid as catalyst
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Various 2,6-dibenzylidenecycloalkanones were readily prepared in a condensation reaction catalyzed by 2-hydroxyethylammonium acetate ionic liquid under solvent-free conditions in excellent yields. The major advantages of the present method are high yields, short reaction times, lack of solvent, simplicity of performance, and low cost. Graphical abstract: [Figure not available: see fulltext.]
- Kang, Li Q.,Cai, Yue Q.,Wang, Hao,Li, Li H.
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p. 337 - 340
(2014/03/21)
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- Synthesis, docking, and in vitro studies of some substituted bischalcones on acid and alkaline phosphatases
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A series of bischalcones was synthesized and screened for their effect on acid and alkaline phosphatases. In addition, molecular modeling and docking of these compounds into alkaline phosphatase using iGemdock was performed in order to predict the affinity and orientation of the designed compounds at the active site and was compared with the established inhibitor levamisole. The iGemdock docking fitness resulted in decrease in total energy (ranging from -75.50 to -100.84) for all the synthesized compounds which were less than levamisole (-50.69) revealing higher binding with the enzyme. The compounds were synthesized by Clasien-Schimdt condensation and their effect was observed on the activity of acid and alkaline phosphatases. The results showed that synthesized bischalcones were inhibitory to alkaline phosphatases, whereas an activating effect was observed on the activity of acid phosphatase. The type of inhibition and Ki values of bischalcones on alkaline phosphatase were also determined. Springer Science+Business Media 2013.
- Singh, Mamta,Raghav, Neera
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p. 1781 - 1788
(2014/05/06)
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- Aldol condensations of a variety of different aldehydes and ketones under ultrasonic irradiation using poly(N-vinylimidazole) as a new heterogeneous base catalyst under solvent-free conditions in a liquid-solid system
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An ultrasound-assisted aldol condensation reaction has been developed for a range of ketones with a variety of aromatic aldehydes using poly(N-vinylimidazole) as a solid base catalyst in a liquid-solid system. The catalyst can be recovered by simple filtration and reused at least 10 times without any significant reduction in its activity. The reaction is also amenable to the large scale, making the procedure potentially useful for industrial applications.
- Khaligh, Nader Ghaffari,Mihankhah, Taraneh
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p. 2167 - 2173
(2014/01/06)
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- Sulfuric acid-modified PEG-6000 (PEG-SO3H): An efficient, bio-degradable and reusable catalyst for synthesis of α, α′ bis(arylidene) cycloalkanones under solvent-free conditions
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A green and efficient method for synthesis of α, α′ -bis (arylidene) cycloalkanones, starting from aromatic aldehydes in reaction with ketones using sulfonated polyethylene glycol 6000 (PEG-SO3H) as a stable, reusable and biodegradable catalyst under solvent-free conditions at 80 °C is described. The use of a nontoxic, inexpensive, easily available and recyclable catalyst makes this protocol practical, environmentally friendly and economically attractive.
- Nasseri, Mohammad A.,Salimi, Mehri
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p. 164 - 170
(2013/07/26)
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- Study of in situ generation of carbocationic system from trityl chloride (Ph3CCl) which efficiently catalyzed cross-aldol condensation reaction
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Organocatalyst trityl chloride (Ph3CCl), by in situ formation of trityl carbocation with inherent instability, efficiently promotes the cross-aldol condensation reaction between cycloalkanones and arylaldehydes in solvent-free and homogeneous media to afford α,α′- bis(arylidene)cycloalkanones in high yields. Moreover, an attractive and plausible mechanism based on observations and the literature is proposed for the reaction.
- Zare, Abdolkarim,Merajoddin, Maria,Hasaninejad, Alireza,Moosavi-Zare, Ahmad Reza,Khakyzadeh, Vahid
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p. 380 - 384
(2013/08/25)
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- Cyclization of α,α′-bis(substituted-benzylidene) cyclohexanones and 4-hydroxycoumarin: Synthesis of 11-benzylidene-8,9,10,11- tetrahydro-7-phenyl-6H,7H-chromeno[4,3-b]chromen-6-ones as new pyranochromene derivatives
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A series of new 11-benzylidene-8,9,10,11-tetrahydro-7-phenyl-6H,7H- chromeno[4,3-b]chromen-6-ones has been synthesized through a new Michael addition domino cyclization between α,α′-bis(substituted- benzylidene)cyclohexanones and 4-hydroxycoumarin in acetic acid at reflux conditions. Very good to excellent yields of the products, operational simplicity, and simple workup are attractive features of this synthesis protocol.
- Mahdavinia, Gholam Hossein,Peikarporsan, Somayyeh
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p. 415 - 419
(2013/05/09)
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- A convenient synthesis of α,α'-bis(substituted benzylidene)cycloalkanones Catalyzed by Y(TFA) 3
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Aromatic aldehydes undergo crossed aldol condensation with cyclic ketones in the presence of Y(TFA)3 under solvent-free conditions to afford the corresponding α,α-bis(substituted benzylidene)cycloalkanones in satisfactory yields. Furthermore, the catalyst can be recovered conveniently and reused several times in the reaction with comparable yields. Copyright Taylor & Francis Group, LLC.
- Luo, Genxiang,Wang, Runxia,Liu, Chunsheng
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experimental part
p. 554 - 556
(2012/06/30)
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- Revisit: Eaton's reagent catalyzed synthesis of mono and bis-chalcone derivatives
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Eaton's reagent efficiently catalyzed the Claisen-Schmidt condensation reaction of aryl aldehydes with aromatic and cyclic ketones under solvent free microwave irradiation conditions to afford mono and bis-chalcone derivatives. The present approach offers several advantages such as shorter reaction times, cleaner reactions, good yields, inexpensive reagent and mild reaction conditions.
- Tupare, Shrikrishna A.,Nalage, Santosh V.,Bobe, Sharad R.,Hallale, Shivshankar N.,Bhosale, Sheshanath V.,Vyawahare, Sanjay K.,Dake, Satish A.,Bhosale, Sidhanath V.,Pawar, Rajendra P.
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p. 526 - 529
(2012/10/30)
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- Synthesis and antimicrobial activity of novel tetrabromo-bis(substituted benzyl)cycloalkanones
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A series of novel tetrabromo-bis(substituted benzyl)cycloalkanones have been synthesized through a rapid, simple, and efficient methodology in an excellent isolated yield and characterized via IR, NMR (1H-, 13C-NMR, DEPT 135, DEPT 90) and mass spectrometry. All compounds were assayed for their in vitro antimicrobial activities against eight bacteria and five fungi. They showed stronger antibacterial than antifungal activities. Compounds 4c, 4d and 4i, containing a methoxy or chloro substituent on the para or meta position of the phenyl ring, showed comparable minimum inhibitory concentration (MIC) values to those of the standard antibiotics streptomycin and tetracycline. Among all the tested compounds, 4i exhibited good to moderate antifungal activity against all the tested fungal strains used.
- Motiur Rahman,Alam, Mohammad Sayed,Kadi, Adnan A.
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experimental part
p. 717 - 723
(2012/10/08)
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- Solvent free synthesis of quinoxalines, dipyridophenazines and chalcones under microwave irradiation with sulfated Degussa titania as a novel solid acid catalyst
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Sulfated TiO2-P25 (Degussa titania) has been prepared by sol-gel method using H2SO4 and characterized by FT-IR, XRD, FE-SEM, EDS, HR-TEM, XPS, DRS and BET surface area measurements. Sulfate loading by H2SO4 increases the Lewis acidity of Degussa tiatania. This catalyst gives an excellent yield with less reaction time and is an inexpensive and easily recyclable solid acid catalyst for the synthesis of quinaxalines, dipyridophenazines and chalcones under microwave irradiation.
- Krishnakumar,Swaminathan
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experimental part
p. 16 - 25
(2011/12/14)
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- KF-melamine formaldehyde resin (KF-MFR) as a versatile and efficient heterogeneous reagent for aldol condensation of aldehydes and ketones under microwave irradiation
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KF-Melamine formaldehyde resin (KF-MFR) was demonstrated to be a highly efficient heterogenious catalyst for cross-aldol condensation under microwave irradiation. In this synthesis, various aldehydes and ketones were condensed together in the presence of supported KF on melamine-formaldehyde resin to afford different chalcone derivatives in good to excellent yields. KF-MFR proved to have unique termal and chemical resistance and can be reused for many consecutive runs without remarkable loss in catalytic activity. Copyright
- Rezaie, Ramin,Heidary, Mohammad,Soltani Rad, Mohammad Navid,Behrouz, Somayeh
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experimental part
p. 1221 - 1226
(2012/04/18)
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- Sulfamic acid: An efficient, cost-effective and green catalyst for crossed-aldol condensation of ketones with aromatic aldehydes under solvent-free
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Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of catalytic amount of sulfamic acid (SA) to afford the corresponding α, β-unsaturated aldol products under solvent-free conditions in good to high yields at 45-80 °C.
- Rostami, Amin,Ahmad-Jangi, Firoz
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experimental part
p. 1029 - 1032
(2012/06/01)
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- Amberlyst-15 catalysed microwave assisted cross-aldol condensation between ketones and aldehydes under solvent free condition
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Amberlyst-15 has been applied as an efficient heterogeneous catalyst for the first time for rapid synthesis of α,α′-bis(arylmethylene) cycloalkanones, α,α′-bis(cinnamylidene)cycloalkanones, ′-cinnamylideneacetophenones and chalcones in very good yield by the reaction between various aldehydes and ketones under microwave irradiation. The new process for the cross-aldol condensation reaction works well in absence of any solvent. The yields are high and the process is environmentally benign.
- Pal, Rammohan,Mandal, Tapas K.,Guha, Chayan,Mallik, Asok K.
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experimental part
p. 711 - 717
(2012/03/11)
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- Solvent-free, cross-aldol condensation reaction using silica-supported, phosphorus-containing reagents leading to α,α′-Bis(arylidene) cycloalkanones
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This article describes an efficient, simple, and clean method for the synthesis of α,α′-bis(arylidene, furylidene and cinnamylidene)cycloalkanones under solvent-free conditions. The cross-aldol condensation of cycloalkanones with aldehydes in the presence of silica-supported phosphorus pentoxide (P2O5/SiO 2) or silicaphosphinoxide (silphox, [POCl3-n(SiO 2)n]) as heterogeneous reagents produces the title compounds in good to excellent yields. Copyright Taylor & Francis Group, LLC.
- Hasaninejad, Alireza,Zare, Abdolkarim,Balooty, Laleh,Mehregan, Hadis,Shekouhy, Mohsen
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experimental part
p. 3488 - 3495
(2011/02/22)
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- Poly(ethylene)glycol/AlCl3 as a Green and Reusable System in the Synthesis of α,α′'-bis(substituted-benzylidene) Cycloalkanones
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Aluminum chloride has been found to be a highly efficient catalyst for the aldol condensation of aldehydes and cycloketones in poly(ethylene)glycol 400 at room temperature. The reaction is very fast, clean and environmentally benign for the synthesis of a variety of α,α′'-bis(substituted- benzylidene) cycloalkanones.
- Amoozadeh, Ali,Rahmani, Salman,Nemati, Firouzeh
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experimental part
p. 72 - 74
(2011/06/11)
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- Base-catalysed cyclocondensation of α,α′- bis(arylmethylene)cyclohexanones with thiourea: Formation of E-8-(arylmethylene)-4-aryl-1,2,3,4,5,6,7,8-octahydrobenzo[d]pyrimidine-2-thiones
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Base-catalysed cyclocondensation of α,α′- bis(arylmethylene)cyclohexanones with thiourea has been found to generate E-8-(arylmethylene)-4-aryl-1,2,3,4,5,6,7,8-octahydrobenzo[d]pyrimidine-2- thiones in high yield, the structures of which have been established from their spectral data. However, corresponding cyclopentanones were found to be unreactive under similar reaction condition.
- Pal, Rammohan,Mandai, Tapas K.,Mallik, Asok K.
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body text
p. 402 - 405
(2010/06/16)
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- An efficient and practical procedure for synthesis of α, α′-bis(substituted benzylidene)cycloalkanones catalyzed by solid base SiO2-OK
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The condensation of cycloalkanones with aromatic aldehydes catalyzed by solid base SiO2-OK in refluxing EtOH, result in the formation of the corresponding α,α′-bis(substituted benzylidene)cycloalkanones in good to excellent yields.
- Jin, Tong-Shou,Zhao, Ying,Liu, Li-Bin,Li, Tong-Shuang
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p. 1965 - 1967
(2007/10/03)
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- Study of substituent effects in substituted dibenzal acetones
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The present work involves a detailed study of the ultra-violet absorption spectra of various substituted dibenzylidene ketones derived from acetone, ethyl methyl ketone, diethyl ketone, cyclopentanone and cyclohexanone by condensing with several meta- and para-substituted benzaldehydes in n-hexane and in ethanol to ascertain the transition dominant in these solvents. These ketones exist as equilibrium mixtures of s-cis, cis and s-cis, trans conformations. The ultraviolet absorption spectra of the ketones exhibit two bands due to π* ← π transition around 250 and 320 nm. The 320 nm band is prominent in all the cases. There is no indication of π* ← n transition in any of the spectra. The 320 nm band is structureless in all the cases except those shown by the dibenzylidene ketones derived from cyclopentanone in hexane. Therefore it can be inferred that the dibenzylide ketones derived from all the ketones except those derived from cyclopentanone are non-planar.
- Ananthakrishna Nadar,Renuga
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p. 1219 - 1222
(2008/09/21)
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- Aldol condensations catalyzed by PEG400 and anhydrous K2CO 3 without solvent
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Aldol condensations of aromatic aldehydes with ketones under solvent-free conditions to synthesize α,β-unsaturated ketones in good to excellent yields using PEG400 and powdered anhydrous K2CO3 as catalysts at 90°C and 120°C are described. Copyright Taylor & Francis, Inc.
- Cao, Yu-Qing,Dai, Zhi,Zhang, Rui,Chen, Bao-Hua
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p. 1045 - 1049
(2007/10/03)
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- InCl3·4H2O/TMSCl-catalysed aldol reaction of aromatic aldehydes with cycloalkanones in ionic liquid medium
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An efficient and practical preparation of α,α′- bis(substituted benzylidene) cycloalkanone derivatives from cycloalkanones and aromatic aldehydes promoted by InCl3-4H2O/TMSCl in ionic liquid ([bmim][BF4]) is described.
- Hu, Xueyuan,Fan, Xuesen,Zhang, Xinying,Wang, Jianji
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p. 684 - 686
(2007/10/03)
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- Synthesis of α,α′-bis(substitutedbenzylidene) cycloalkanones by a grinding method
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KF-Al2O3 catalyses the crossed aldol condensation of various aromatic aldehydes with cycloalkanones, giving corresponding α,α′-bis(substitutedbenzylidene)cycloalkanones under solvent free conditions by a grinding method at room temperature.
- Wang, Shu-Xiang,Li, Ji-Tai,Geng, Li-Jun
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p. 370 - 371
(2007/10/03)
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- A facile route to synthesize α,α'-bis(substituted-benzylidene) cycloalkanones promoted by SmI3
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Promoted by SmI3 cycloalkanone trimethylsilyl enol ethers were reacted with aldehydes to give α,α-bis(substituted-benzylidene) cycloalkanones.
- Bao, Weiliang,Zhang, Yongmin,Ying, Taokai
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p. 503 - 507
(2007/10/03)
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- Synthesis and cytotoxic evaluation of some cyclic arylidene ketones and related oximes, oxime esters, and analogs
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A number of arylidene derivatives of alicyclic ketones and some corresponding oximes, oxime esters, and related compounds were prepared as candidate cytotoxic agents. All of the compounds were evaluated against murine L1210 lymphoid leukemia cells. In general, cytotoxicity was greatest with the α,β-unsaturated ketones and diminished with the oximes, and the oxime esters had little or no activity in this screen. When the same compounds were examined in both the in vitro L1210 and P388 leukemia screens, in the majority of cases the L1210 cells were more sensitive to these derivatives. Over half of the compounds prepared were evaluated against approximately 55 human tumors in vitro and showed selective toxicity toward one or more groups of neoplastic diseases, particularly leukemia. Some correlations between structure and bioactivity were discerned. The cytotoxicity screening and stability studies of representative compounds suggested that the ketones, oximes, and oxime esters were stable under the conditions of bioevaluation. X-ray crystallography of four representative compounds revealed structural features associated with cytotoxicity which may be considered in the design of future candidate cytotoxins.
- Dimmock,Sidhu,Chen,Li,Quail,Allen,Kao
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p. 852 - 858
(2007/10/02)
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