- Mechanistic insight into the synergistic Cu/Pd-catalyzed carbonylation of aryl iodides using alcohols and dioxygen as the carbonyl source
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Pd-catalyzed carbonylation, as an efficient synthetic approach to the installation of carbonyl groups in organic compounds, has been one of the most important research fields in the past decade. Although elegant reactions that allow highly selective carbonylations have been developed, straightforward routes with improved reaction activity and broader substrate scope remain long-term challenges for new practical applications. Here, we show a new type of synergistic Cu/Pd-catalyzed carbonylation reaction using alcohols and dioxgen as the carbonyl sources. A broad range of aryl iodides and alcohols are compatible with this protocol. The reaction is concise and practical due to the ready availability of the starting materials and the scalability of the reaction. In addition, the reaction affords lactones and lactams in an intermolecular fashion. Moreover, DFT calculations have been performed to study the detailed mechanisms. [Figure not available: see fulltext.]
- Li, Junxuan,Zhou, Jinlei,Wang, Yumei,Yu, Yue,Liu, Qiang,Yang, Tilong,Chen, Huoji,Cao, Hua
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- A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
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Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft"copper(I) hydrides to previously unreactive "hard"ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.
- Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
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supporting information
p. 16865 - 16873
(2021/10/20)
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- Using m icrowave and ultrasound to synthesis of substituted bis-acyl hydrazone derivatives
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In this paper, some new bis-acyl hydrazone derivatives (4a-f) were prepared through the reaction of carboxylic acid hydrazides with 1,4-diacetylbenzene using classical methods, microwave and ultrasound irradiation methods. These compounds are obtained through a series of reactions where some carboxylic acids react with ethanol first in the presence of concentrated sulfuric acid to give the corresponding esters (2a-f), which when treatment with aqueous hydrazine give carboxylic acid hydrazides (3a-f).thus, The results proved that the use of microwave and ultrasound techniques is much better than the classical methods, as it gave a higher yield, shorter reaction time, and the absence of the use of solvents. All newly synthesized compounds were confirmed by IR, (1H & 13C) NMR spectral analysis and the corresponding reactions were monitored by TLC using the reported eluent.
- Mohammed, Salim J.,Sheat, Attallah M.,A.abood, Salih,Yahya, Omar M.
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p. 6423 - 6427
(2021/11/01)
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- Design and synthesis of pyrimidine-5-carbonitrile hybrids as COX-2 inhibitors: Anti-inflammatory activity, ulcerogenic liability, histopathological and docking studies
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Two new series of 1,3,4-oxadiazole and coumarin derivatives based on pyrimidine-5-carbonitrile scaffold have been synthesized and evaluated for their COX-1/COX-2 inhibitory activity. Compounds 10c, 10e, 10h-j, 14e-f, 14i and 16 were found to be the most potent and selective inhibitors of COX-2 (IC50 0.041–0.081 μM, SI 139.74–321.95). Eight compounds were further investigated for their in vivo anti-inflammatory activity. The most active derivatives 10c, 10j and 14e displayed superior in vivo anti-inflammatory activity (% edema inhibition 39.3–48.3, 1 h; 58.4–60.5, 2 h; 70.8–83.2, 3 h; 78.9–89.5, 4 h) to the reference drug celecoxib (% edema inhibition 38.0, 1 h; 48.8, 2 h; 58.4, 3 h; 65.4, 4 h). These derivatives were also tested for their ulcerogenic liability, compound 10j showed better safety profile with reference to celecoxib while 10c and 14e exhibited mild lesions. Molecular docking studies of 10c, 10j, and 14e in the COX-2 active site revealed similar orientation and binding interactions as selective COX-2 inhibitors with a higher liability to access the selectivity side pocket.
- Alfayomy, Abdallah M.,Abdel-Aziz, Salah A.,Marzouk, Adel A.,Shaykoon, Montaser Sh. A.,Narumi, Atsushi,Konno, Hiroyuki,Abou-Seri, Sahar M.,Ragab, Fatma A.F.
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- Unravelling the anticancer potency of 1,2,4-triazole-N-arylamide hybrids through inhibition of STAT3: synthesis and in silico mechanistic studies
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Abstract: The discovery of potent STAT3 inhibitors has gained noteworthy impetus in the last decade. In line with this trend, considering the proven biological importance of 1,2,4-triazoles, herein, we are reporting the design, synthesis, pharmacokinetic profiles, and in vitro anticancer activity of novel C3-linked 1,2,4-triazole-N-arylamide hybrids and their in silico proposed mechanism of action via inhibition of STAT3. The 1,2,4-triazole scaffold was selected as a privilege ring system that is embedded in core structures of a variety of anticancer drugs which are either in clinical use or still under clinical trials. The designed 1,2,4-triazole derivatives were synthesized by linking the triazole-thione moiety through amide hydrophilic linkers with diverse lipophilic fragments. In silico study to predict cytotoxicity of the new hybrids against different kinds of human cancer cell lines as well as the non-tumor cells was conducted. The multidrug-resistant human breast adenocarcinoma cells (MDA-MB-231) was found most susceptible to the cytotoxic effect of synthesized compounds and hence were selected to evaluate the in vitro anticancer activity. Four of the designed derivatives showed promising cytotoxicity effects against selected cancer cells, among which compound 12 showed the highest potency (IC50 = 3.61?μM), followed by 21 which displayed IC50 value of 3.93?μM. Also, compounds 14 and 23 revealed equipotent activity with the reference cytotoxic agent doxorubicin. To reinforce these observations, the obtained data of in vitro cytotoxicity have been validated in terms of ligand–protein interaction and new compounds were analyzed for ADMET properties to evaluate their potential to build up as good drug candidates. This study led us to identify two novel C3-linked 1,2,4-triazole-N-arylamide hybrids of interesting antiproliferative potentials as probable lead inhibitors of STAT3 with promising pharmacokinetic profiles. Graphic abstract: [Figure not available: see fulltext.]
- Turky, Abdallah,Bayoumi, Ashraf H.,Sherbiny, Farag F.,El-Adl, Khaled,Abulkhair, Hamada S.
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p. 403 - 420
(2020/08/25)
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- Design, synthesis, in vitro and in vivo evaluation against MRSA and molecular docking studies of novel pleuromutilin derivatives bearing 1, 3, 4-oxadiazole linker
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A class of pleuromutilin derivatives containing 1, 3, 4-oxadiazole were designed and synthesized as potential antibacterial agents against Methicillin-resistant staphylococcus aureus (MRSA). The ultrasound-assisted reaction was proposed as a green chemistry method to synthesize 1, 3, 4-oxadiazole derivatives (intermediates 85–110). Among these pleuromutilin derivatives, compound 133 was found to be the strongest antibacterial derivative against MRSA (MIC = 0.125 μg/mL). Furthermore, the result of the time-kill curves displayed that compound 133 could inhibit the growth of MRSA in vitro quickly (- 4.36 log10 CFU/mL reduction). Then, compound 133 (- 1.82 log10 CFU/mL) displayed superior in vivo antibacterial efficacy than tiamulin (- 0.82 log10 CFU/mL) in reducing MRSA load in mice thigh model. Besides, compound 133 exhibited low cytotoxicity to RAW 264.7 cells. Molecular docking studies revealed that compound 133 was successfully localized in the binding pocket of 50S ribosomal subunit (ΔGb = -10.50 kcal/mol). The results indicated that these pleuromutilin derivatives containing 1, 3, 4-oxadiazole might be further developed into novel antibiotics against MRSA.
- Liu, Jie,Zhang, Guang-Yu,Zhang, Zhe,Li, Bo,Chai, Fei,Wang, Qi,Zhou, Zi-Dan,Xu, Ling-Ling,Wang, Shou-Kai,Jin, Zhen,Tang, You-Zhi
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- Design and synthesis of novel furan, furo[2,3-d]pyrimidine and furo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives as potential VEGFR-2 inhibitors
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Novel furan 6a-c, furo[2,3-d]pyrimidine 7a-f, 9, 10a-f, 12a,b, 14a-d and furo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine 8a-f derivatives were designed based on their structural similarity to a previously described oxazole VEGFR-2 back pocket binding fragment. The designed compounds were synthesized and screened for their in vitro VEGFR-2 inhibitory activity where they exhibited good to moderate nanomolar inhibition with improved ligand efficiencies. 8b and 10c (IC50 = 38.72 ± 1.7 and 41.40 ± 1.8 nM, respectively) were equipotent to sorafenib and 6a, 6c, 7f, 8a, 8c, 10b, 10f, 12b, 14c and 14d showed good activity (IC50 = 43.31–98.31 nM). The furotriazolopyrimidines 8a-c and furopyrimidine derivative 10c were further evaluated for their in vitro antiproliferative activity against human umbilical vein endothelial cells (HUVECs) where 8b showed higher potency than sorafenib and resulted in cell cycle arrest at G2/M phase whereas 8c revealed good antiproliferative activity with cell cycle arrest at G1 phase. Moreover, 8a-c and 10c showed significant inhibitory effects on the invasion and migration of HUVECs. Molecular docking study was conducted to gain insight about the potential binding mode. The furo[3,2-e][1,2,4]triazolo[1,5-c]pyrimidine derivatives 8b and 8c represent interesting starting point for antiangiogenic compounds based on their activity and favorable drug likeness profiles.
- Abd El-Mageed, Menna M.A.,Eissa, Amal A.M.,Farag, Awatef El-Said,Osman, Essam Eldin A.
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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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- Synthesis, molecular docking and evaluation of library of 3-mercapto-1,2,4-triazole derivatives as antimicrobial agents
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Due to the increasing microbial resistance to antibacterial and antifungal drugs, the development of new antimicrobial agents is an urgent priority. In search of newer antimicrobial agents, a series of 4,5-disubstituted-3-mercapto-1,2,4-triazole derivatives were synthesized from aromatic acids and substituted isothiocyanates. The in silico study was performed to study the binding interactions of the synthesized compounds with the active pocket of CYP51. Among the synthesized 3-mercapto-triazole derivatives, compounds 6r, 6s and 6u exhibited promising antimicrobial activity comparable to standard drugs. The results suggested that the structural modification to 3-mercapto-1,2,4-triazole derivatives could lead to promising antimicrobial scaffolds.
- Gaonkar, Santosh L.,Hakkimane, Sushruta S.,Nayak, Swarnagowri,Shetty, Nitinkumar S.,Swapna, B.
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p. 3039 - 3046
(2021/12/14)
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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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- Exploiting the photocatalytic activity of TiO2towards the depolymerization of Kraft lignin
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Lignin is a promising renewable source of aromatic chemicals. Described herein is a new photocatalytic methodology for depolymerization of oxidized Kraft lignin to industrially relevant aromatic platform chemicals. The photooxidation route begins with oxidation of alcohol moieties using a gold nanoparticle/hydrotalcite composite. Next, the oxidized lignin is subjected to UVA irradiation in the presence of TiO2, leading to a 3-fold decrease of its molecular weight and to the formation of various monolignols. The products obtained in both steps were characterized using FTIR, SEC, GC-MS, and 2D NMR spectroscopy, which confirm the depolymerization of lignin to smaller molecular weight products. This method offers both energetic and chemical advantages over thermochemical processing for lignin valorisation.
- Baker, R. Tom,Crites, Charles-Oneil L.,Gomes de Mendon?a, Fernanda,Hallett-Tapley, Geniece L.,Netto-Ferreira, José Carlos,Tremblay, Luc
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supporting information
p. 15371 - 15377
(2021/09/07)
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- Alternative method for the synthesis of triazenes from aryl diazonium salts
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An alternative mild method for access to 1-aryl-3,3-dimethyl alkyl triazenes is described. This protocol employs the dropwise addition of a methanolic solution of a carboxylate (RCO2M) or carbonate (CO32?) to a gently heated DMF solution containing an aryl diazonium salt (ArN2+), that had been previously isolated. Presumably homolysis of the weak N–O bond of diazo ether adducts formed in this operation initiates radical pathways that lead to the generation of triazene product. DMF serves as not only a one-electron donor to the diazonium salts employed in this process, but also as a source of dimethylamine radicals that act as a nucleophilic coupling partner. The reaction provides modest yields (ca. 20–40%) across an array of aryl diazonium salts that contain various substitution. Furthermore this unique approach to triazenes contrasts with traditional methods that employ dimethyl amine in reagent form which directly couples with diazonium salts. Seemingly, only one other example employing somewhat similar reaction conditions to this current investigation en route to triazenes has been reported, albeit with lower yields and for one representative example furnished as a side-product. The current work here improves upon the efficiency of this reported result, and further expands the reaction scope.
- Abrams
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- Electro-Oxidative Selective Esterification of Methylarenes and Benzaldehydes
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A mild and green electro-oxidative protocol to construct aromatic esters from methylarenes and alcohols is herein reported. Importantly, the reaction is free of metals, chemical oxidants, bases, acids, and operates at room temperature. Moreover, the design of the electrolyte was found critical for the oxidation state and structure of the coupling products, a rarely documented effect. This electro-oxidative coupling process also displays exceptional tolerance of many fragile easily oxidized functional groups such as hydroxy, aldehyde, olefin, alkyne, as well as neighboring benzylic positions. The enantiomeric enrichment of some chiral alcohols is moreover preserved during this electro-oxidative coupling reaction, making it overall a promising synthetic tool.
- Yu, Congjun,?zkaya, Bünyamin,Patureau, Frederic W.
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supporting information
p. 3682 - 3687
(2021/02/01)
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- Copper-mediated simple and direct aerobic oxidative esterification of arylacetonitriles with alcohols/phenols
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A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C-H bond, cleavage of inert C-C bond, and formation of C-O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
- Dong, Jianyu,Chen, Xiuling,Ji, Fangyan,Liu, Lixin,Su, Lebin,Mo, Min,Tang, Jian-Sheng,Zhou, Yongbo
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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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- Design, Synthesis, and Study of the Insecticidal Activity of Novel Steroidal 1,3,4-Oxadiazoles
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A series of novel steroidal derivatives with a substituted 1,3,4-oxadiazole structure was designed and synthesized, and the target compounds were evaluated for their insecticidal activity against five aphid species. Most of the tested compounds exhibited potent insecticidal activity against Eriosoma lanigerum (Hausmann), Myzus persicae, and Aphis citricola. Compounds 20g and 24g displayed the highest activity against E. lanigerum, showing LC50 values of 27.6 and 30.4 μg/mL, respectively. Ultrastructural changes in the midgut cells of E. lanigerum were detected by transmission electron microscopy, indicating that these steroidal oxazole derivatives might exert their insecticidal activity by destroying the mitochondria and nuclear membranes in insect midgut cells. Furthermore, a field trial showed that compound 20g exhibited effects similar to those of the positive controls chlorpyrifos and thiamethoxam against E. lanigerum, reaching a control rate of 89.5% at a dose of 200 μg/mL after 21 days. We also investigated the hydrolysis and metabolism of the target compounds in E. lanigerum by assaying the activities of three insecticide-detoxifying enzymes. Compound 20g at 50 μg/mL exhibited inhibitory action on carboxylesterase similar to the known inhibitor triphenyl phosphate. The above results demonstrate the potential of these steroidal oxazole derivatives to be developed as novel pesticides.
- Bai, Hangyu,Jiang, Weiqi,Li, Qi,Li, Tian,Ma, Shichuang,Shi, Baojun,Wu, Wenjun
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p. 11572 - 11581
(2021/10/12)
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- Pleuromutilin derivative with 1, 3, 4-oxadiazole side chain and preparation and application thereof
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The invention belongs to the field of medicinal chemistry, and particularly relates to a pleuromutilin derivative with a 1, 3, 4-oxadiazole side chain and preparation and application thereof The pleuromutilin derivative with the 1, 3, 4-oxadiazole side chain is a compound shown in a formula 2 or a pharmaceutically acceptable salt thereof, and a solvent compound, an enantiomer, a diastereoisomer and a tautomer of the compound shown in the formula 2 or the pharmaceutically acceptable salt thereof or a mixture of the solvent compound, the enantiomer, the diastereoisomer and the tautomer in any proportion, including a racemic mixture. The pleuromutilin derivative has good antibacterial activity, is especially suitable for being used as a novel antibacterial agent for systemic system infection of animals or human beings, and has good water solubility.
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Paragraph 0055-0056; 0070; 0090; 0092; 0095; 0103
(2021/07/24)
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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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- Metal-Free Oxidative Esterification of Ketones and Potassium Xanthates: Selective Synthesis of α-Ketoesters and Esters
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A novel and efficient oxidative esterification for the selective synthesis of α-ketoesters and esters has been developed under metal-free conditions. In the protocol, various α-ketoesters and esters are available in high yields from commercially available ketones and potassium xanthates. Mechanistic studies have proven that potassium xanthate not only promotes oxidative esterification but also provides an alkoxy moiety for the reaction, which involves the cleavage and reconstruction of C-O bonds.
- Luo, Xianglin,He, Runfa,Liu, Qiang,Gao, Yanping,Li, Jingqing,Chen, Xiuwen,Zhu, Zhongzhi,Huang, Yubing,Li, Yibiao
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p. 5220 - 5230
(2020/05/18)
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- HIGHLY POTENT TACC3 INHIBITOR AS A NOVEL ANTICANCER DRUG CANDIDATE
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The present invention relates to a new inhibitor chemotype 3-(4-methoxyphenyl)-N-(2-morpholinopyrimidin-4-yl) isoxazol-5-amine (BO-264) targeting TACC3 protein with high potency as a mitotic blocker for the treatment of breast and potentially other cancers.
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Page/Page column 12
(2020/02/14)
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- Design, synthesis and biological evaluation of N-hydroxy-aminobenzyloxyarylamide analogues as novel selective κ opioid receptor antagonists
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Aminobenzyloxyarylamide derivatives 1a-i and 2a-t were designed and synthesized as novel selective κ opioid receptor (KOR) antagonists. The benzoyl amide moiety of LY2456302 was changed into N-hydroxybenzamide and benzisoxazole-3(2H)-one to investigate whether it could increase the binding affinity or selectivity for KOR. All target compounds were evaluated in radioligand binding assays for opioid receptor binding affinity. These efforts led to the identification of compound 1c (κ Ki = 179.9 nM), which exhibited high affinity for KOR. Moreover, the selectivity of KOR over MOR and DOR increased nearly 2-fold and 7-fold, respectively, compared with (±)LY2456302.
- He, Guangchao,Peng, Kewen,Song, Qiao,Wang, Junwei,Xu, Anhua,Xu, Yungen,Zhu, Qihua
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- Synthesis of novel xanthene based analogues: Their optical properties, jack bean urease inhibition and molecular modelling studies
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In this work, a series of the rhodamine 6G based derivatives 5a-5g, were synthesized. The structural framework of the synthesized compounds was established by using 1H NMR, 13C NMR, FT-IR, and LC-MS analytical methods. The spectroscopic properties of the target compounds were determined by using absorption and fluorescence study in four different solvents. Furthermore, the synthesized derivatives were assessed for in-vitro screening against jack bean urease inhibition and in-silico molecular docking study. The result reveals that all the compounds exhibit good urease inhibitory activity against this enzyme but among the series, the compound 5a & 5c with an IC50 values of 0.1108 ± 0.0038 μM and 0.1136 ± 0.0295 μM shows to be most auspicious inhibitory activity compared to a standard drug (Thiourea) having IC50 value 4.7201 ± 0.0546 μM. Subsequently, the molecular docking experiment was analysed to distinguish the enzyme-inhibitor binding interaction.
- Dige, Nilam C.,Hassan, Mubashir,Lee, Ki Hwan,Mahajan, Prasad G.,Raza, Hussain,Seo, Sung-Yum,Vanjare, Balasaheb D.
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- Dual aminoquinolate diarylboron and nickel catalysed metallaphotoredox platform for carbon-oxygen bond construction
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Herein, aminoquinolate diarylboron complexes are utilized as photocatalysts in dual Ni/photoredox catalyzed carbon-oxygen construction reactions. Via this unified metallaphotoredox platform, diverse (hetero)aryl halides can be conveniently coupled with acids, alcohols and water. This method features operational simplicity, broad substrate scope and good compatibility with functional groups. This journal is
- Day, Craig,Jia, Xin,Wei, Lanfeng,Xu, Liang,Zu, Weisai
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supporting information
p. 8273 - 8276
(2020/08/17)
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- Metal-free and solvent-free synthesis of: M -terphenyls through tandem cyclocondensation of aryl methyl ketones with triethyl orthoformate
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Reported here is a novel cyclocondensation of aryl methyl ketones and triethyl orthoformate for the simple synthesis of m-terphenyls. In the presence of a catalytic amount of TfOH, alkyl- and chloro-substituted acetophenones produced a series of terphenyls through a tandem reaction which merged six steps into a one-pot procedure. Moreover, the corresponding ester products were obtained when using other substituted acetophenones as the starting materials under the same reaction conditions.
- Gan, Zongjie,Jiang, Wengao,Luo, Juan,Tang, Qiang,Xiao, Xiaoqin
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p. 12113 - 12118
(2020/04/10)
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- Nickel-Catalyzed Esterification of Amides Under Mild Conditions
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Abstract: The use of ligands to adjust the catalytic activity of the catalyst for esterification of amides is challenge in organic chemistry. In this paper, Nickel(II)-NHC-catalyzed the esterification reaction between N,N-di-Boc amide and alcohols at room temperature have been demonstrated. The imidazolium salt bearing a hydroxyl functionalized side arm showed high effective catalytic activity in the activation of the amide N–C bond in air atmosphere. Graphic Abstract: [Figure not available: see fulltext.].
- Li, Jun-Fei,Wang, Yao-Fang,Wu, Yuan-Yuan,Liu, Wen-Jing,Wang, Jun-Wen
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p. 874 - 880
(2019/11/13)
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- Oxidative Esterification of Aldehydes and Alcohols Catalyzed by Camphor-Based Imidazolium Salts
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Abstract: Sixteen new camphor-based imidazolium salts have been synthesized with renewable camphorsulfonic acid as the starting material. The chemical shifts of the characteristic proton of C2 on the imidazolium ring (N?C=N) were discussed thoroughly and all of these imidazolium salts exhibit good thermal stability. Furthermore, the excellent catalytic performance of the synthesized imidazolium salts were observed in the oxidative esterification between aromatic or aliphatic aldehydes containing electron-withdrawing or electron-donating groups on aromatic ring and primary or secondary alcohol by air as the sole oxidant. Graphic Abstract: [Figure not available: see fulltext.].
- Bian, Tiancen,Feng, Li,Li, Danfeng,Huang, Jiaxin,Zhao, Yuxun,Xu, Xu,Yang, Yiqin,Wang, Shifa
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p. 1812 - 1820
(2020/01/11)
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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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- Design, synthesis and molecular docking of new N-4-piperazinyl ciprofloxacin-triazole hybrids with potential antimicrobial activity
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New N-4-piperazinyl ciprofloxacin-triazole hybrids 6a-o were prepared and characterized. The in vitro antimycobacterial activity revealed that compound 6a experienced promising antimycobacterial activity against Mycobactrium smegmatis compared with the reference isoniazide (INH). Additionally, compound 6a exhibited broad spectrum antibacterial activity against all the tested strains either Gram-positive or Gram-negative bacteria compared with the reference ciprofloxacin. Also, compounds 6g and 6i displayed considerable antifungal activity compared with the reference ketoconazole. DNA cleavage assay of the highly active compounds 6c and 6h showed a good correlation between the Mycobactrium cleaved DNA gyrase assay and their in vitro antimycobactrial activity. Moreover, molecular modeling studies were done for the designed ciprofloxacin derivatives to predict their binding modes towards Topoisomerase II enzyme (PDB: 5bs8).
- Mohammed, Hamada H.H.,Abdelhafez, El-Shimaa M.N.,Abbas, Samar H.,Moustafa, Gamal A.I.,Hauk, Glenn,Berger, James M.,Mitarai, Satoshi,Arai, Masayoshi,Abd El-Baky, Rehab M.,Abuo-Rahma, Gamal El-Din A.
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- Synthesis and biological evaluation of novel disulfides incorporating 1,3,4-thiadiazole scaffold as promising antitumor agents
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In the present study, fourteen 2,5-disubstituted 1,3,4-thiadiazole derivatives containing disulfide group were prepared. The resulting compounds 7a–7n were identified by IR, NMR, MS, and elemental analysis. Their antiproliferative properties in vitro were studied employing standard CCK-8 assay against SMMC-7721, MCF-7, and A549 lines. Bioassay indicated that some compounds showed stronger antitumor effects than reference drugs PX-12 and 5-fluorouracil. Among these screened compounds, compound 7h showed excellent biological activities in inhibiting SMMC-7721 cell proliferation with IC50 at 1.93 ± 0.08 μM. Compounds 7k and 7i manifested highly effective growth inhibitory activity versus MCF-7 cells, with IC50 at 3.04 ± 0.09 and 3.54 ± 0.17 μM, respectively. For A549 cells, compound 7m was found to have the highest antitumor potency with IC50 at 3.67 ± 0.13 μM.
- Li, Sha,Wang, Hai-Xin,Liu, Hai-Ying,Jing, Fen,Fu, Xiao-Yun,Li, Cai-Wen,Shi, Yan-Ping,Chen, Bao-Quan
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p. 1502 - 1508
(2019/07/30)
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- Synthesis, molecular docking, antimicrobial evaluation, and DNA cleavage assay of new thiadiazole/oxadiazole ciprofloxacin derivatives
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Abstract: Herein we report the synthesis of new N-4-piperazinyl thiadiazole and oxadiazole ciprofloxacin derivatives and their antibacterial and antimycobacterial activities. Although thiadiazole ciprofloxacin derivatives compound showed broad spectrum antibacterial activity against all the tested strains either Gram-positive or Gram-negative organisms, the oxadiazole derivatives exhibited weaker antibacterial and antimycobacterial activities than thiadiazole derivatives against most of the tested strains compared with the reference ciprofloxacin. Moreover, the antimycobacterial screening revealed that compounds which containing thiadiazole scaffold potently inhibited Mycobacterium smegmatis at MIC of 1.56 and 3.13, respectively, and modestly inhibited the drug-resistant strains. DNA cleavage assay revealed that thiadiazole ciprofloxacin derivatives inhibited supercoil relaxation, albeit to a lesser extent than ciprofloxacin, and it also increased the amount of nicked substrate produced. Graphic abstract: [Figure not available: see fulltext.].
- Mohammed, Hamada H. H.,Abbas, Samar H.,Abdelhafez, El-Shimaa M. N.,Berger, James M.,Mitarai, Satoshi,Arai, Masayoshi,Abuo-Rahma, Gamal El-Din A. A.
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p. 1809 - 1824
(2019/11/05)
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- Targeting malaria and leishmaniasis: Synthesis and pharmacological evaluation of novel pyrazole-1,3,4-oxadiazole hybrids. Part II
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In continuance with earlier reported work, an extension has been carried out by the same research group. Mulling over the ongoing condition of resistance to existing antimalarial agents, we had reported synthesis and antimalarial activity of certain pyrazole-1,3,4-oxadiazole hybrid compounds. Bearing previous results in mind, our research group ideated to design and synthesize some more derivatives with varied substitutions of acetophenone and hydrazide. Following this, derivatives 5a–r were synthesized and tested for antimalarial efficacy by schizont maturation inhibition assay. Further, depending on the literature support and results of our previous series, certain potent compounds (5f, 5n and 5r) were subjected to Falcipain-2 inhibitory assay. Results obtained for these particular compounds further strengthened our hypothesis. Here, in this series, compound 5f having unsubstituted acetophenone part and a furan moiety linked to oxadiazole ring emerged as the most potent compound and results were found to be comparable to that of the most potent compound (indole bearing) of previous series. Additionally, depending on the available literature, compounds (5a–r) were tested for their antileishmanial potential. Compounds 5a, 5c and 5r demonstrated dose-dependent killing of the promastigotes. Their IC50 values were found to be 33.3 ± 1.68, 40.1 ± 1.0 and 19.0 ± 1.47 μg/mL respectively. These compounds (5a, 5c and 5r) also had effects on amastigote infectivity with IC50 of 44.2 ± 2.72, 66.8 ± 2.05 and 73.1 ± 1.69 μg/mL respectively. Further target validation was done using molecular docking studies. Acute oral toxicity studies for most active compounds were also performed.
- Verma, Garima,Khan, Mohemmed Faraz,Mohan Nainwal, Lalit,Ishaq, Mohd,Akhter, Mymoona,Bakht, Afroz,Anwer, Tariq,Afrin, Farhat,Islamuddin, Mohammad,Husain, Ibraheem,Alam, Mohammad Mumtaz,Shaquiquzzaman, Mohammad
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- Synthesis, characterization and assessment of local anesthetic activity of some benzohydroxamic acids
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In the present investigation, 6 compounds (E1-E6) were synthesized by reaction of ethyl esters of p-substituted benzoic acid with hydroxylamine. The chemical structures of the synthesized hydroxamic acids were verified on the basis of spectral analysis (IR, 1H NMR, 13C NMR and mass spectra). The benzohydroxamic acids were examined for potential local anesthetic activity using foot withdrawal reflex of the frog and benzocaine was used as standard drug. Compounds were tested at two different solvents; 5 % DMSO and 0.65 % NaOH, each solution was tested at three different concentration levels (40, 100 and 200 μg/mL). Local anesthetic activity of the compounds differed according to the concentration level and selected solvent. Compounds E4 and E5 were found to be the most active and were comparable to the standard drug in tested solvents at all investigated concentrations. All compounds displayed an enhanced activity in the the aqueous basic solutions.
- Aldeen, Ekhlas Sheakh,Elsaman, Tilal,Mohamed, Malik Suliman,Adam, Mohamed E.,Mohamed, Magdi Awadalla
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p. 181 - 185
(2018/12/11)
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- 1,3,4-oxadiazole/chalcone hybrids: Design, synthesis, and inhibition of leukemia cell growth and EGFR, Src, IL-6 and STAT3 activities
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A new series of 1,3,4-oxadiazole/chalcone hybrids was designed, synthesized, identified with different spectroscopic techniques and biologically evaluated as inhibitors of EGFR, Src, and IL-6. The synthesized compounds showed promising anticancer activity, particularly against leukemia, with 8v being the most potent. The synthesized compounds exhibited strong to moderate cytotoxic activities against K-562, KG-1a, and Jurkat leukemia cell lines in MTT assays. Compound 8v showed the strongest cytotoxic activity with IC50 of 1.95 μM, 2.36 μM and 3.45 μM against K-562, Jurkat and KG-1a leukemia cell lines, respectively. Moreover; the synthesized compounds inhibited EGFR, Src, and IL-6. Compound 8v was most effective at inhibiting EGFR (IC50 = 0.24 μM), Src (IC50 = 0.96 μM), and IL-6 (% of control = 20%). Additionally, most of the compounds decreased STAT3 activation.
- Fathi, Marwa Ali A.,Abd El-Hafeez, Amer Ali,Abdelhamid, Dalia,Abbas, Samar H.,Montano, Monica M.,Abdel-Aziz, Mohamed
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p. 150 - 163
(2018/12/11)
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- Synthesis and anticancer evaluation of new lipophilic 1,2,4 and 1,3,4-oxadiazoles
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A series of1,2,4- and 1,3,4-oxadiazole derivatives were synthesized and evaluated for their anticancer activity. Halogenated 1,2,4-oxadiazoles were obtained from benzonitrile and coupled either lipophilic amines or with aminoalcohols. Lipophilic 1,3,4-oxadiazole derivatives were obtained through the Mannich reactions between 5-(aryl)-1,3,4-oxadiazole-2-thiol and alkylated or acylated amines. The in vitro cytotoxic effects were evaluated against 4T1– mammary carcinoma and CT26 – colon cancer cells. The best results were obtained for the 1,3,4-oxadiazole coupled to alkylated piperazine with 10–14 carbon chain moiety, with IC50 values ranging from 1.6 to 3.55μΜ for the 4T1 cell line, and from 1.6 to 3.9 μM for the CT26.WT cell line, and selectivity index up to 19. The most potent compounds were investigated with AnnexinV and PI staining as indicative of apoptosis induction.
- Caneschi, Wiliam,Enes, Karine Braga,Carvalho de Mendon?a, Camille,de Souza Fernandes, Fábio,Miguel, Fabio Balbino,da Silva Martins, Jefferson,Le Hyaric, Mireille,Pinho, Roberto Rosas,Duarte, Lucas Mattos,Leal de Oliveira, Marcone Augusto,Dos Santos, Hélio F.,Paz Lopes, Miriam Teresa,Dittz, Dalton,Silva, Heveline,Costa Couri, Mara Rubia
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- Symmetrical heterocyclic cage skeleton: Synthesis, urease inhibition activity, kinetic mechanistic insight, and molecular docking analyses
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The present study focuses on the design and synthesis of a cage-like organic skeleton containing two triazole rings jointed via imine linkage. These molecules can act as urease inhibitors. The in-vitro urease inhibition screening results showed that the combination of the two triazole skeleton in the cage-like morphology exhibited comparable urease inhibition activity to that of the reference thiourea while the metallic complexation, especially with copper, nickel, and palladium, showed excellent activity results with IC50 values of 0.94 ± 0.13, 3.71 ± 0.61, and 7.64 ± 1.21 (3a–c), and 1.20 ± 0.52, 3.93 ± 0.45, and 12.87 ± 2.11 μM (4a–c). However, the rest of compounds among the targeted series exhibited a low to moderate enzyme inhibition potential. To better understand the compounds’ underlying mechanisms of the inhibitory effect (3a and 4a) and their most active metal complexes (3b and 4b), we performed an enzymatic kinetic analysis using the Lineweaver–Burk plot in the presence of different concentrations of inhibitors to represent the non-competitive inhibition nature of the compounds, 3a, 4a, and 4b, while mixed type inhibition was represented by the compound, 3b. Moreover, molecular docking confirmed the binding interactive behavior of 3a within the active site of the target protein.
- Hanif, Muhammad,Kanwal, Fariha,Rafiq, Muhammad,Hassan, Mubashir,Mustaqeem, Muhammad,Seo, Sung-Yum,Zhang, Yunlong,Lu, Changrui,Chen, Ting,Saleem, Muhammad
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supporting information
(2019/02/09)
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- Design, synthesis and biological evaluation of 2-(phenoxymethyl)-5-phenyl-1,3,4-oxadiazole derivatives as anti-breast cancer agents
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Structural based molecular docking approach revealed the findings of 2-(phenoxymethyl) -5-phenyl-1,3,4-oxadiazole derivatives. The compounds (7a-o) were synthesized and characterized well by using conventional methods. The compounds, 7b and 7m were reconfirmed through single crystal XRD analysis. The synthesized compounds (7a-o) were evaluated their antiproliferative activities against MCF-7 and MDA-MB-453. Furthermore, Lipinski's rule of five and pharmacokinetic properties were predicted for the test compounds. These results demonstrate that the compounds 7b and 7d exhibit more potent cytotoxicity and 7d exhibits dose-dependent activity and reduced cell viability. Further, the mechanism of action for the induced apoptosis was observed through morphological changes and western blotting analysis. These findings may furnish the lead for further development.
- Lakshmithendral,Saravanan,Elancheran,Archana,Manikandan,Arjun,Ramanathan,Lokanath,Kabilan
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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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- Practical heterogeneous photoredox/nickel dual catalysis for C-N and C-O coupling reactions
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Efficient C-N and C-O coupling reactions of aryl halides with amines and alcohols have been developed by using the strategy of heterogeneous visible light photoredox and nickel dual catalysis. Obviously, the joint use of inexpensive and bench-stable CdS and nickel salts, together with mild reaction conditions, makes these two transformations attractive for the synthetic community. This heterogeneous dual catalysis system also proved to be successful in the ligand-free catalytic hydroxylation of aryl bromide with water as a nucleophile. The practicality of this protocol is further emphasized by the scaled-up reaction and the reusability of heterogeneous photocatalysts.
- Liu, Yi-Yin,Liang, Dong,Lu, Liang-Qiu,Xiao, Wen-Jing
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supporting information
p. 4853 - 4856
(2019/05/02)
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- Dehydrogenative cross-coupling of primary alcohols to form cross-esters catalyzed by a manganese pincer complex
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Base-metal-catalyzed dehydrogenative cross-coupling of primary alcohols to form cross-esters as major products, liberating hydrogen gas, is reported. The reaction is catalyzed by a pincer complex of earth-abundant manganese in the presence of catalytic base, without any hydrogen acceptor or oxidant. Mechanistic insight indicates that a dearomatized complex is the actual catalyst, and indeed this independently prepared dearomatized complex catalyzes the reaction under neutral conditions.
- Das, Uttam Kumar,Ben-David, Yehoshoa,Leitus, Gregory,Diskin-Posner, Yael,Milstein, David
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p. 479 - 484
(2019/01/11)
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- Camphoryl imidazole type ionic liquid and preparation method and application thereof
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The invention discloses a camphoryl imidazole type ionic liquid and a preparation method and application thereof. According to the preparation method, a derivative camphorsulfonic acid of a natural renewable resource camphor is taken as a raw material to prepare 10-iodocamphor; then the 10-iodocamphor and aryl imidazole are subjected to a quaterisation reaction to prepare camphoryl imidazole iodide; then the camphoryl imidazole iodide and sodium hexafluorophosphate, sodium tetrafluoroborate, bis(trifluorosulfonimide)lithium and the like are subjected to ion exchange to prepare camphoryl imidazole hexafluorophosphate, camphoryl imidazole tetrafluoroborate, camphoryl imidazole bis(trifluorosulfonimide)salt and other ionic liquids. The camphoryl imidazole type ionic liquid shows good catalytic activity for an oxidation esterification reaction of aldehyde-alcohol, has the advantages of short reaction time, good reaction selectivity and high product yield, and has a good application prospect.
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Paragraph 0060; 0073
(2019/10/05)
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- Unprecedented alkylation of carboxylic acids by boron trifluoride etherate
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The alkylation of carboxylic acids by an ethyl moiety of boron trifluoride etherate in the absence of ethyl alcohol from the reaction system is unexpected and novel. Both aromatic and aliphatic carboxylic acids were clearly alkylated affording good yields in short reaction times with the exception of nicotinic acid that necessitated an overnight reaction. It was noted that while ortho-substituted hydroxyl groups of carboxylic acids investigated were not affected by alkylation, those of meta- and para-substituted carboxylic acids were partially etherified. Furthermore, the alkylation reaction was found to be compatible with a range of functional groups such as halogens, amino and nitro groups except for the alkene function of undecylenic acid that underwent polymerisation with concomitant alkylation of its carboxylic acid function.
- Jumbam, Ndze D.,Maganga, Yamkela,Masamba, Wayiza,Mbunye, Nomthandazo I.,Mgoqi, Esethu,Mtwa, Sphumusa
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p. 387 - 392
(2018/09/06)
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- Phosphite-catalyzed alkoxycarbonylation of aryl diazonium salts
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In this communication, an interesting phosphite-catalyzed alkoxycarbonylation of aryl diazonium salts has been reported. At room temperature and under CO pressure, moderate to good yields of the desired esters can be produced in the absence of bases or an
- Xu, Jian-Xing,Franke, Robert,Wu, Xiao-Feng
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supporting information
p. 6180 - 6182
(2018/09/10)
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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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- Porous organic cage stabilised palladium nanoparticles: Efficient heterogeneous catalysts for carbonylation reaction of aryl halides
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Porous organic cage stabilised palladium nanoparticles were successfully prepared using methanol as a mild reductant. The as-prepared porous composite materials show high catalytic activity for the carbonylation reaction of aryl halides under mild conditions.
- Zhang, Yong,Xiong, Yu,Ge, Jin,Lin, Rui,Chen, Chen,Peng, Qing,Wang, Dingsheng,Li, Yadong
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supporting information
p. 2796 - 2799
(2018/03/21)
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- Versatile Heterogeneous Palladium Catalysts for Diverse Carbonylation Reactions under Atmospheric Carbon Monoxide Pressure
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Herein, we report a versatile carbonylation protocol using heterogeneous Pd0 nanoparticles supported on the metal–organic frameworks (MOFs) MIL-88B-NH2 (Fe/Cr). The synthesis of a vast array of carbonyls, which includes amides, esters, carboxylic acids, and α-ketoamides, was achieved through mono- and dicarbonylation reactions. The selectivity could be controlled simply by tuning the reaction conditions. Superior activity and selectivity were recorded in some cases compared to that achieved with commercial Pd/C. However, the utility of an elaborate catalyst support is questionable and important reactivity and recyclability issues are discussed.
- Vico Solano, Marta,González Miera, Greco,Pascanu, Vlad,Inge, A. Ken,Martín-Matute, Belén
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p. 1089 - 1095
(2018/02/06)
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- Fe-catalyzed esterification of amides via C-N bond activation
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An efficient Fe-catalyzed esterification of primary, secondary, and tertiary amides with various alcohols for the preparation of esters was performed. The esterification process was accomplished with FeCl3$6H2O, which is a stable, inexpensive, environmentally friendly catalyst with high functional group tolerance.
- Chen, Xiuling,Hu, Siying,Chen, Rongxing,Wang, Jian,Wu, Minghu,Guo, Haibin,Sun, Shaofa
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p. 4571 - 4576
(2018/02/09)
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- Efficient synthesis of esters through oxone-catalyzed dehydrogenation of carboxylic acids and alcohols
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Since esters are important organic synthesis intermediates, an environmentally friendly oxone catalyzed-esterification of carboxylic acids with alcohols has been developed. A series of carboxylic acid esters are obtained in high yield. This strategy requires mild reaction conditions, providing an attractive alternative for the construction of valuable carbonyl esters. Electron-rich and electron-deficient groups are compatible with the standard conditions and a variety of substrates are demonstrated. Moreover, the reaction could easily be adapted to typical prodrugs, drugs and gram-scale synthesis.
- Hou, Fei,Wang, Xi-Cun,Quan, Zheng-Jun
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supporting information
p. 9472 - 9476
(2019/01/03)
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