- The first molecular dumbbell consisting of an endohedral Sc3N@C80 and an empty C60-fullerene building block
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An unprecedented hybrid dumbbell consisting of a metallofullerene and an empty fullerene was afforded via simple click reaction of suitable precursor derivatives of Sc3N@C80 and a C60 hexakisadduct.
- Wei, Tao,Pérez-Ojeda, M. Eugenia,Hirsch, Andreas
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Read Online
- Kinetics and mechanism for oxime formation from 4-dimethylaminobenzaldehyde and 4-trimethylammoniobenzaldehyde iodide
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The following lines of evidence establish that oxime formation from 4-dimethylaminobenzaldehyde and 4-trimethylammoniobenzaldehyde iodide occurs with a simple two-step mechanism. The pH-rate profile for the reaction of 4-trimethylammoniobenzaldehyde iodid
- Malpica,Calzadilla,Cordova,Torres,Saulny
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Read Online
- A catalytic regioselective procedure for the synthesis of aryl oximes in the presence of palladium nanoparticles
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The synthesis of aryl oximes from aryl aldehyde derivatives was carried out using hydroxylamine hydrochloride and aluminum oxy hydroxide-supported palladium (Pd/AlO(OH) nanoparticles. The procedure is revealed via the regioselective synthesis of oxime der
- Demir, Emine,Goksu, Haydar,Orhan, Ersin
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- Effect of the Steric Hindrance and Branched Substituents on Visible Phenylamine Oxime Ester Photoinitiators: Photopolymerization Kinetics Investigation through Photo-DSC Experiments
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In this work, free radical photopolymerization (FRP) kinetics for series of different phenylamine oxime ester structures (DMA–P, DEA–P, DMA–M, TP–2P, TP–2M and TP–3M) was investigated. Steric hindrance and branched substituents were prepared to realize th
- Chen, Ching-Chin,Chen, Yung-Chung,Graff, Bernadette,Hammoud, Fatima,Hijazi, Akram,Huang, Tung-Liang,Lalevée, Jacques,Lee, Zhong-Han
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- Poly(N-vinylimidazole): A biocompatible and biodegradable functional polymer, metal-free, and highly recyclable heterogeneous catalyst for the mechanochemical synthesis of oximes
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The catalytic activity of poly(N-vinylimidazole), a biocompatible and biodegradable synthetic functional polymer, was investigated for the synthesis of oximes as an efficient, halogen-free, and reusable heterogeneous catalyst. The corresponding oximes were afforded in high to excellent yields at room temperature and in short times using the planetary ball mill technique. Some merits, such as the short reaction times and good yields for poorly active carbonyl compounds, and avoiding toxic, expensive, metal-containing catalysts, and hazardous and flammable solvents, can be mentioned for the current catalytic synthesis of the oximes. Furthermore, the heterogeneous organocatalyst could be easily separated after the reaction, and the regenerated catalyst was reused several times with no significant loss of its catalytic activity.
- Fahim, Hoda,Ghaffari Khaligh, Nader,Gorjian, Hayedeh
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p. 2007 - 2012
(2022/01/08)
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- Synthesis and biological evaluation of novel isoxazole derivatives from acridone
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The present study was carried out in an?attempt to synthesize a new class of potential antibacterial agents. In this context, novel isoxazoles were synthesized and evaluated for their potential antibacterial behavior against four pathogenic bacterial strains. The synthesized compounds exhibited moderate-to-good antibacterial activity against these strains. The highest antibacterial activity was observed against the Escherichia coli strains, particularly for compounds 4a and 4e with phenyl and para-nitrophenyl groups on the isoxazole–acridone skeleton;?they showed promising minimum inhibitory concentration values of 16.88 and 19.01 μg/ml, respectively, compared with the standard drug chloramphenicol (22.41 μg/ml). The synthesized compounds were subjected to in silico docking studies to understand the mode of their interactions with the DNA topoisomerase complex (PDB ID: 3FV5) of E. coli. The molecular docking results showed that compounds 4a–l occupy the active site of DNA topoisomerase (PDB ID: 3FV5), stabilized via hydrogen bonding and hydrophobic interactions, which may be the reason behind their interesting in vitro antibacterial activity.
- Aarjane, Mohammed,Slassi, Siham,Tazi, Bouchra,Amine, Amina
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- Synthesis and SAR study of simple aryl oximes and nitrofuranyl derivatives with potent activity against Mycobacterium tuberculosis
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Background: Oximes and nitrofuranyl derivatives are particularly important compounds in medicinal chemistry. Thus, many researchers have been reported to possess antibacterial, antiparasitic, insecticidal and fungicidal activities. Methods: In this work, we report the synthesis and the biological activity against Mycobacterium tuberculosis H37RV of a series of fifty aryl oximes, ArCH=N-OH, I, and eight nitrofuranyl compounds, 2-nitrofuranyl-X, II. Results: Among the oximes, I: Ar = 2-OH-4-OH, 42, and I: Ar = 5-nitrofuranyl, 46, possessed the best activity at 3.74 and 32.0 μM, respectively. Also, 46, the nitrofuran compounds, II; X = MeO, 55, and II: X = NHCH2Ph, 58, (14.6 and 12.6 μM, respectively), exhibited excellent biological activities and were non-cytotoxic. Conclusion: The compound 55 showed a selectivity index of 9.85. Further antibacterial tests were performed with compound 55 which was inactive against Enterococcus faecalis, Klebisiella pneumonae, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhymurium and Shigel-la flexneri. This study adds important information to the rational design of new lead anti-TB drugs. Structure-activity Relationship (SAR) is reported.
- Calixto, Stephane Lima,Carvalho, Guilherme da Silva Louren?o,Coimbra, Elaine Soares,Granato, Juliana da Trindade,Louren?o, Maria Cristina da Silva,Wardell, James,da Costa, Cristiane Fran?a,de Souza, Marcus Vinicius Nora
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- SO2F2-Mediated one-pot cascade process for transformation of aldehydes (RCHO) to cyanamides (RNHCN)
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A simple, mild and practical cascade process for the direct conversion of aldehydes to cyanamides was developed featuring a wide substrate scope and great functional group tolerability. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable cyanamides in a pot, atom, and step-economical manner with a green nitrogen source. This protocol will serve as a robust tool for the installation of the cyanamide moiety in various complicated molecules.
- Ding, Chengrong,Ge, Shuting,Wei, Junjie,Zhang, Guofu,Zhao, Yiyong
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p. 17288 - 17292
(2020/05/18)
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- Design, synthesis of novel 4,5-dihydroisoxazole-containing benzamide derivatives as highly potent FtsZ inhibitors capable of killing a variety of MDR Staphylococcus aureus
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Antibiotic resistance among clinically significant bacterial pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. As a part of continuing effort to develop antibacterial agents, we rationally designed and synthesized two series of 4,5-dihydroisoxazol-5-yl and 4,5-dihydroisoxazol-3-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compound A16 possessing the 4,5-dihydroisoxazol-5-yl group showed outstanding antibacterial activity (MIC, ≤0.125–0.5 μg/mL) against various testing strains, including methicillin-resistant, penicillin-resistant and clinical isolated S. aureus strains. Besides, further mouse infection model revealed that A16 could be effective in vivo and non-toxic to Hela cells. Finally, a detailed discussion of structure-activity relationships was conducted, referring to the docking results. It is worth noting that substituting a 4,5-dihydroisoxazole ring for the isoxazole ring not only broadened the antibacterial spectrum but also resulted in a significant increase in antibacterial activity against S. aureus strains. Taken together, these results suggest a promising chemotype for the development of new FtsZ-targeting bactericidal agents.
- Song, Di,Bi, Fangchao,Zhang, Nan,Qin, Yinhui,Liu, Xingbang,Teng, Yuetai,Ma, Shutao
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supporting information
(2020/09/11)
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- Annulation of Oxime-Ether Tethered Donor–Acceptor Cyclopropanes
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Novel oxime-ether tethered cyclopropanes, when exposed to Yb(OTf)3 and heat, annulate to generate hydropyrrolo-oxazines products that can be taken to their respective pyrrolidines via hydrogenative N?O bond cleavage. The hydropyrrolo-oxazines are generated in a diastereoselective manner isolating the cis or trans product based on the temperature of the reaction. 20 examples of selective cis and trans hydropyrrolo-oxazines were generated in high yields by temperature control.
- Irwin, Lauren C.,Allen, Meredith A.,Vriesen, Matthew R.,Kerr, Michael A.
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supporting information
p. 171 - 175
(2019/12/24)
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- Synthesis and in vitro evaluation of neutral aryloximes as reactivators of Electrophorus eel acetylcholinesterase inhibited by NEMP, a VX surrogate
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Casualties caused by nerve agents, potent acetylcholinesterase inhibitors, have attracted attention from media recently. Poisoning with these chemicals may be fatal if not correctly addressed. Therefore, research on novel antidotes is clearly warranted. Pyridinium oximes are the only clinically available compounds, but poor penetration into the blood-brain barrier hampers efficient enzyme reactivation at the central nervous system. In searching for structural factors that may be explored in SAR studies, we synthesized and evaluated neutral aryloximes as reactivators for acetylcholinesterase inhibited by NEMP, a VX surrogate. Although few tested compounds reached comparable reactivation results with clinical standards, they may be considered as leads for further optimization.
- Cavalcante, Samir F. de A.,Kitagawa, Daniel A.S.,Rodrigues, Rafael B.,Bernardo, Leandro B.,da Silva, Thiago N.,dos Santos, Wellington V.,Correa, Ana Beatriz de A.,de Almeida, Joyce S.F.D.,Fran?a, Tanos C.C.,Ku?a, Kamil,Simas, Alessandro B.C.
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- Exploring isoxazoles and pyrrolidinones decorated with the 4,6-dimethoxy-1,3,5-triazine unit as human farnesyltransferase inhibitors
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Unprecedented triazinyl-isoxazoles were afforded via an effective cycloaddition reaction between nitrile oxides and the scarcely described 2-ethynyl-4,6-dimethoxy-1,3,5-triazine as dipolarophile. The biological evaluation of the newly synthesized compounds showed that the inhibition of human farnesyltransferase by zinc complexation could be improved with triazine-isoxazole moieties. The replacement of the isoxazole unit by a pyrrolidin-2-one was detrimental to the inhibitory activity while the pyrrolidin-2-thione derivatives conserved the biological potential. The potential of selected compounds to disrupt protein farnesylation in Chinese hamster ovary (CHO) cells transfected with pEGFP-CAAX was also evaluated.
- Lucescu, Liliana,Ghinet, Alina,Shova, Sergiu,Magnez, Romain,Thuru, Xavier,Farce, Amaury,Rigo, Beno?t,Belei, Dalila,Dubois, Jo?lle,B?cu, Elena
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- Fe3O4@SiO2@Im[Cl]Mn(III)-complex as a highly efficient magnetically recoverable nanocatalyst for selective oxidation of alcohol to imine and oxime
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An efficient and environmentally friendly oxidation process for the one-pot preparation of oxime, imine and carbonyl compounds through alcohol oxidation in the presence of H2O2 and/or O2 have been developed by a melamine-Mn(III) Schiff base complex supported on Fe3O4@SiO2–Cl nanoparticles, named as Fe3O4@SiO2@Im[Cl]Mn(III)-complex nanocomposite, at room temperature. Direct oxidation of alcohol to carboxylic acid was performed using the catalyst in the presence of molecular O2 at room temperature in a different approach. The oxidation products were obtained with excellent yields and high TOFs. The properties of the catalyst were characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis (C, H, N), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), inductive coupled plasma (ICP), cyclic voltammetry (CV), nuclear magnetic resonance (1H & 13C NMR), vibration sample magnetometer (VSM), Brunauer– Emmett–Teller (BET) and differential pulse voltammetry (DPV) analyses. The mechanism of the oxidation processes was investigated for the both H2O2 and O2 oxidants. The role of the imidazolium moiety in the catalyst as a secondary functionality was investigated. Chemoselectivity behavior of the catalyst was studied by some combinations. The catalyst could be recycled from the reaction mixture by a simple external magnet and reused for several times without any considerable reactivity loss.
- Kazemnejadi, Milad,Alavi, Seyyedeh Ameneh,Rezazadeh, Zinat,Nasseri, Mohammad Ali,Allahresani, Ali,Esmaeilpour, Mohsen
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p. 230 - 249
(2019/03/28)
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- 7-Oxa-4-thia-1-aza-bicyclo[3.2.1]octane 4,4-Dioxides: Mechanochemical Synthesis by Tandem Michael Addition–1,3-Dipolar Cycloaddition of Aldoximes and Evaluation of Antibacterial Activities
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A solvent-free, green, and efficient mechanochemical method for the synthesis of a series of bridged bicyclo aza-sulfone derivatives, namely 7-oxa-4-thia-1-aza-bicyclo[3.2.1]octane 4,4-dioxides through tandem Michael addition–1,3-dipolar cycloaddition of aldoximes was developed. Mechanochemical grinding/milling facilitates quick formation of aldoximes from corresponding aldehydes and hydroxylamine, which upon reaction with divinyl sulfone in a mixer mill affords 7-oxa-4-thia-1-aza-bicyclo[3.2.1]octane 4,4-dioxide derivatives in good overall yields. The newly synthesized bicyclo aza-sulfone derivatives 4 were screened for antibacterial activities. Mostly bicyclo aza-sulfones derived from electron-rich aromatic aldehydes inhibit the growth of Mycobacterium smegmatis (mc2155) and those from aliphatic aldehydes the growth of Escherichia coli (DH5α) in moderate to good effect. However, butyraldehyde-derived compound 4r was very effective against both M. smegmatis and E. coli. The key advantages of this mechanochemical method are catalyst- and solvent-free conditions, shorter reaction time, and formation of a new series of 7-oxa-4-thia-1-aza-bicyclo[3.2.1]octane 4,4-dioxide derivatives, which are good antibacterial agents against M. smegmatis and E. coli.
- Bhutia, Zigmee T.,Das, Avijit,Biswas, Malabika,Chatterjee, Amrita,Banerjee, Mainak
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p. 506 - 514
(2018/02/09)
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- Copper-catalysed synthesis of 3,5-disubstituted isoxazoles enabled by pyridinyl benzimidazol (PBI) as a bidentate N-chelating ligand under mild conditions
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In this paper, we introduced pyridinyl benzimidazol (PBI) as an easy-to-handle and bidentate N-chelating ligand that promote clean synthesis of 3,5-disubstituted isoxazoles in the presence of copper acetate as catalyst. This catalytic approach initiates with the hydroxyamination of aldehydes followed by chlorination and then generation of nitrile oxide which subsequently undergoes click-type [3?+?2]-dipolar cycloaddition with alkynes to give isoxazoles. This method provides an alternative green process to construct isoxazole derivatives.
- Khalifeh, Reza,Shahriarpour, Fatemeh,Sharghi, Hashem,Aberi, Mahdi
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p. 813 - 821
(2018/03/01)
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- Design, synthesis and structure-based optimization of novel isoxazole-containing benzamide derivatives as FtsZ modulators
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Antibiotic resistance among clinically significant bacterial pathogens is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. Utilizing computational docking method and structure-based optimization strategy, we rationally designed and synthesized two series of isoxazol-3-yl- and isoxazol-5-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compounds B14 and B16 that possessed the isoxazol-5-yl group showed strong antibacterial activity against various testing strains, including methicillin-resistant Staphylococcus aureus and penicillin-resistant S. aureus. Further molecular biological studies and docking analyses proved that the compound functioned as an effective inhibitor to alter the dynamics of FtsZ self-polymerization via a stimulatory mechanism, which finally terminated the cell division and caused cell death. Taken together, these results could suggest a promising chemotype for development of new FtsZ-targeting bactericidal agent.
- Bi, Fangchao,Song, Di,Zhang, Nan,Liu, Zhiyang,Gu, Xinjie,Hu, Chaoyu,Cai, Xiaokang,Venter, Henrietta,Ma, Shutao
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- Copper (II)-catalysed direct conversion of aldehydes into nitriles in acetonitrile
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A mild one-pot method for the direct conversion of aryl, heteroaryl and alkyl aldehydes into nitriles was achieved by forming the corresponding oximes in situ with NH2OH and allowing them to react with CuO and acetonitrile. Yields of the 13 nitriles prepared were moderate to very good (62–91%).
- Ma, Xiaoyun,Ao, Jun,Chen, Zhengjian,Liu, Yi
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p. 465 - 468
(2017/08/18)
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- One-pot conversion of aldehydes to nitriles mediated by TiCl4
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A simple and convenient one-pot synthesis of nitriles from the corresponding aliphatic and aromatic aldehydes has been developed. The titanium tetrachloride assisted reaction was conducted in pyridine under mild conditions using various types of aldehyde precursors and gave the corresponding nitriles in excellent yields. The application of the adopted protocol to isolated aldoxime intermediates provided the corresponding nitriles with yields comparable to those using the one-pot procedure.
- Leggio, Antonella,Belsito, Emilia Lucia,Gallo, Sonia,Liguori, Angelo
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p. 1512 - 1514
(2017/03/23)
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- Synthesis and bioactivity of novel isoxazole chalcone derivatives on tyrosinase and melanin synthesis in murine B16 cells for the treatment of vitiligo
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A new series of chalcone derivatives 1–18, bearing isoxazole moieties were designed and synthesized, and biologically evaluated for their activity on mushroom tyrosinase and melanin synthesis in murine B16 cells. The result indicated that most of prepared compounds 1–18 showed potent activating effect on tyrosinase, especially for 1–2, 4, 6–7, 9 and 15. Among them, compounds 2, 4 and 9 demonstrated the best activity with EC50?=?1.3, 2.5 and 3.0?μmol·L?1respectively, much better than the positive control 8-methoxypsoralan (8-MOP, EC50?=?14.8?μmol·L?1); In B16 cells, all the tested compounds exhibited a stronger activity on melanogenesis than 8-MOP (with the value of 115%). It was interesting that derivatives substituted with halogen (1, 2, 4, 5, 7, 9) were generally more potent. Compounds 2 (463%) and 18 (438%) with 3 and 4-fold potency compared with 8-MOP respectively, were recognized as the most promising candidate hits for further pharmacological study of anti-vitiligo.
- Niu, Chao,Yin, Li,Nie, Li Fei,Dou, Jun,Zhao, Jiang Yu,Li, Gen,Aisa, Haji Akber
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p. 5440 - 5448
(2016/10/24)
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- An efficient comparison of methods involving conventional, grinding and ultrasound conditions for the synthesis of fulleroisoxazolines
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In this research, an efficient comparison between conventional, grinding and sonication methods for the synthesis of fulleroisoxazolines was investigated. Compared to the conventional methods, ultrasound procedure showed several advantages including mild reaction conditions, high yields, short reaction times and environmental friendliness.
- Safaei-Ghomi, Javad,Masoomi, Reihaneh
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p. 212 - 218
(2015/02/19)
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- Efficient synthesis of bis-isoxazole ethers via 1,3-dipolar cycloaddition catalysed by Zn/Zn2+ and their antifungal activities
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An efficient method was developed for synthesising isoxazoles. A series of novel bis-isoxazole ether compounds VI, VII and VIII were synthesised starting from different substituted aldehydes (I) via a 1,3-dispolar cycloaddition using Zn/Zn2+ as a catalyst; these were characterised by FT-IR, HRMS, 1H NMR and 13C NMR spectroscopy. In addition, the antimicrobial properties of the synthesised products were investigated. The synthesised compounds exhibited significant antifungal activities in comparison with the standard drugs, fluconazole and itraconazole. It was found that Candida albicans was sensitive to 2-substituted phenyl bis-isoxazole ethers bearing pyridyl.
- Zhang, Da-Wei,Lin, Feng,Li, Bo-Chao,Liu, Hong-Wei,Zhao, Tian-Qi,Zhang, Yu-Min,Gu, Qiang
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p. 1500 - 1511
(2015/09/15)
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- 3-methyl-4-oxa-5-azahomoadamantane as an organocatalyst for the aerobic oxidation of primary amines to oximes in water
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A simple and efficient catalytic system for the aerobic oxidation of primary amines into corresponding oximes has been developed, with 3-methyl-4-oxa-5-azahomoadamantane as catalyst, acetaldoxime as co-catalyst and water as solvent. This process, which uses oxygen (O2) as an economic and green oxidant and water as a green solvent, tolerates a wide range of substrates, affording the target oximes in moderate to excellent yields. It was found that high selectivity was achieved when 3-methyl-4-oxa-5-azahomoadamantane was used, and E-type oximes were the only detected products. A possible mechanism for this catalytic process is proposed.
- Yu, Jiatao,Jin, Yong,Lu, Ming
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supporting information
p. 1175 - 1180
(2015/04/22)
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- Copper(ii)-promoted direct conversion of methylarenes into aromatic oximes
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A simple and efficient catalytic system for direct conversion of methylarenes into aromatic oximes has been developed, with Cu(OAc)2 as catalyst, NHPI (N-Hydroxyphthalimide) as additive, TBN (tert-butyl nitrite) as both the nitrogen source and the oxidant. This process proceeds under mild conditions, tolerates a wide range of substrates, affording the targeted aromatic oximes in 63-86% yields.
- Yu, Jiatao,Lu, Ming
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supporting information
p. 7397 - 7401
(2015/07/15)
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- Copper(II)-promoted direct conversion of methylarenes into aromatic oximes
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A simple and efficient catalytic system for direct conversion of methylarenes into aromatic oximes has been developed, with Cu(OAc)2 as catalyst, NHPI (N-Hydroxyphthalimide) as additive, TBN (tert-butyl nitrite) as both the nitrogen source and the oxidant. This process proceeds under mild conditions, tolerates a wide range of substrates, affording the targeted aromatic oximes in 63-86% yields.
- Yu, Jiatao,Lu, Ming
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supporting information
p. 7397 - 7401
(2015/11/27)
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- Microwave-assisted synthesis of fulleropyrazolines/fulleroisoxazolines mediated by (diacetoxyiodo)benzene: A rapid and green procedure
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Microwave as a green, rapid and effective procedure has been applied to the synthesis of fulleropyrazolines/fulleroisoxazolines. The reaction mixtures containing substituted phenylhydrazones/oximes, C60 and PhI(OAc) 2 allowed to achieve products at room temperature in a good yield and short time without any side product.
- Safaei-Ghomi, Javad,Masoomi, Reihaneh
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p. 2954 - 2960
(2014/01/06)
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- A novel and efficient catalytic system including TEMPO/acetaldoxime/InCl3 for aerobic oxidation of primary amines to oximes
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A simple and efficient catalytic system including TEMPO/acetaldoxime/InCl3 for aerobic oxidation of primary amines to corresponding oximes by using toluene as the solvent is described. This practical method can use O2 as the economic and green oxidant, tolerate a wide range of substrates, which can afford the target oximes in moderate to excellent yields.
- Yu, Jiatao,Cao, Xiaohua,Lu, Ming
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supporting information
p. 5751 - 5755
(2015/02/02)
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- Metal-Free: A novel and efficient aerobic oxidation of primary amines to oximes using N, N', N''-trihydroxyisocyanuric acid and acetaldoxime as catalysts in water
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A general, efficient, and metal-free method for aerobic oxidation of aromatic primary amines to the corresponding oximes catalyzed by N,N',N''-trihydroxyisocyanuric acid and acetaldoxime with water as solvent is described. This practical method can use air as economic and green oxidant, water as green solvent, and tolerates a wide range of substrates, which can afford the target oximes in moderate to good yields. Georg Thieme Verlag Stuttgart. New York.
- Yu, Jiatao,Lu, Ming
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p. 1873 - 1878
(2014/08/18)
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- Green and highly selective protocol for the synthesis of oximes
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A green and efficient protocol has been developed for the synthesis of either exclusively a monoxime or exclusively a dioxime from a host of 1,2-dicarbonyl compounds on silica.
- Ghosh, Pranab,Subba, Raju
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p. 529 - 532
(2013/11/06)
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- Efficient conversion of aldehydes and ketones into oximes using a nanostructured pyrophosphate catalyst in a solvent-free process
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A nanostructured pyrophosphate (Na2CaP2O7) was synthesized by controlling the speed of its calcination, and then characterized by several methods including TGA, X-ray diffraction, FTIR, SEM, TEM and the determination of the surface area by the BET method. However, several aldehydes and ketones were efficiently and rapidly converted into the corresponding oximes by treatment with hydroxylamine hydrochloride in a solvent-free process under microwave irradiation using this nanostructured pyrophosphate as catalyst. The yields of the products were very high and the time required for their preparation was very short compared to conventional heating experiments and the catalyst was efficiently re-used.
- Elmakssoudi, Abdelhakim,Abdelouahdi, Karima,Zahouily, Mohamed,Clark, James,Solhy, Abderrahim
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- The effect of neutral oximes on the reactivation of human acetylcholinesterase inhibited with paraoxon
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Important defense agents against chemical warfare weapons, which are reactivators of human acetylcholinesterase (huAChE) inhibited by neurotoxic organophosphorus compounds (OP), need a reasonable permeation of the hematoencephalic barrier (HB). In this wo
- Ribeiro, Tatiana S.,Prates, Arthur,Alves, Se?rgio R.,Oliveira-Silva, Jefferson J.,Riehl, Carlos A. S.,Figueroa-Villar, J. Daniel
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experimental part
p. 1216 - 1225
(2012/10/18)
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- Solvent free, microwave assisted conversion of aldehydes into nitriles and oximes in the presence of NH2OH · HCl and TiO2
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Aromatic aldehydes bearing electron-donating groups are easily converted into their respective nitriles using NH2OH · HCl and TiO 2 under microwave irradiation, while those bearing an electron-withdrawing group give the corresponding oximes.
- Hoelz, Lucas Villas-Boas,Goncalves, Biank Tomaz,Barros, Jose Celestino,Silva, Joaquim Fernando Mendes Da
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experimental part
p. 94 - 99
(2010/05/18)
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- Metal-free artificial nucleases based on simple oxime and hydroxylamine scaffolds
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Hydrolysis of DNA is of increasing importance in biotechnology and medicine. In this Letter, we present the DNA-cleavage potential of metal-free hydroxylamines and oximes as new members of nucleic acid cleavage agents.
- Fernandes, Luciano,Fischer, Franciele L.,Ribeiro, Carolina W.,Silveira, Gustavo P.,Sa, Marcus M.,Nome, Faruk,Terenzi, Hernan
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supporting information; experimental part
p. 4499 - 4502
(2009/04/08)
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- Biologically active hydroxymoyl chlorides as antifungal agents
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Several oximes and oxime ethers have been developed as antimicrobial agents. A series of chlorooximes (hydroximoyl chlorides) have been synthesized and tested for antifungal activity under in-vitro conditions against Candida albicans, Candida parapsilosis, Candida glabrata, Candida krusei, Aspergillus fumigatus, Aspergilhis flaviis and Aspergillus niger. The derived antifungal activity has been compared with the corresponding oximes. The results show that most of the chlorooximes exhibit potent antifungal activity with anti-isomers showing better activity. It is observed that most of the chlorooximes show interesting antifungal activity (MICs ≤ 32 μg/mL) compared to oximes. Compound 3q (2,3-dimethoxy phenyl hydroxymoyl chloride) is the most active compound. This compound is active against all the Candida species (MIC 0.5 μg/mL) as well as filamentous fungi with MIC range of 2-4 μg/mL. This series of compounds are fungicidal in nature as evident from the MFC results.
- Ismail, Tabasum,Shafi, Syed,Singh, Parvinder Pal,Qazi, Naveed Ahmed,Sawant, Sanghapal D.,Ali, Intzar,Khan, Inshad Ali,Kumar,Qazi, Ghulam Nabi,Alam, M. Sarwar
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p. 740 - 747
(2008/12/20)
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- A simple synthesis of oximes
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The conversion of alicyclic and aliphatic carbonyl compounds as well as aromatic aldehydes into the corresponding oximes (up to quantitative yields) was achieved by simply grinding these reactants, hydroxylamine hydrochloride and sodium hydroxide without solvent. However, this procedure was unsuccessful in the case of aromatic ketones. In this case it was necessary to add silica gel as a catalyst. Springer-Verlag 2006.
- Damljanovic, Ivan,Vukicevic, Mirjana,Vukicevic, Rastko D.
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p. 301 - 305
(2007/10/03)
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- Substituent effects on 15N and 13C NMR chemical shifts of 3-phenylisoxazoles: A theoretical and spectroscopic study
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The synthesis and assignment of 15N and 13C NMR signals of the isoxazole ring in a series of parasubstituted 3-phenyl derivatives are reported. DFT calculations of 15N and 13C chemical shifts are presented and c
- Schofield, Mark H.,Sorel, Marie-Adele,Manalansan, Ryan J.,Richardson, David P.,Markgraf, J. Hodge
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p. 851 - 855
(2007/10/03)
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- Catalytic effect of wet molecular sieve 3A in dry media on syntheses of oximes and 1,3-dioximes
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A simple, efficient and eco-friendly method has been developed for the condensation of hydroxylamine hydrochloride with aldehydes, ketones and 1,3-diketones in the presence of powdered molecular sieves (3A) as catalyst. Aldoximes, ketoximes and 1,3-dioximes were obtained in excellent yields.
- Bigdeli, Mohammadali,Rahmati, Abbas
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p. 605 - 607
(2007/10/03)
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- Solventless rapid synthesis of oxime, semicarbazone, and phenylhydrazone derivatives from carbonyl compounds under microwave conditions
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A rapid and efficient method for the synthesis of oximes, semicarbazones, and phenylhydrazones has been reported under solventless conditions using microwave irradiation. CSIRO 2005.
- Kamakshi,Reddy, Boreddy S. R.
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p. 603 - 606
(2007/10/03)
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- Isoxazole-containing thiourea inhibitors useful for treatment of varicella zoster virus
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This Invention provides a compound of the Formula: wherein X is R1, R2, R3 and R4 are described in the specification and a pharmaceutical composition comprising the compound used for inhibiting replication of a
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- Reactivity of p-substituted benzaldoximes in the cleavage of p-nitrophenyl acetate: Kinetics and mechanism
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Eleven p-substituted benzaldoximes (p-XC6H4CH=NOH, where X = H, CH3, CF3, F, Cl, Br, OCH3, N(CH3)2, COOCH3, CN, NO2) have been synthesized and their dissociation constants determined in 10% (v/v) aqueous dioxane at 35°C. Under the same conditions, the pseudofirst order rate constants kobs of their reactions with p-nitrophenyl acetate (PNPA) were measured at pH values from 7.8 to 10.8 and at concentrations c oxime ranging from 0 to 4:00 x 10-3 mol l-1. The kinetic model and mechanism of the said reaction was proposed by means of mathematical statistical modelling of the dependences of kobs on pH and coxime. The mechanism involves a pre-equilibrium (k -1/k1) in which PNPA forms a tetrahedral intermediate (THI) with the deprotonated form of oxime. In the given medium, THI is in equilibrium with the non-reactive conjugated acid THIH (dissociation constant Ka,THIH) which is stabilized by intramolecular hydrogen bond. Depending on pH, the rate-limiting step consists either in formation of THI from educts (pH a,oxime) or in its spontaneous (k 2) and oxime-catalyzed (k3, general acid catalysis) decomposition to products (pH > pKa/oxime). Evaluation of substituent effects on dissociation constants (Ka,oxime) of the oximes showed that there is no direct conjugation between the substituent and the reaction centre (the found reaction constant ρ(Ka,oxime) = 0.91). The transmission coefficient of the transfer of these effects through C=N-O grouping corresponds approximately to one bond. The reaction constants in the Hammett equation obtained from the regression model are: ρ(k -1Ka,THIH/k1) = 1.29, ρ(k2K a,THIH) = 0.20 and ρ(k3Ka,THIH) = 0.67. These reaction constants have been discussed with the regard to the reaction mechanism suggested.
- Picha, Jan,Cibulka, Radek,Hampl, Frantisek,Liska, Frantisek,Parik, Patrik,Pytela, Oldrich
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p. 397 - 413
(2007/10/03)
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- Regioselective synthesis of syn-oximes using 3A molecular sieves in a solventless system
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Regioselective synthesis of syn-oximes using 3A molecular sieves under solvent-free condition is described.
- Bigdeli, Mohammad A.,Nikje, Mir.M.Alavi,Jafari, Said,Heravi, Majid M.
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- Solvolysis of substituted benzyl azoxyarenesulfonates: Characterisation of the transition state and the selectivity of benzylic intermediates in 50% aqueous 2,2,2-trifluoroethanol
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Thirteen substituted benzyl azoxyarenesulfonates have been prepared and rate constants for solvolysis of twelve have been measured in 50% (v/v) aqueous 2,2,2-trifluoroethanol over a range of temperatures from which activation parameters and rate constants at 25°C have been determined. A six-point Hammett correlation for substituents in the benzylic electrofuge, with azoxytoluene-p-sulfonate as the common nucleofuge, gives ρ(σ+) = -3.27. With 4-methylbenzyl as a common electrofuge, four substituents in the azoxybenzenesulfonate nucleofuge give ρ(σ) = 1.07. Comparison with model reactions indicates a synchronous concerted rate-limiting fragmentation for these substrates. With the less reactive 3-chlorobenzyl as electrofuge, ρ for substituents in the nucleofuge is only ca. 0.7 which indicates a lower degree of charge development in the arenesulfonate in the transition state for these reactions. Product analyses have been carried out for compounds of high, intermediate, and low reactivity. These indicate a reactivity-selectivity relationship for capture of the substituted benzylic electrophiles by water and 2,2,2-trifluoroethanol. Substituted benzaldehydes are formed from the less reactive substrates, indicating trapping of the first-formed benzylic carbenium ion by nitrous oxide and subsequent elimination of nitrogen and a proton; but yields are low and decrease as the substituted benzyl cation becomes increasingly stable.
- Gordon,Maskill
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p. 2059 - 2062
(2007/10/03)
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- A rapid and convenient synthesis of oximes in dry media under microwave irradiation
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In a novel method, the reaction of hydroxylamine hydrochloride with a number of aldehydes and ketones under microwave irradiation and solventless 'dry' condition gave oximes in excellent yield.
- Hajipour, Abdol Reza,Mallakpour, Shadpour E.,Imanzadeh, Gholamhasan
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p. 228 - 229
(2007/10/03)
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- 1H and 13C studies of para-substituted benzaldoximes for evaluation of the electron donor properties of substituted amino groups
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1H and 13C NMR spectra of seventeen (E)-benzaldoximes and three acetophenone oximes, both carrying substituted p-amino groups, have been recorded and discussed from the point of view of substituent effect.The resonance effect of these substituents is not transmitted strongly to CH=NOH group.However, it is found that the chemical shift of Cpara depends linearly on ?R0 values.This dependence has been used to calculate the resonance substituent constants for the less common amino groups and the 1-pyrrolidine group is found to be the most powerful electron donor among the substituents studied.
- Gawinecki, Ryszard,Kolehmainen, Erkki,Kauppinen, Reijo
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- 1H and 13C NMR Studies of some O-Carbamoyloximes
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The 1H and 13C NMR spectra were assigned for a series of O-carbamoyloximes of ortho- and para-substituted benzaldehyde.These compounds exist exclusively in the E configuration.The aromatic protons and carbons show correlations with the appropriate substituent-induced shifts and with Hammett parameters. KEY WORDS O-Carbamoyloximes 1H and 13C NMR Hammett parameters
- Wazeer, Mohammed I. M.,Ali, Sk. A.,Arab, Mohammed
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p. 1102 - 1104
(2007/10/02)
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- Synthesis and Antitubercular Activity of 4-(5-Nitro-2-furyl/2-pyrazinyl/1-adamantyl)-2-(alkyl/aryl/arylamino)thiazoles
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The reaction of haloketones, obtained from Arndt-Eistert reaction on the acid chlorides of 1-adamantane, 5-nitrofuroic acid and pyrazine-2-carboxylic acid, with different thioamides and thioureas affords the title thiazoles (I-III).Some of them exhibit interesting antitubercular activity at 6.25 to 0.38 μg/ml concentration against H37Rv strain of M. tubercolosis in vitro testing.The structure activity relationship (SAR) has also been discussed.
- Khadse, B. G.,Lokhande, S. R.,Bhamaria, R. P.,Prabhu, S. R.
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p. 856 - 860
(2007/10/02)
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- Polarographic Behaviour of Aldoximes in Phenyltrialkylammonium Iodides
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The polarography of a few aromatic aldoximes has been studied in unbuffered 8percent ethanolic medium using phenyltrimethyl- and phenyldimethylammonium iodides as new supporting electrolytes (vs SCE), which are found to be superior to tetralkylammonium ha
- Damle, M. V.,Kaushal, R.,Bhale, A.,Tiwari, M.,Malshe, P.T.
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