- Novel 1,3,4-oxadiazole compounds inhibit the tyrosinase and melanin level: Synthesis, in-vitro, and in-silico studies
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In this research work, we have designed and synthesized some biologically useful of 1,3,4-Oxadiazoles. The structural interpretation of the synthesized compounds has been validated by using FT-IR, LC-MS, HRMS, 1H NMR and 13C NMR techniques. Moreover, the in-vitro mushroom tyrosinase inhibitory potential of the target compounds was assessed. The in-vitro study reveals that, all compounds demonstrate an excellent tyrosinase inhibitory activity. Especially, 2-(5-(2-methoxyphenyl)-1,3,4-oxadiazol-2-ylthio)-N-phenylacetamide (IC50 = 0.003 ± 0.00 μM) confirms much more significant potent inhibition activity compared with standard drug kojic acid (IC50 = 16.83 ± 1.16 μM). Subsequently, the most potent five oxadiazole compounds were screened for cytotoxicity study against B16F10 melanoma cells using an MTT assay method. The survival rate for the most potent compound was more pleasant than other compounds. Furthermore, the western blot results proved that the most potent compound considerably decreased the expression level of tyrosinase at 50 μM (P 0.05). The molecular docking investigation exposed that the utmost potent compound displayed the significant interactions pattern within the active region of the tyrosinase enzyme and which might be responsible for the decent inhibitory activity towards the enzyme. A molecular dynamic simulation experiment was presented to recognize the residual backbone stability of protein structure.
- Vanjare, Balasaheb D.,Choi, Nam Gyu,Mahajan, Prasad G.,Raza, Hussain,Hassan, Mubashir,Han, Yohan,Yu, Seon-Mi,Kim, Song Ja,Seo, Sung-Yum,Lee, Ki Hwan
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- Synthesis and biological evaluation of honokiol derivatives bearing 3-((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)oxazol-2(3h)-ones as potential viral entry inhibitors against sars-cov-2
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The 2019 coronavirus disease (COVID-19) caused by SARS-CoV-2 virus infection has posed a serious danger to global health and the economy. However, SARS-CoV-2 medications that are specific and effective are still being developed. Honokiol is a bioactive component from Magnoliae officinalis Cortex with damp-drying effect. To develop new potent antiviral molecules, a series of novel honokiol analogues were synthesized by introducing various 3-((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)oxazol-2(3H)-ones to its molecule. In a SARS-CoV-2 pseudovirus model, all honokiol derivatives were examined for their antiviral entry activities. As a result, 6a and 6p demonstrated antiviral entry effect with IC50 values of 29.23 and 9.82 μM, respectively. However, the parental honokiol had a very weak antiviral activity with an IC50 value more than 50 μM. A biolayer interfero-metry (BLI) binding assay and molecular docking study revealed that 6p binds to human ACE2 protein with higher binding affinity and lower binding energy than the parental honokiol. A competitive ELISA assay confirmed the inhibitory effect of 6p on SARS-CoV-2 spike RBD’s binding with ACE2. Importantly, 6a and 6p (TC50 > 100 μM) also had higher biological safety for host cells than honokiol (TC50 of 48.23 μM). This research may contribute to the discovery of potential viral entrance inhibitors for the SARS-CoV-2 virus, although 6p’s antiviral efficacy needs to be validated on SARS-CoV-2 viral strains in a biosafety level 3 facility.
- Bai, Li-Ping,Guo, Yong,Jiang, Zhi-Hong,Liu, Jia-Zheng,Meng, Jie-Ru,Xu, Ting,Zheng, Zhi-Yuan
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- Development of Novel (+)-Nootkatone Thioethers Containing 1,3,4-Oxadiazole/Thiadiazole Moieties as Insecticide Candidates against Three Species of Insect Pests
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To improve the insecticidal activity of (+)-nootkatone, a series of 42 (+)-nootkatone thioethers containing 1,3,4-oxadiazole/thiadiazole moieties were prepared to evaluate their insecticidal activities against Mythimna separata Walker, Myzus persicae Sulzer, and Plutella xylostella Linnaeus. Insecticidal evaluation revealed that most of the title derivatives exhibited more potent insecticidal activities than the precursor (+)-nootkatone after the introduction of 1,3,4-oxadiazole/thiadiazole on (+)-nootkatone. Among all of the (+)-nootkatone derivatives, compound 8c (1 mg/mL) exhibited the best growth inhibitory (GI) activity against M. separata with a final corrected mortality rate (CMR) of 71.4%, which was 1.54- and 1.43-fold that of (+)-nootkatone and toosendanin, respectively; 8c also displayed the most potent aphicidal activity against M. persicae with an LD50 value of 0.030 μg/larvae, which was closer to that of the commercial insecticidal etoxazole (0.026 μg/larvae); and 8s showed the best larvicidal activity against P. xylostella with an LC50 value of 0.27 mg/mL, which was 3.37-fold that of toosendanin and slightly higher than that of etoxazole (0.28 mg/mL). Furthermore, the control efficacy of 8s against P. xylostella in the pot experiments under greenhouse conditions was better than that of etoxazole. Structure-activity relationships (SARs) revealed that in most cases, the introduction of 1,3,4-oxadiazole/thiadiazole containing halophenyl groups at the C-13 position of (+)-nootkatone could obtain more active derivatives against M. separata, M. persicae, and P. xylostella than those containing other groups. In addition, toxicity assays indicated that these (+)-nootkatone derivatives had good selectivity to insects over nontarget organisms (normal mammalian NRK-52E cells and C. idella and N. denticulata fries) with relatively low toxicity. Therefore, the above results indicate that these (+)-nootkatone derivatives could be further explored as new lead compounds for the development of potential eco-friendly pesticides.
- Cheng, Wanqing,Fan, Jiangping,Guo, Yong,Han, Meiyue,Ma, Nannan,Yan, Xiaoting,Yang, Ruige
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p. 15544 - 15553
(2022/01/03)
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- A highly stable all-in-one photocatalyst for aryl etherification: The NiIIembedded covalent organic framework
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The efficient conversion of aryl bromides to the corresponding aryl alkyl ethers by dual nickel/photocatalysis has seen great progress, but difficulties of recycling the photosensitizer or nickel complexes cause problems of sustainability. Here, we report the design of a novel, highly stable vinyl bridge 2D covalent organic framework (COF) containing Ni, which combines the role of photosensitizer and reactive site. The as-prepared sp2c-COFdpy-Ni acts as an efficient heterogeneous photocatalyst for C-O cross coupling. The sp2c-COFdpy-Ni can be completely recovered and used repeatedly without loss of activity, overcoming the limitations of the prior methods. Preliminary studies reveal that strong interlayer electron transfer may facilitate the generation of the proposed intermediate sp2c-COFdpy-NiI in a bimolecular and self-sustained manner. This all-in-one heterogeneous photocatalyst exhibits good compatibility of substrates and tolerance of functional groups. The successful attempt to expand the 2D COFs with this new catalyst into photocatalytic organic transformation opens an avenue for photoredox/transition metal mediated coupling reactions.
- Chen, Hao,Dong, Wenbo,Hu, Jianxiang,Rao, Li,Wang, Pei,Wang, Shengyao,Xiang, Yonggang,Yang, Yi
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p. 5797 - 5805
(2021/08/23)
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- Oxazole ring-containing honokiol thioether derivative and preparation method and application thereof
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The invention discloses an oxazole ring-containing honokiol thioether derivative, a preparation method thereof and application of the oxazole ring-containing honokiol thioether derivative as an alpha-glucosidase inhibitor, the chemical structure of the oxazole ring-containing honokiol thioether derivative is shown as a general formula (I), and R is selected from non-substituted or substituted phenyl. Compared with the prior art, the invention provides the novel honokiol thioether derivative containing the oxazole ring, and the honokiol thioether derivative containing the oxazole ring has good inhibitory activity on alpha-glucosidase, provides more possibilities for treating diabetes, and is expected to be used for preparing novel candidate drug molecules for treating diabetes. In addition, the preparation process is simple, the cost is low, and the yield is high.
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Paragraph 0042-0044
(2021/08/11)
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- Manganese-catalysed transfer hydrogenation of esters
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Manganese catalysed ester reduction using ethanol as a hydrogen transfer agent in place of dihydrogen is reported. High yields can be achieved for a range of substrates using 1 mol% of a Mn(i) catalyst, with an alkoxide promoter. The catalyst is derived from a tridentate P,N,N ligand.
- Oates, Conor L.,Widegren, Magnus B.,Clarke, Matthew L.
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supporting information
p. 8635 - 8638
(2020/08/21)
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- Design, synthesis, biological activity, crystal structure and theoretical calculations of novel 1,2,4-triazole derivatives
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Series of 1,2,4-triazole Schiff base (Ia-f) were designed and synthesized. Their in-vitro antifungal activity to pythium solani, gibberlla nicotiancola, fusarium oxysporium fs.p. niveum and gibberlla saubinetii were evaluated. The results showed compound If exhibited good activity with tested fungi, which indicated that 1,2,4-triazole scaffold with introduction of imidazole phenyl could keep the antifungal activity. In order to further research the compound If, the crystal structure was detected by X-ray diffraction. Meanwhile, the FT-IR, FT-Raman, natural bond orbital (NBO), HOMO-LUMO and MEP were calculated at B3LYP/6-311G+(d,p) level. All the results will be helpful for further drug design in 1,2,4-triazole analogues.
- Jin, Ruyi,Wang, Yanyan,Guo, Hui,Long, Xu,Li, Jiajia,Yue, Shijun,Zhang, Shuan,Zhang, Guanghui,Meng, Qinghua,Wang, Chuan,Yan, Hao,Tang, Yuping,Zhou, Sha
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- 5-substituent-1, 2, 4-triazole-thioketone Schiff base compound as well as preparation method and application thereof
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The invention belongs to the technical field of chemical medicines, and relates to a 5-substituent 1, 2, 4-triazole thioketone Schiff base compound as well as a preparation method and application thereof. An intermediate (I) or an intermediate (II) is subjected to reflux reaction with 3, 5-dimethyl 4-hydroxy benzaldehyde in glacial acetic acid respectively, filtering and drying are performed to obtain the 5-substituent -1, 2, 4-triazole thioketone Schiff base compound. According to the 5-substituent-1, 2, 4-triazole-thioketone Schiff base compound as well as the preparation method and application thereof of the invention, an active group-- imino is introduced into a triazole ring matrix to prepare and synthesize a series of triazole Schiff base compounds with multiple active sites, and thetriazole Schiff base compounds have the advantages of good activity, small dosage, small toxic and side effects, safety and environmental protection; meanwhile, the compounds can be used as crop antifungal agents and can influence the synthesis of fungal cell walls, so that the growth and proliferation of fungi are inhibited, and finally, an antibacterial or bactericidal effect is achieved.
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Paragraph 0100; 0103
(2021/01/04)
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- Carbonylative Suzuki coupling and alkoxycarbonylation of aryl halides using palladium supported on phosphorus-doped porous organic polymer as an active and robust catalyst
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Developing highly active catalysts with the combined advantages of molecular and solid catalysis is considered as the “Holy Grail” in the area of catalysis research. Herein, a phosphorus-doped porous polymer-immobilized palladium was successfully developed as an efficient, robust, and recyclable catalyst for the carbonylative Suzuki coupling and alkoxycarbonylation reactions of aryl halides. Rather than just as an immobilizing molecular catalyst, palladium supported on phosphorus-doped porous organic polymer exhibits even better catalytic performances than that of its analogue homogeneous catalysts in both carbonylation reactions. Moreover, the catalyst can be easily separated and reused for at least 5 times without significant loss in reactivity. Importantly, the catalyst was highly stable under carbonylation reaction conditions, and no palladium nanoparticle was observed even after the 5th reuse.
- Wan, Yali,Song, Fangxiang,Ye, Tao,Li, Guangxing,Liu, Dingfu,Lei, Yizhu
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- Construction of Esters through Sulfuryl Fluoride (SO 2 F 2) Mediated Dehydrative Coupling of Carboxylic Acids with Alcohols at Room Temperature
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A facile method for the construction of esters through dehydrative coupling of carboxylic acids with alcohols is developed. The reactions are mediated by sulfuryl fluoride (SO 2 F 2) at room temperature and proceed with high efficiency. The method has several advantages including broad substrate scope, mild conditions, excellent functional group compatibility and affords high yields, even on gram scale.
- Qin, Hua-Li,S Alharbi, Njud,Wang, Shi-Meng
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p. 3901 - 3907
(2019/10/11)
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- Synthesis and bioactivity of sulfide derivatives containing 1,3,4-oxadiazole and pyridine
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A series of novel sulfide derivatives containing 1,3,4-oxadiazole and pyridine were synthesized, characterized, and tested for their antibacterial activity against tobacco bacterial wilt and rice bacterial blight and for insecticidal activity toward diamondback moth. The results showed that some compounds had good insecticidal and bactericidal activity, e.g., the activities of compounds 6e and 6g–6j toward tobacco bacterial wilt were much better than those of commercial thiodiazole-copper, and some of the synthesized compounds possessed good insecticidal activity against Plutella xylostella. Compounds 6d, 6h, 6j, 6l, 6p, 6r, and 6p displayed over 93% activity at 500 mg L? 1.
- Yu, Gang,Chen, Shunhong,He, Feng,Luo, Dexia,Zhang, Yu,Wu, Jian
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p. 1075 - 1085
(2019/09/10)
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- Design and synthesis of new norfloxacin-1,3,4-oxadiazole hybrids as antibacterial agents against methicillin-resistant Staphylococcus aureus (MRSA)
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Toward the search of new antibacterial agents to control methicillin-resistant Staphylococcus aureus (MRSA), a class of new norfloxacin-1,3,4-oxadiazole hybrids were designed and synthesized. Antibacterial activities against drug-sensitive bacteria S. aureus and clinical drug resistant isolates of MRSA were evaluated. Compound 5k exhibited excellent antibacterial activities against S. aureus (MIC: 2 μg/mL) and MRSA1–3 (MIC: 0.25–1 μg/mL). The time-kill kinetics demonstrated that compound 5k had an advantage over commonly used antibiotics vancomycin in killing S. aureus and MRSA. Moreover, compound 5k could inhibit the bacteria and destroy their membranes in a short time, and showed very low cytotoxicity to NRK-52E cells. Some interesting structure-activity relationships (SARs) were also discussed. These results indicated that these norfloxacin-1,3,4-oxadiazole hybrids could be further developed into new antibacterial agents against MRSA.
- Guo, Yong,Xu, Ting,Bao, Chongnan,Liu, Zhiyan,Fan, Jiangping,Yang, Ruige,Qin, Shangshang
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- Investigation on 4-amino-5-substituent-1,2,4-triazole-3-thione Schiff bases an antifungal drug by characterization (spectroscopic, XRD), biological activities, molecular docking studies and electrostatic potential (ESP)
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Four novel Schiff bases 4-(2,4-dinitrobenzylideneamino)-5-m-tolyl-2H-1,2,4-triazole-3(4H)-thione) (F1), 4-(2,4-dinitrobenzylideneamino)-5-(2-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione) (F2), 4-(2,4-dinitrobenzylideneamino)-5-(3-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione) (F3) and 4-(2,4-dinitrobenzylideneamino)-5-(4-methoxyphenyl)-2H-1,2,4-triazole-3(4H)-thione) (F4) were prepared as new antifungal compounds contributing 4-Amino-5-Substituent-1,2,4-Triazole-3-Thione and 2,4-dinitrobenzaldehyde via a condensation reaction under the mild conditions with excellent yields. The structures of compounds were characterized by elemental analysis (EA), FT-IR, 1H NMR, 13C NMR spectra and X-ray analysis. In addition, the compounds were screened for in vitro biological activity, and the bioassay results indicated that the newly synthesized compounds showed different in vitro antifungal activities against five plant fungi. Particularly, compound F3 (EC50 = 11.16 mg/L) was found to be the most active respectively against Wheat gibberellic, even more effective than Fluconazole (EC50 = 16.03 mg/L). The active compounds were further evaluated for enzyme inhibition efficacy against the receptor CYP51 by docking. Meanwhile, an explicit surface analysis on compounds were carried out theoretically using the wave function analyzer (Multiwfn 3.4.1 software) in order to study the reactivity of the compounds.
- Wu, Shaojie,Zhang, Wenhui,Qi, Le,Ren, Yinghui,Ma, Haixia
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p. 171 - 182
(2019/07/19)
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- Design, synthesis, insecticidal activity and 3D-QSR study for novel trifluoromethyl pyridine derivatives containing an 1,3,4-oxadiazole moiety
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A series of trifluoromethyl pyridine derivatives containing 1,3,4-oxadiazole moiety was designed, synthesized and bio-assayed for their insecticidal activity. The result of bio-assays indicated the synthesized compounds exhibited good insecticidal activity against Mythimna separata and Plutella xylostella, most of the title compounds show 100% insecticidal activity at 500 mg L-1 and >80% activity at 250 mg L-1 against the two pests. Compounds E18 and E27 showed LC50 values of 38.5 and 30.8 mg L-1 against Mythimna separata, respectively, which were close to that of avermectin (29.6 mg L-1); compounds E5, E6, E9, E10, E15, E25, E26, and E27 showed 100% activity at 250 mg L-1, which were better than chlorpyrifos (87%). CoMFA and CoMSIA models with good predictability were proposed, which revealed the electron-withdrawing groups with an appropriate bulk at 2- and 4-positions of benzene ring could enhance insecticidal activity.
- Xu,Wang,Luo,Yu,Guo,Fu,Zhao,Wu
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p. 6306 - 6314
(2018/02/19)
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- Design, synthesis, biological activities and DFT calculation of novel 1,2,4-triazole Schiff base derivatives
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Series of 1,2,4-triazole Schiff bases (2a-2d, 2f-2h and 3a-3h) have been designed and synthesized. The structure of title compounds was confirmed on the basis of their spectral data and elemental analysis. All the target compounds were screened for their in vitro antifungal activity and antibacterial activity. Two of the tested compounds (2a and 2b) exhibited significant antifungal activity against most fungi, especially compound 2a showed better antifungal activity than triadimefon. Meanwhile, the antibacterial activity assay also indicated compound 2a exhibited excellent antibacterial activities comparable to chloramphenicol. The SAR manifested no substitution at position 5 of the triazole ring caused an increase in activity, and 3-phenoxy phenyl group introduced in 1,2,4-triazole scaffold can enhance the antibacterial activity. The DFT calculation indicated triazole ring, S atom and benzene ring in both of the 2a and 3a make a major contribution to the activity.
- Jin, Ru-Yi,Zeng, Chu-Yue,Liang, Xu-Hua,Sun, Xiao-Hong,Liu, Yuan-Fa,Wang, Yan-Yan,Zhou, Sha
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p. 253 - 260
(2018/07/06)
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- N-(5-Methyl-1,3-Thiazol-2-yl)-2-{[5-((Un)Substituted- Phenyl)1,3,4-Oxadiazol-2-yl]Sulfanyl}acetamides. Unique Biheterocycles as Promising Therapeutic Agents
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An electrophile, 2-bromo-N-(5-methyl-1,3-thiazol-2-yl)acetamide, was synthesized by the reaction of 5-methyl-1,3-thiazol-2-amine and bromoacetyl bromide in an aqueous medium. In a parallel scheme, a series of (un)substituted benzoic acids was converted sequentially into respective esters, acid hydrazides, and then into 1,3,4-oxadiazole heterocyclic cores. The electrophile was coupled with the aforementioned 1,3,4-oxadiazoles to obtain the targeted bi-heterocyles. Structural analysis of the synthesized compounds was performed by IR, EI-MS, 1H NMR, and 13C NMR. The enzyme inhibition study of these molecules was carried out against four enzymes, namely, acetylcholinesterase, butyrylcholinesterase, α-glucosidase, and urease. The interactions of these compounds with respective enzymes were recognized by their in silico study. Moreover, their cytotoxicity was also determined to find out their utility as possible therapeutic agents.
- Abbasi,Ramzan,Aziz-ur-Rehman,Siddiqui,Shah,Hassan,Seo,Ashraf,Mirza,Ismail
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p. 801 - 811
(2019/02/27)
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- Chemoselective and Metal-Free Synthesis of Aryl Esters from the Corresponding Benzylic Alcohols in Aqueous Medium Using TBHP/TBAI as an Efficient Catalytic System
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A novel and transition-metal-free strategy has been developed for the synthesis of aryl esters starting from corresponding benzylic primary alcohols as the exclusive substrates using tert -butyl hydroperoxide (TBHP) as a terminal oxidant in the presence of catalytic amount of tetrabutylammonium iodide (TBAI) and imidazole, where the aliphatic alcohols remained unaffected. These reactions are highly chemoselective and associated with high yield and wide applicability accommodating a wide range of substituents. Excellent chemoselectivity has also been demonstrated through intramolecular competition experiments. This protocol can be considered as an important analogue of Tishchenko reaction using benzylic alcohols as the substrates instead of benzaldehydes.
- Nandy, Sneha,Ghatak, Avishek,Das, Asit Kumar,Bhar, Sanjay
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p. 2208 - 2212
(2018/10/02)
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- Facile, highly efficient and environmentally friendly transesterification mediated by platinum dioxide and nickel oxide under essentially neutral conditions
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A practical, facile and highly efficient transesterification reaction under essentially neutral conditions was achieved using platinum dioxide (PtO2) or PtO2/nickel oxide (NiO) as the catalyst. A number of esters and alcohols that contain various functional groups were employed. Good to excellent yields were obtained for different aromatic or aliphatic starting materials. The Pt-alcohol intermediate generated in situ facilitated the exchange of low-alcohol esters to high-alcohol esters.
- Teng, Binhao,Shi, Jiangong,Yao, Chunsuo
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supporting information
p. 2465 - 2471
(2018/06/11)
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- Synthesis of Hydroxybenzoic Acids and Their Esters by Reaction of Phenols with Carbon Tetrachloride and Alcohols in the Presence of Iron Catalysts
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Alkyl esters of hydroxy-, methoxy-, and ethoxybenzoic and cresotic acids have been synthesized by reaction of phenols, anisole, phenetole, and cresols with carbon tetrachloride and alcohols in the presence of iron catalysts.
- Bayguzina,Tarisova,Khusnutdinov
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p. 208 - 215
(2018/03/26)
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- Diethyloxalate as “CO” Source for Palladium-Catalyzed Ethoxycarbonylation of Bromo- and Chloroarene Derivatives
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Palladium(II)-catalyzed ethoxycarbonylation of aryl bromides with diethyloxalate oxalate is described. Functionalized aromatic esters can be efficiently synthesized with only 0.65 mol % PdCl2(PPh3)2 catalyst under microwav
- Monrose, Amandine,Salembier, Helori,Bousquet, Till,Pellegrini, Sylvain,Pélinski, Lydie
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supporting information
p. 2699 - 2704
(2017/08/16)
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- Solvent- and Metal-free Oxidative Esterification of Aromatic Aldehydes Using Urea-2,2-dihydroperoxypropane as a New Solid Oxidant
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Urea-2,2-dihydroperoxypropane as a noble and solid gem-dihydroperoxide derivative was used to transform various aromatic aldehydes to their corresponding benzoate derivatives in the presence of HBr under mild conditions at room temperature in high yields and short reaction times.
- Khosravi, Kaveh,Khalaji, Kobra,Naserifar, Shirin
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p. 303 - 309
(2017/03/27)
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- Noncovalent Interactions in Ir-Catalyzed C-H Activation: L-Shaped Ligand for Para-Selective Borylation of Aromatic Esters
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An efficient strategy for the para-selective borylation of aromatic esters is described. For achieving high para-selectivity, a new catalytic system has been developed modifying the core structure of the bipyridine. It has been proposed that the L-shaped ligand is essential to recognize the functionality of the oxygen atom of the ester carbonyl group via noncovalent interaction, which provides an unprecedented controlling factor for para-selective C-H activation/borylation.
- Hoque, Md Emdadul,Bisht, Ranjana,Haldar, Chabush,Chattopadhyay, Buddhadeb
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supporting information
p. 7745 - 7748
(2017/06/21)
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- Synthesis, structural studies and biological activities of three new 2-(pentadecylthio)-5-aryl-1,3,4-oxadiazoles
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1,3,4-Oxadiazoles are important class of heterocyclic compounds, with diverse biological applications. In this study, the synthesis of three different 1,3,4-oxadiazoles bearing pentadecyl moiety is reported. All compounds were synthesized with significant (70–82%) yields, characterized by using different spectroanalytical techniques such as UV–vis., FT-IR, NMR (1H and 13C), and finally structures were confirmed unequivocally by single crystal X-ray diffraction analysis. Quantum chemical studies by using GAUSSIAN software at DFT/B3LYP/6-31G (d, p) level of theory have been exercised to compare and validate the spectroscopic and X-ray results. Frontier molecular orbitals (FMOs) analysis of all compounds was performed by utilizing optimized geometries and gave the idea about kinetic stability and reactivity. Molecular electrostatic potential (MEP) analysis indicated the regions for electrophilic as well as nucleophilic attack. Compounds were also screened to check their antibacterial and antifungal potential.
- Ahmed, Muhammad Naeem,Yasin, Khawaja Ansar,Hameed, Shahid,Ayub, Khurshid,Haq, Ihsan-ul,Tahir, M. Nawaz,Mahmood, Tariq
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- Design, synthesis, biological evaluation, and 3D-QSAR analysis of podophyllotoxin–dioxazole combination as tubulin targeting anticancer agents
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The advancement of cancer-fighting drugs has never been a simple linear process. Those drug design professionals begin to find inspiration from the nature after failing to find the ideal products by creative drug design and high-throughput screening. To obtain new molecules for inhibiting tubulin, podophyllotoxin was adopted as the leading compound and 1,3,4-oxadiazole was brought in to the C-4 site of podophyllotoxin in this research. A series of seventeen podophyllotoxin-derived esters have been achieved and then evaluated their antitumor activities against four different cancer cell lines: A549, MCF-7, HepG2, and HeLa. Among all the compounds, compound 7c showed the best antiproliferating properties with IC50?=?2.54?±?0.82?μm against MCF-7 cancer cell line. It was obvious that the content of ROS grew significantly in MCF-7 in a way depending on the dosage. The time- and dose-dependent cell cycle assays revealed that compound 7c could apparently block cell cycle in the phase of G2/M along with the upregulation of cyclin A2 and CDK2 protein. According to further studies, confocal microscopy experiment has certified that compound 7c could restrain cancer from growing by blocking the polymerization of microtubule. Meanwhile, compound 7c could be ideally integrated with the colchicine site of tubulin. In future, it would be feasible to selectively design tubulin inhibitors with the help of 3D-QSAR. This means that it is hopeful to develop compound 7c as a potential agent against cancer due to its biological characteristics.
- Wang, Zi-Zhen,Sun, Wen-Xue,Wang, Xue,Zhang, Ya-Han,Qiu, Han-Yue,Qi, Jin-Liang,Pang, Yan-Jun,Lu, Gui-Hua,Wang, Xiao-Ming,Yu, Fu-Gen,Yang, Yong-Hua
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p. 236 - 243
(2017/07/13)
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- Synthesis, spectral analysis and antibacterial evaluation of 5-substituted-1,3,4-oxadiazol-2-yl 4-(4-methylpiperidin-1-ylsulfonyl)benzyl sulfides
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Owing to valuable biological activities of 1,3,4-oxadiazole, sulfamoyl and piperidine functionalities, some new 1-(4-{[(5-substituted-1,3,4-oxadiazol-2-yl) thio]methyl}benzene sulfonyl)-4-methylpiperidine (6a-o) derivatives have been introduced. The target molecules were synthesized from different aralkyl/aryl carboxylic acids, 1a-o, through a series of steps. First the compounds, 1a-o, were converted to heterocyclic 1,3,4-oxadiazole nucleophiles, 4a-o. Second an electrophile as 1-(4-bromomethylbenzenesulfonyl)-4-methylpiperidine (5) was synthesized from 4-methylpiperidine. Finally the target compounds, 6a-o, were prepared by reacting 4a-o with 5 in DMF and LiH. The final compounds were structurally elucidated by spectral data of IR, 1H-NMR and EI-MS. All the compounds were screened for their antibacterial evaluation and found to exhibit valuable results.
- Aziz-Ur-Rehman,Ahtzaz, Samreen,Abbasi, Muhammad Athar,Siddiqui, Sabahat Zahra,Rasool, Shahid,Ahmad, Irshad
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p. 3370 - 3375
(2017/05/22)
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- Synthesis and pharmacological screening: Sulfa derivatives of 2-pipecoline-bearing 1,3,4-oxadiazole core
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An electrophile, 1-(4-(bromomethylbenzenesulfonyl)-2-methylpiperidine, was synthesized by the reaction of 2-methylpiperidine (2-pipecoline) and 4-bromomethylbenzenesulfonyl chloride in a weak basic medium under pH control. A series of nucleophiles, 5-aryl/aralkyl-1,3,4-oxadiazol-2-thiols, were synthesized from corresponding carboxylic acids in three steps. The title molecules were synthesized by coupling the electrophile to nucleophiles in an aprotic medium using LiH as an activator. The structures of all synthesized compounds were corroborated through IR, 1H NMR, and EI-MS techniques. All the compounds were screened for their pharmacological behavior, particularly, antibacterial and enzyme inhibitory activities. Notably efficient results were obtained against both gram-positive and gram-negative bacterial strains. Regarding enzyme inhibition, compounds were efficient against acetylcholinesterase and butyrylcholinesterase.
- Aziz-ur-Rehman,Arif,Abbasi,Siddiqui,Rasool,Shah
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p. 328 - 339
(2017/07/04)
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- Synthesis of novel triazoles and a tetrazole of escitalopram as cholinesterase inhibitors
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A novel serie of escitalopram triazoles (60-88) and a tetrazole (89) have been synthesized and subjected to a study to establish the inhibitory potential of these compounds toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Some selectivity in inhibition has been observed. The 4-chlorophenyl- (75, IC50, 6.71 ± 0.25 μM) and 2-methylphenyl- (70, IC50, 9.52 ± 0.23 μM) escitalopram triazole derivatives depicted high AChE inhibition, while 2-fluorophenyl- (76, IC50 = 4.52 ± 0.17 μM) and 4-fluorophenyl- (78, IC50 = 5.31 ± 0.43 μM) have found to be excellent BChE inhibitors. It has also been observed that ortho, meta and para substituted electron donating groups increase the inhibition, while electron withdrawing groups reduce the inhibition. Docking analyses of inhibitors with AChE have depicted the binding energies for 70 and 75 as ΔGbind -6.42 and -6.93 kcal/mol, respectively, while ligands 76 and 78 have shown the binding affinity ΔGbind -9.04 and -8.51 kcal/mol, respectively, for BChE.
- Mehr-Un-Nisa,Munawar, Munawar A.,Chattha, Fauzia A.,Kousar, Samina,Munir, Jawaria,Ismail, Tayaba,Ashraf, Muhammad,Khan, Misbahul A.
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p. 6014 - 6024
(2015/11/11)
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- Palladium-Catalyzed Carbonylations of Arylboronic Acids: Synthesis of Arylcarboxylic Acid Ethyl Esters
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An approach for the palladium-catalyzed ethoxycarbonylations of arylboronic acids using diethyl pyrocarbonate as carbon monoxide/carbon dioxide (CO/CO2) surrogate in moderate to good yields has been investigated.
- Liang, Apeng,Han, Shuaijun,Wang, Liang,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
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supporting information
p. 3104 - 3108
(2015/11/03)
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- Polymer supported Pd catalyzed carbonylation of aryl bromides for the synthesis of aryl esters and amides
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A polymer-anchored palladium(ii) catalyst was synthesized and characterized using various spectroscopic techniques. Its catalytic activity was evaluated for the alkoxycarbonylation and aminocarbonylation reactions. These carbonylation reactions were carried out for various substituted aryl bromides using alcohols and amines. Both the reactions were optimized by varying the bases, temperature and solvents. These experiments were carried out under high CO pressure. The catalyst was very stable and can be facilely recovered and reused six times without a significant decrease in its activity and selectivity. the Partner Organisations 2014.
- Islam, Sk Manirul,Ghosh, Kajari,Roy, Anupam Singha,Molla, Rostam Ali
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p. 38986 - 38999
(2014/11/07)
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- Methyl salicylate as a selective methylation agent for the esterification of carboxylic acids
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Methyl salicylate is a selective and inexpensive methylating agent for the esterification of carboxylic acids with a wide range of functional group tolerance. The intramolecular hydrogen bonds between the carboxylate and hydroxyl groups in methyl salicylate are essential for the transformation. Allyl, benzyl, methallyl, and propargyl salicylates can also be used as alkylating agents for the preparation of the corresponding alkyl carboxylates.
- Chen, Si,Jia, Lei,Li, Xiaonan,Luo, Meiming
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p. 263 - 268
(2014/03/21)
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- Novel 1,3,4-oxadiazole thioether derivatives targeting thymidylate synthase as dual anticancer/antimicrobial agents
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A series of novel 1,3,4-oxadiazole thioether derivatives (compounds 9-44) were designed and synthesized as potential inhibitors of thymidylate synthase (TS) and as anticancer agents. The in vitro anticancer activities of these compounds were evaluated against three cancer cell lines by the MTT method. Among all the designed compounds, compound 18 bearing a nitro substituent exhibited more potent in vitro anticancer activities with IC50 values of 0.7 ± 0.2, 30.0 ± 1.2, 18.3 ± 1.4 μM, respectively, which was superior to the positive control. In the further study, it was identified as the most potent inhibitor against two kinds of TS protein (for human TS and Escherichia coli TS, IC50 values: 0.62 and 0.47 μM, respectively) in the TS inhibition assay in vitro and the most potent antibacterial agents with MIC (minimum inhibitory concentrations) of 1.56-3.13 μg/mL against the tested four bacterial strains. Molecular docking and 3D-QSAR study supported that compound 18 can be selected as dual antitumor/antibacterial candidate in the future study.
- Du, Qian-Ru,Li, Dong-Dong,Pi, Ya-Zhou,Li, Jing-Ran,Sun, Jian,Fang, Fei,Zhong, Wei-Qing,Gong, Hai-Bin,Zhu, Hai-Liang
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p. 2286 - 2297
(2013/05/09)
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- Design, synthesis and biological evaluation of novel arylidine- malononitrile derivatives as non-carboxylic inhibitors of protein tyrosine phosphatase 1B
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In this study, we describe the design, synthesis, biological evaluation and molecular modelling studies of novel non-carboxylic arylidine malononitrile-based molecules as Protein Tyrosine Phosphatase 1B (PTP1B) inhibitors. The synthesized derivatives were evaluated in vitro for glucose reuptake using L6 muscle cell lines and enzymatic assay against PTP1B. The biological activity results showed that the 2-methoxy substituted (14b) compound exhibited significant activity in both the assays. The unsubstituted compound (14a) also possessed comparable activity on glucose reuptake in L6 muscle cell lines and better inhibitory activity on PTP1B enzyme assays. Docking analysis was performed on the most potent compound of the series to understand the nature of interactions governing the binding of the designed molecule with the PTP1B enzyme.
- Deora, Girdhar Singh,Karthikeyan, Chandrabose,Moorthy, N. S. Hari Narayana,Rathore, Vandana,Rawat, Arun K.,Tamrakar, Akhilesh K.,Srivastava,Trivedi, Piyush
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p. 5344 - 5348
(2013/12/04)
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- An unusual 1,2-aryl shift in palladium-catalyzed cross-coupling ethoxycarbonylation of arylboronic acids with α-iminoesters
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The Pd-catalyzed cross-coupling ethoxycarbonylation of aryl boronic acids with N-aryl-α-iminoesters affords aryl carboxylic esters via carbonyl-imino σ bond cleavage. This unprecedented mode of reaction allows regioselective installation of the ethoxycarbonyl group into target molecules. Mechanism studies have revealed that an unusual 1,2-aryl shift process is involved in the transformation. The Royal Society of Chemistry.
- Qian, Cheng,Chen, Jiayan,Fu, Meiqin,Zhu, Shiya,Chen, Wen-Hua,Jiang, Huanfeng,Zeng, Wei
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p. 6013 - 6022
(2013/09/12)
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- Synthesis using microwave irradiation, characterisation and antibacterial activity of Novel deoxycholic acid-triazole conjugates
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Novel deoxycholic acid 3α-triazole conjugates based on methyl 3α-chloroacetoxy-12α-hydroxy-cholanate have been synthesised. The synthesis is accelerated by microwave irradiation under solvent free conditions in the presence of K2CO3. Some of these compounds were tested for antibacterial activity against B.subtilis, P.aeruginosa and S.aureus. The preliminary results indicated that these deoxycholic acid-triazole conjugates have good inhibitory effect against B.subtilis. All of the compounds were characterised by 1H NMR, IR, ESI-MS spectra and elemental analyses.
- Yang, Jie,Zhao, Zhigang,Li, Hui
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scheme or table
p. 383 - 386
(2012/10/08)
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- Acylative cleavage of ethers with ZnCl2
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Acylative cleavage of common ether solvents with ZnCl2 was reported. Different substituted acyl chlorides were reacted with the common ether solvents in the presence of ZnCl2 to obtain the corresponding substituted benzoate.
- Yu, Yun-Feng,Gao, Jian-Rong,Jiang, Shao-Liang,Han, Liang,Jia, Jian-Hong,Li, Yu-Jin
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experimental part
p. 5199 - 5201
(2012/09/21)
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- Continuous-flow, palladium-catalysed alkoxycarbonylation reactions using a prototype reactor in which it is possible to load gas and heat simultaneously
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A prototype tube-in-tube reactor in which it is possible to load gas and heat simultaneously has been used in a continuous-flow approach to alkoxycarbonylation reactions of aryl iodides. In the stainless steel coil, liquid flows on the outside of a gas-permeable membrane. The coil can be heated and the temperature can be measured accurately via a probe touching the outer steel surface. A range of aryl iodides can be transformed to the corresponding esters in excellent conversion by reaction at 120 °C using 0.5 mol% palladium acetate as the catalyst with no additional ligand required. Small-scale optimization and substrate screening runs were followed by scale-up.
- Mercadante, Michael A.,Leadbeater, Nicholas E.
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experimental part
p. 6575 - 6578
(2011/11/05)
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- A continuous-flow approach to palladium-catalyzed alkoxycarbonylation reactions
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Using a continuous-flow approach, it is possible to perform alkoxycarbonylation reactions of aryl iodides. Optimized reactor design allows for adequate mixing of gaseous and liquid reagents. Reactions are performed at rates of around 3 mL/min and at concentrations of 1 M, allowing for significant volumes to be processed per unit time. Palladium acetate (0.5 mol %) is used as the catalyst without the need for an additional ligand.
- Kelly, Christopher B.,Lee, Christopher,Mercadante, Michael A.,Leadbeater, Nicholas E.
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experimental part
p. 717 - 720
(2011/12/01)
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- Synthesis of novel arylhydrazide molecular tweezer artificial receptors based on deoxycholic acid using microwave irradiation
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Eleven novel molecular tweezer anion receptors based on deoxycholic acid have been synthesised using microwave irradiation. Their structures were established by 1H NMR, IR, MS spectra and elemental analysis. Their binding properties were examined by UV-Vis spectra titration. The preliminary results indicate that these molecular tweezers show good recognition properties for H2PO4-, CH3COO- and NO3-.
- Li, Xiaorui,Zhao, Zhigang,Cheng, Yuyu,Li, Hui
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experimental part
p. 234 - 237
(2011/07/08)
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- Preparation of novel molecular tweezers based on 3,6-O-(2- acylhydrazinocarbonyl) esters of hyodeoxycholic acid using microwave irradiation
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Ten novel molecular tweezers based on the 3,6-O-(2-acylhydrazinocarbonyl) esters of hyodeoxycholic acid have been synthesised using microwave irradiation. Their structures were established by 1H NMR, IR, MS spectra and elemental analysis. Their binding properties were examined by UV-Vis spectra titration. The preliminary results indicate that these molecular tweezers show good recognition properties for Cl-, Br-, I-.
- Li, Xiaorui,Qiu, Liying,Mei, Qinggang,Bi, Qingwei,Zhao, Zhigang
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scheme or table
p. 364 - 367
(2011/10/05)
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- Direct conversion of acetals to esters with high regioselectivity via O,P-acetals
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A new direct conversion of O,O-acetals to esters via O,P-acetal intermediates was developed. The regioselective cleavage of unsymmetrical cyclic acetals occurred to give the more crowded esters as single isomers.
- Maegawa, Tomohiro,Otake, Kazuki,Goto, Akihiro,Fujioka, Hiromichi
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p. 5648 - 5651
(2011/09/15)
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- Base-induced mechanistic variation in palladium-catalyzed carbonylation of aryl iodides
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A mechanism, which is distinct from the traditional one when sodium alkoxide was used instead of tertiary amines, was proposed for the alkoxycarbonylation of aryl iodides. The catalytic cycle was composed of oxidative addition, subsequent ArPdOR formation, CO insertion to Pd-OR, and final reductive elimination of ArPdCOOR. The kinetic simultaneity of the formation of deiodinated side product from the aryl iodide and aldehyde from corresponding alcohol provided strong evidence for the existence of ArPdOR species. The observation of thioether, as the other competitive product in palladium catalyzed thiocarbonylation of aryl iodides and sodium alkylthiolate, also indicate the possibility of metathesis between ArPdl and sodium alkylthiolate. Preliminary kinetic studies revealed that neither oxidative addition nor reductive elimination was rate limiting. DFT calculation displayed preference for CO insertion into Pd-OR bond. The advantage of this novel mechanism had been demonstrated in the facile alkoxycarbonylation and thiocarbonylation. The ethoxycarbonylation of aryl iodides under room temperature and balloon pressure of CO in the presence of EtONa were examined, and good to high yields were obtained; the t-butoxycarbonylation reactions in the presence of t-BuONa were achieved, and the alkylthiocarbonylation (including the t-butylthiocarbonylation) of aryl iodides in the presence of sodium alkylthiolate were also investigated.
- Hu, Yanhe,Liu, Jing,Lu, Zhixin,Luo, Xiancai,Zhang, Heng,Lan, Yu,Lei, Aiwen
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supporting information; experimental part
p. 3153 - 3158
(2010/05/15)
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- Synthesis and structural characterisation of 2,4-bis(5-aryl-1,3,4-oxdiazol- 2-yl) pyridine derivatives
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A convenient synthesis of 2,4-bis (5-aryl-1,3,4-oxdiazol-2-yl) derivatives of pyridine by the POCl3-mediated cyclodehydration of a variety of pyridine-2,4-dicarboxylic dihydrazides has been developed. The 20 novel intermediates and target molecules were characterised by IR, 1H NMR, MS and elemental analysis.
- Wang, Xiao Qing,Zhao, Zhi Gang,Liu, Xing Li,Li, Wei Jie
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experimental part
p. 307 - 309
(2010/10/21)
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- Design and synthesis of novel molecular tweezer anion receptors based on diphenic acid carbonyl thiosemicarbazide
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Ten novel molecular tweezer anion receptors based on diphenic acid carbonyl thiosemicarbazide have been designed and synthesised in high yield and their binding properties were examined by UV-Vis spectra titration. Their structures were characterised by 1H NMR, IR, MS spectra and elemental analysis.
- Li, Xiaorui,Zhao, Zhigang,Li, Guohua,Shi, Peiyu
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experimental part
p. 410 - 413
(2010/12/19)
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- Synthesis, biological evaluation, and molecular docking studies of 2-chloropyridine derivatives possessing 1,3,4-oxadiazole moiety as potential antitumor agents
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A series of new 2-chloropyridine derivatives possessing 1,3,4-oxadiazole moiety were synthesized. Antiproliferative assay results indicated that compounds 6o and 6u exhibited the most potent activity against gastric cancer cell SGC-7901, which was more potent than the positive control. Especially, compound 6o exhibited significant telomerase inhibitory activity (IC 50 = 2.3 ± 0.07 μM), which was comparable to the positive control ethidium bromide. Docking simulation was performed to position compound 6o into the active site of telomerase (3DU6) to determine the probable binding model.
- Zheng, Qing-Zhong,Zhang, Xiao-Min,Xu, Ying,Cheng, Kui,Jiao, Qing-Cai,Zhu, Hai-Liang
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scheme or table
p. 7836 - 7841
(2011/01/13)
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- New class of potent antitumor acylhydrazone derivatives containing furan
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A pair of chemical isomeric structures of N-acylhydrazone compounds I and II were designed and synthesized. The reaction was carried out with high diastereoselectivity to obtain one configurational isomer in excellent yields. The exact configuration and conformation of IIa and IIe were confirmed by the X-ray single crystal diffraction. The antitumor bioassay revealed that some compounds exhibited excellent activity against the selected cancer cell lines. In particular, IIf (IC50 = 16.4 μM) was better than doxorubicin (IC50 = 53.3 μM) against human promyelocytic leukemic cells (HL-60). Their toxicities were predicted in silico. The results showed that compounds II were safe and eligible to be development candidates. IIf showed great promise as a novel lead compound for further anticancer discovery.
- Cui, Zining,Li, Ying,Ling, Yun,Huang, Juan,Cui, Jingrong,Wang, Ruiqing,Yang, Xinling
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scheme or table
p. 5576 - 5584
(2011/02/22)
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- Application of a batch microwave unit for scale-up of alkoxycarbonylation reactions using a near-stoichiometric loading of carbon monoxide
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The ethoxycarbonylation of iodobenzene was performed on the 1 mol scale in batch mode using microwave heating. The reaction was performed using both an excess and a near stoichiometric loading of carbon monoxide, comparable yields being obtained. Six different alkoxycarbonylation reactions were then performed simultaneously on the 50 mmol scale using a near-stoichiometric loading of carbon monoxide with excellent conversions in each case.
- Iannelli, Mauro,Bergamelli, Fabio,Kormos, Chad M.,Paravisi, Stefano,Leadbeater, Nicholas E.
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experimental part
p. 634 - 637
(2010/04/22)
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- Alkoxycarbonylation of aryl iodides using gaseous carbon monoxide and pre-pressurized reaction vessels in conjunction with microwave heating
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The microwave-promoted alkoxycarbonylation of aryl iodides using reaction vessels pre-pressurized with carbon monoxide is reported. Reactions are performed using 0.1 mol% palladium acetate as catalyst, DBU as base and are complete within 20-30 min. A range of aryl iodide substrates can be converted to the corresponding esters using this methodology. Primary and secondary alcohols work well whereas a tertiary alcohol substrate proves less reactive. The potential for scale-up of the reaction has also been explored. The Royal Society of Chemistry.
- Kormos, Chad M.,Leadbeater, Nicholas E.
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- Alkoxycarbonylation reactions performed using near-stoichiometric quantities of CO
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Alkoxycarbonylation reactions using near-stoichiometric quantities of carbon monoxide gas are presented. The reactions are performed using microwave heating which, as well as the inherent advantages of rate acceleration, offers a convenient method for loading vessels with gases. Georg Thieme Verlag Stuttgart.
- Kormos, Chad M.,Leadbeater, Nicholas E.
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p. 2006 - 2010
(2008/02/09)
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