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Further characterization of mitsunobu-type intermediates in the reaction of dialkyl azodicarboxylates with P(III) compounds
Structural characterization of compounds analogous to the proposed intermediates in the Mitsunobu esterification process is achieved by the combined use of NMR spectroscopy and X-ray diffractometric studies. The results show that compounds (t-BuNH)P(μ-N-t-Bu)2P[(N-t-Bu)(N-(CO 2R)-N(H)(CO2R))] [R = Et (11), i-Pr (12)], obtained by treating [(t-Bu-NH)P-μ-N-t-Bu]2 (10) with diethylazodicarboxylate (DEAD) or diisopropylazodicarboxylate (DIAD), respectively, have a structure with the NH proton residing between the two nitrogen atoms ((P)N(t-Bu) and (P)N-N(CO2Et)); this is the tautomeric form of the expected betaine (t-BuNH)P(μ-N-t-Bu)2P+[(NH-t-Bu)(N-(CO 2R)-N-(CO2R)]. Treatment of ClP(μ-N-t-Bu) 2P[(N-t-Bu){N-(CO2-i-Pr)-N(H)(CO2-i-Pr)] (6) with 2,6-dicholorophenol affords (2,6-Cl2-C6H 3-O)P-(μ-N-t-Bu)2P+[(NH-t-Bu){N[(CO 2i-Pr)(HNCO2i-Pr)]}](Cl-)(2,6-Cl 2-C6H3-OH) (14) that has a structure similar to that of (CF3CH2O)P(μ-N-t-Bu)2P +[(NH-t-Bu){N[(CO2i-Pr)(HNCO2i-Pr)]}](Cl -) (13), but with an additional hydrogen bonded phenol. Both of these have the protonated betaine structure analogous to that of Ph3P +N(CO2R)NH(CO2R)(R′CO2) - (2) proposed in the Mitsunobu esterification. Two other compounds, (ArO)P(μ-N-t-Bu)2P+(NH-t-Bu){N(CO2i-Pr) (HNCO2i-Pr)}(Cl-) [Ar = 2,6-Me2C 6H3O- (15) and 2-Me-6-t-Bu-C6H3-O- (16)], are also prepared by the same route. Although NMR tube reactions of 11 or 12 with tetrachlorocatechol, catechol, 2,2′-biphenol, and phenol revealed significant changes in the 31P NMR spectra, attempted isolation of these products was not successful. On the basis of 31P NMR spectra, the phosphonium salt structure (t-BuNH)P(μ-N-t-Bu)2P +[(HN-t-Bu){N-(CO2R)-N(H)(CO2R)]-(ArO -) is proposed for these. The weakly acidic propan-2-ol or water did not react with 11 or 12, Treatment of 12 with carboxylic acids/p-toluenesulfonic acid gave the products (t-BuNH)P(μ-N-t-Bu)2P+[(HN-t- Bu){N-(CO2-i-Pr)-N(H)(CO2-i-Pr)](ArCO2-) [Ar = Ph (18), 4-Cl-C6H4CH2 (19), 4-Br-C 6H4 (20), 4-NO2-C6H4 (21)] and (t-BuNH)P(μ-N-t-Bu)2P+|(HN-t-Bu){N-(CO 2-i-Pr)-N(H)(CO2-i-Pr)](4-CH3-C 6H4SO3-) (22) that have essentially the same structure as 2. Compound 18 has additional stabilization by hydrogen bonding, as revealed by X-ray structure determination. Finally it is shown that the in situ generated (t-BuNH)P(μ-N-t-Bu)2P+[(HN-t-Bu) {N-(CO2Et)-N(H)(CO2Et)](4-NO2-C 6H4CO2-) can also effect Mitsunobu esterification. A comparison of the Ph3P-DIAD system with the analogous synthetically useful Ph3P-dimethyl acetylenedicarboxylate (DMAD) system is made.
Kumara Swamy,Praveen Kumar,Bhuvan Kumar
p. 1002 - 1008
(2006)
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Synthesis, spectral analysis, antibacterial, antifungal, antioxidant and hemolytic activity studies of some new 2,5-disubstituted-1,3,4-oxadiazoles
Series of 1,3,4-oxadiazole derivatives (5a–5g and 5h, 5i) were synthesized and characterized by FT-IR, 1H NMR, 13C NMR and HR-MS spectral analysis. All the target compounds were screened for their in vitro antibacterial activity against two Gram-negative bacterial strains namely Escherichia coli (MTCC 405) and Salmonella typhi (MTCC 3224) and two Gram-positive bacterial strains namely Bacillus subtilis (MTCC 1790) and Bacillus megaterium (MTCC 1684) and antifungal activity against Aspergillus niger (MTCC 282), Rhizopus oryzae (MTCC 262), Penicillium chrysogenum (MTCC 974), and Candida albicans (MTCC 183) fungal strains. The synthesized compounds exhibited significant antibacterial and antifungal potential. Three compounds (5e, 5f and 5g) have shown higher antibacterial activity with very low MIC values comparable to streptomycin. According to the SAR study, the antibacterial efficacy can be intensified by substituting fluoro and methyl substituents at the para position in acid hydrazide. The synthesized compounds were also screened for % radical scavenging activity by OH and DPPH assay and found to be good antioxidant agents. Besides, the hemolytic study revealed that the synthesized 1,3,4-oxadiazoles possessed negligible cytotoxicity compared with the standard.
Adole, Vishnu A.,Chobe, Santosh S.,Dhonnar, Sunil L.,Jagdale, Bapu S.,More, Rahul A.,Sadgir, Nutan V.
(2022/01/04)

The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.
Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
supporting information
p. 5680 - 5686
(2021/08/16)

Selective Mild Oxidation of Anilines into Nitroarenes by Catalytic Activation of Mesoporous Frameworks Linked with Gold-Loaded Mn3O4 Nanoparticles
This work reports the synthesis and catalytic application of mesoporous Au-loaded Mn3O4 nanoparticle assemblies (MNAs) with different Au contents, i. e., 0.2, 0.5 and 1 wt %, towards the selective oxidation of anilines into the corresponding nitroarenes. Among common oxidants, as well as several supported gold nanoparticle platforms, Au/Mn3O4 MNAs containing 0.5 wt % Au with an average particle size of 3–4 nm show the best catalytic performance in the presence of tert-butyl hydroperoxide (TBHP) as a mild oxidant. In all cases, the corresponding nitroarenes were isolated in high to excellent yields (85–97 %) and selectivity (>98 %) from acetonitrile or greener solvents, such as ethyl acetate, after simple flash chromatography purification. The 0.5 % Au/Mn3O4 catalyst can be isolated and reused four times without a significant loss of its activity and can be applied successfully to a lab-scale reaction of p-toluidine (1 mmol) leading to the p-nitrotulene in 83 % yield. The presence of AuNPs on the Mn3O4 surface enhances the catalytic activity for the formation of the desired nitroarene. A reasonable mechanism was proposed including the plausible formation of two intermediates, the corresponding N-aryl hydroxylamine and the nitrosoarene.
Armatas, Gerasimos S.,Daikopoulou, Vassiliki,Koutsouroubi, Eirini D.,Lykakis, Ioannis N.,Skliri, Euaggelia
(2021/11/01)

Ni-NiO heterojunctions: a versatile nanocatalyst for regioselective halogenation and oxidative esterification of aromatics
Herein, we report a facile method for the synthesis of Ni-NiO heterojunction nanoparticles, which we utilized for the nuclear halogenation reaction of phenol and substituted phenols usingN-bromosuccinimide (NBS). A remarkablepara-selectivity was achieved for the halogenated products under semi-aqueous conditions. Interestingly, blocking of thepara-position of phenol offeredortho-selective halogenation. In addition, the Ni-NiO nanoparticles catalyzed the oxidative esterification of carbonyl compounds with alcohol, diol or dithiol in the presence of a catalytic amount of NBS. It was observed that the aromatic carbonyls substituted with an electron-donating group favoured nuclear halogenation, whereas an electron-withdrawing group substitution in carbonyl compounds facilitated the oxidation reaction. In addition, the catalyst was magnetically separated and recycled 10 times. The tuned electronic structure at the Ni-NiO heterojunction controlled selectivity and activity as no suchpara-selectivity was observed with commercially available NiO or Ni nanoparticles.
Bhardwaj, Nivedita,Goel, Bharat,Indra, Arindam,Jain, Shreyans K.,Singh, Ajit Kumar,Tripathi, Nancy
p. 14177 - 14183
(2021/08/16)

Vitamin B1-catalyzed aerobic oxidative esterification of aromatic aldehydes with alcohols
A straightforward aerobic oxidative esterification of aryl aldehydes with alcohols has been developed for the synthesis of substituted esters by employing vitamin B1 as a cost-effective, metal-free, and eco-friendly NHC catalyst. Air is used as a green terminal oxidant. The reaction is a useful addition to the existing NHC-catalytic oxidative esterification.
Chu, Xue-Qiang,Ge, Danhua,Luo, Xin-Long,Xu, Pei,Yu, Zi-Lun
supporting information
p. 30937 - 30942
(2021/11/19)

Design, Synthesis, and Study of the Insecticidal Activity of Novel Steroidal 1,3,4-Oxadiazoles
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
p. 11572 - 11581
(2021/10/12)

Sulfonated covalent triazine polymer loaded with Pd nanoparticles as a bifunctional catalyst for one pot hydrogenation esterification reaction
Highly dispersed Pd nanoparticles over covalent triazine polymer functionalized with sulfonic acid groups (CTP-SO3H/Pd) were prepared by facile Friedel-Crafts reaction, post synthetic sulfonation and Pd immobilization method. The prepared catalyst was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption, inductively coupled plasma - optical emission spectrometry (ICP-OES), elemental analysis and X-ray photoelectron spectroscopy (XPS). The sulfonic acid groups were grafted into the terphenyl backbone and the presence of triazine functionality within the framework enabled the uniform dispersion of palladium nanoparticles over the polymer network. When used as a bifunctional catalyst in one pot hydrogenation-esterification (OHE) reaction, the CTP-SO3H/Pd exhibited good activity and stability. The performance of CTP-SO3H/Pd is due to the surface-active acid/metal sites and was evident from the yield of the product in the reaction. The catalyst was easily recovered by filtration and recycle tests showed that it could be re-used for at least five repetitive runs with minor loss of catalytic activity suggesting its potential utility in OHE reaction. A plausible mechanistic pathway for OHE reaction over CTP-SO3H/Pd was also proposed.
Ravi, S.,Raza, A. Ahmed,Sheriff, A. K. Ibrahim,Tajudeen, S. Syed
(2021/07/17)

Using m icrowave and ultrasound to synthesis of substituted bis-acyl hydrazone derivatives
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.
p. 6423 - 6427
(2021/11/01)

Synthesis, characterization, and biological evaluation of new derivatives targeting MbtI as antitubercular agents
Tuberculosis (TB) causes millions of deaths every year, ranking as one of the most dangerous infectious diseases worldwide. Because several pathogenic strains of Mycobacterium tuberculosis (Mtb) have developed resistance against most of the established anti-TB drugs, new therapeutic options are urgently needed. An attractive target for the development of new antitubercular agents is the salicylate synthase MbtI, an essential enzyme for the mycobacterial siderophore biochemical machinery, absent in human cells. A set of analogues of I and II, two of the most potent MbtI inhibitors identified to date, was synthesized, characterized, and tested to elucidate the structural requirements for achieving an efficient MbtI inhibition and a potent antitubercular activity with this class of compounds. The structure-activity relationships (SAR) here discussed evidenced the importance of the furan as part of the pharmacophore and led to the preparation of six new compounds (IV-IX), which gave us the opportunity to examine a hitherto unexplored position of the phenyl ring. Among them emerged 5-(3-cyano-5-(trifluoromethyl)phenyl)furan-2-carboxylic acid (IV), endowed with comparable inhibitory properties to the previous leads, but a better antitubercular activity, which is a key issue in MbtI inhibitor research. Therefore, compound IV offers promising prospects for future studies on the development of novel agents against mycobacterial infections.
Mori, Matteo,Stelitano, Giovanni,Chiarelli, Laurent R.,Cazzaniga, Giulia,Gelain, Arianna,Barlocco, Daniela,Pini, Elena,Meneghetti, Fiorella,Villa, Stefania
p. 1 - 17
(2021/02/26)

Development of Novel (+)-Nootkatone Thioethers Containing 1,3,4-Oxadiazole/Thiadiazole Moieties as Insecticide Candidates against Three Species of Insect Pests
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
p. 15544 - 15553
(2022/01/03)

New quinoxaline-2(1H)-ones as potential VEGFR-2 inhibitors: design, synthesis, molecular docking, ADMET profile and anti-proliferative evaluations
Eleven new quinoxaline derivatives were designed and synthesized as modified VEGFR-2 inhibitors of our previous work. The synthesized compounds were tested against three human cancer cell lines (HepG-2, MCF-7 and HCT-116). Compounds11g,11eand11cwere the most potent members against the tested cells. Compound11g(IC50= 4.50, 2.40, and 5.90 μM) was the most potent member compared to doxorubicin (IC50= 8.29, 9.65, and 7.68 μM) and sorafenib (IC50= 7.33, 9.41, and 7.23 μM) against HepG-2 and HCT-116, and MCF-7 cell lines, respectively. Compound11eshowed better anti-proliferative activities than doxorubicin and sorafenib with IC50values of 5.34, 4.19, and 6.06 μM, against HepG-2 and HCT-116 and MCF-7 cell lines, respectively. In addition, the most active anti-proliferative derivatives11c,11e,11f, and11gwere selected to evaluate their inhibitory activities against VEGFR-2. The tested compounds displayed good inhibitory activity with IC50values ranging from 0.75 to 1.36 μM. Among them, compound11gwas the most active member with an IC50value of 0.75 μM, compared to the reference drug; sorafenib (IC50= 1.29 μM). Moreover, docking studies revealed that the synthesized compounds have good binding patterns against the prospective molecular target; VEGFR-2. In addition,in silico, ADMET and toxicity studies showed a high level of drug likeness for the synthesized compounds.
Abulkhair, Hamada S.,Eissa, Ibrahim H.,El-Adl, Khaled,ElSohly, Mahmoud A.,Elhendawy, Mostafa A.,Mehany, Ahmed. B. M.,Metwaly, Ahmed M.,Radwan, Mohamed M.,Sakr, Helmy M.,Yousef, Reda G.
p. 16949 - 16964
(2021/09/27)

Photoinduced Iron-Catalyzed ipso-Nitration of Aryl Halides via Single-Electron Transfer
A photoinduced iron-catalyzed ipso-nitration of aryl halides with KNO2 has been developed, in which aryl iodides, bromides, and some of aryl chlorides are feasible. The mechanism investigations show that the in situ formed iron complex by FeSO4, KNO2, and 1,10-phenanthroline acts as the light-harvesting photocatalyst with a longer lifetime of the excited state, and the reaction undergoes a photoinduced single-electron transfer (SET) process. This work represents an example for the photoinduced iron-catalyzed Ullmann-type couplings.
Wu, Cunluo,Bian, Qilong,Ding, Tao,Tang, Mingming,Zhang, Wenkai,Xu, Yuanqing,Liu, Baoying,Xu, Hao,Li, Hai-Bei,Fu, Hua
p. 9561 - 9568
(2021/08/06)

Catalytic production of anilines by nitro-compounds hydrogenation over highly recyclable platinum nanoparticles supported on halloysite nanotubes
Pt-nanoparticles supported on halloysite-nanotubes (HNTs) were selectively deposited onto the inner (Pt(IN)/HNT) or outer (Pt(OUT)/HNT) surface of the support to evaluate their operational stability on the cleaner and efficient hydrogenation of nitro compounds to produce their corresponding anilines. The formation of Pt0-aggregates on the inner or outer surfaces was observed, with mean particles sizes of 2.4–2.9 nm. The catalysts were evaluated using ethanol as solvent and nitrobenzene as a model substrate at a temperature of 298 K, under 1 bar of H2 pressure. The Pt(IN)/HNT catalyst showed better catalytic performance than Pt(OUT)/HNT, which was mainly attributed to the confinement effect of the Pt-nanoparticles inside the HNTs. However, the operational stability showed that Pt(OUT)/HNT retained its catalytic performance after 15 cycles, while the Pt(IN)/HNT catalyst suffered deactivation after the 5th cycle. The best catalytic system showed a moderate-to-high efficiency in the efficient hydrogenation of 7 nitro compounds used to produce their corresponding anilines, which are important pharmaceutical building blocks.
Aepuru, Radhamanohar,Bustamante, Tatiana M.,Campos, Cristian H.,Leal-Villarroel, Edgardo,Mangalaraja, Ramalinga Viswanathan,Shanmugaraj, Krishnamoorthy,Torres, Cecilia C.,Vinoth, Victor
(2021/07/28)

Copper-mediated simple and direct aerobic oxidative esterification of arylacetonitriles with alcohols/phenols
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
(2020/10/20)

Benzo imidazo [2, 1-b] thiazole compound and application thereof (by machine translation)
The invention discloses a benzoimidazo [2, 1-b] thiazole compound and application thereof, and belongs to the technical field of medicines. The inhibitory activity of the synthesized benzimidazo [2, 1-b] thiazole analogues on FLTT3 is more than 90%, wherein the compounds (compounds 2 , 4, 6, 8 and 10) are IC of FLTT3-ITD kinase. 50 Lower value, in particular compound 2, IC IC50 The value is only 5.60 nm, and therefore the compound of the present invention may be used as an inhibitor FLTT3, or for preparing a drug capable of modulating or suppressing diseases associated with abnormal cell proliferation by affecting the enzymatic activity of one or more tyrosine kinases and interfering with aberrant cell proliferation, having a wide application prospect. (by machine translation)
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Paragraph 0099-0101

(2020/07/15)

Oxidative Esterification of Aldehydes and Alcohols Catalyzed by Camphor-Based Imidazolium Salts
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
p. 1812 - 1820
(2020/01/11)

Green synthesis of zinc oxide particles with apple-derived compounds and their application as catalysts in the transesterification of methyl benzoates
ZnO nanoparticles (ZnONPs) were successfully synthesized using bravo-de-esmolfe apple extract in aqueous medium at room temperature. ZnO microparticles, prepared with a pure apple phytochemical, quercetin (ZnOq), or without phytochemicals (ZnO) were studied for comparative purposes. The re-use of apple waste for highly efficient catalyst production, based on green synthetic routes, can be added to the concept of a circular economy. The synthesized ZnO particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2adsorption/desorption Brunauer-Emmett-Teller (BET) theory. The XRD patterns indicated the formation of a hexagonal wurtzite phase with high purity and SEM and TEM analyses revealed the morphology of the particles. The apple extract produced spherical ZnONPs composed of round lamina-like structures, similar to the micro sized lamina-like shape of ZnOq and dissimilar to the flower-like shape of ZnO. The green synthesized ZnO nanoparticles (ZnONPs) led to a high product yield ofca. 96% within 24 h of reaction time in the transesterification reaction of different carboxylic esters.
Alegria, Elisabete C. B. A.,Alves, Marta M.,Fátima Montemor, M.,Pombeiro, Armando J. L.,Ribeiro, Ana P. C.,Saraiva, Marta S.,Soliman, Mohamed M. A.
p. 6488 - 6494
(2020/06/03)

Nickel-Catalyzed Esterification of Amides Under Mild Conditions
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
p. 874 - 880
(2019/11/13)

New imidazo[2,1-: B] thiazole-based aryl hydrazones: Unravelling their synthesis and antiproliferative and apoptosis-inducing potential
Herein, we have designed and synthesized new imidazo[2,1-b]thiazole-based aryl hydrazones (9a-w) and evaluated their anti-proliferative potential against a panel of human cancer cell lines. Among the synthesized compounds, 9i and 9m elicited promising cytotoxicity against the breast cancer cell line MDA-MB-231 with IC50 values of 1.65 and 1.12 μM, respectively. Cell cycle analysis revealed that 9i and 9m significantly arrest MDA-MB-231 cells in the G0/G1 phase. In addition, detailed biological studies such as annexin V-FITC/propidium iodide, DCFH-DA, JC-1 and DAPI staining assays revealed that 9i and 9m triggered apoptosis in MDA-MB-213 cells. Overall, the current work demonstrated the cytotoxicity and apoptosis-inducing potential of 9i and 9m in breast cancer cells and suggested that they could be explored as promising antiproliferative leads in the future. This journal is
Babu, Bathini Nagendra,Devi, Ganthala Parimala,Kamal, Ahmed,Kumar, C. Ganesh,Rani Routhu, Sunitha,Shareef, Mohd Adil
supporting information
p. 1178 - 1184
(2020/11/03)

Selective hydrogenation of nitroarenes under mild conditions by the optimization of active sites in a well defined Co?NC catalyst
The catalytic hydrogenation of aromatic nitro compounds containing multiple functional groups into amino compounds with high conversion rates, selectivity, and stability under mild conditions is a great challenge. Herein, a well defined catalyst (Co?NC) is prepared through the pyrolysis of the Co-centered metal-organic framework (MOF) at the optimized temperature. The as-synthesized catalyst exhibits a high conversion rate and selectivity for the hydrogenation of 12 aromatic nitro compounds with different competing groups into desired amino compounds with hydrazine hydrate under mild conditions (80 °C, 30 min, and 1 atm). The catalyst also shows excellent stability and can be reused over 20 times without considerably losing its activity. It is found that the Co-Nx site is the main active site for catalytic hydrogenation, and the Mott-Schottky effect between the surface Co NPs and N-doped carbon can further promote the hydrogenation reaction. EXAFS, TEM, XPS, and Raman analyses confirm that cobalt nanoparticles (NPs) are properly encapsulated by the N-doped carbon matrix at the optimized temperature, and the Co species maintain a high spin state after the catalysis, which may be responsible for the high performance of Co?NC. This work demonstrates not only a highly efficient catalyst for hydrogenation under mild conditions, but also provides insight into the active sites in Co-based catalysts for hydrogenation.
Chen, Shuo,Jiang, Hong,Jiang, Shun-Feng,Ling, Li-Li
supporting information
p. 5730 - 5741
(2020/09/21)

Metal-Free Oxidative Esterification of Ketones and Potassium Xanthates: Selective Synthesis of α-Ketoesters and Esters
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
p. 5220 - 5230
(2020/05/18)

Camphoryl imidazole type ionic liquid and preparation method and application thereof
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; 0065

(2019/10/05)

Metal-free aerobic oxidative esterification of aromatic aldehydes promoted by potassium fluoride (KF)
We investigated the oxidative esterification of aldehydes with alcohols/phenols to produce a range of esters. In this approach, we conducted the reaction under metal-free conditions at room temperature. The reactions were promoted by potassium fluoride (KF) as the additive, resulting in the desired product in good to high yields. This procedure was found to be effective for the production of aryl esters, which are challenging in most of the available reports. It is vital for this procedure not to exclude air as the source of oxygen.
Soltani, Roghaye,Ghaderi, Arash
p. 1572 - 1576
(2019/06/24)

ZnO nanoparticles: An efficient catalyst for transesterification reaction of α-keto carboxylic esters
Pure ZnO nanoparticles were synthesized by a sustainable precipitation method using zinc nitrate and sodium hydroxide in aqueous medium at room temperature. They were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM-EDX), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV–vis) spectroscopy and Brunauer-Emmett-Teller (BET) analysis. The XRD patterns indicate the formation of the hexagonal wurtzite phase with high purity and SEM-EDS analysis confirm the purity and a homogenous distribution of the nanostructures. The ZnO nanostructures present plate-like agglomerates, resulting in a quasi-spherical morphology. The catalytic activity of the formed ZnO nanoparticles was evaluated towards the transesterification reaction of different carboxylic esters in the presence of various alcohols. This catalyst is highly selective for the transesterification of α-keto carboxylic ester (methyl benzoylformate) and leads to ca. 97percent of product yield within 24 h of reaction time.
Alegria, Elisabete C. B. A.,Karmakar, Anirban,Pombeiro, Armando J. L.,Rúbio, Guilherme M. D. M.,Ribeir, Ana P. C.,Saraiva, Marta S.,Soliman, Mohamed M. A.,da Silva, M. Fátima C. Guedes
(2019/09/06)

Construction of Esters through Sulfuryl Fluoride (SO 2 F 2) Mediated Dehydrative Coupling of Carboxylic Acids with Alcohols at Room Temperature
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
p. 3901 - 3907
(2019/10/11)

For amino benzoic amide of environment-friendly production process
The invention relates to a to amino benzoic amide of environment-friendly production process, the process utilizes the nitro benzoic acid and passes through mellowly catalytic esterification reaction generating P-nitro-benzoic acid ester, then the hydrogenation catalyst, the presence of hydrogen, ammonia solution amidation reaction for preparing P-benzamide. The present invention the used raw materials are cheap and easily obtained, the operation is simple, small amount of waste water, the operation safety is high, the reaction selectivity is high, high product yield and purity, low cost.
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Paragraph 0034-0036; 0040-0042; 0045-0047; 0050-0052; 0056

(2019/07/11)

METHOD FOR THE SYNTHESIS AND PURIFICATION OF ARYL ACID ESTERS
The general inventive concepts are directed to the discovery that certain aryl acids can be esterified under particular conditions to provide the resulting ester as a solid that precipitates in good yield from the reaction mixture. The esters may then be isolated and purified with relative ease. Accordingly, a method for the esterification, isolation, and purification of aryl acids is provided.
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Paragraph 0028

(2019/10/17)

Synthesis and biological evaluation of novel disulfides incorporating 1,3,4-thiadiazole scaffold as promising antitumor agents
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
p. 1502 - 1508
(2019/07/30)

Synthesis, characterization and assessment of local anesthetic activity of some benzohydroxamic acids
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
p. 181 - 185
(2018/12/11)

Synthesis and anticancer evaluation of new lipophilic 1,2,4 and 1,3,4-oxadiazoles
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
p. 18 - 30
(2019/01/16)

Copper-catalyzed demethylative esterification of arylmethylketones: a new route for the synthesis of benzocaine
An efficient method for oxidative cleavage of C(CO)–C bonds of ketones has been developed. This procedure enables activated methyl ketones to react with tetraethyl orthosilicate for generation of the corresponding methyl esters using copper as the catalyst. Primary mechanistic studies revealed that in contrary to other related studies, the involvement of the aldehyde as the intermediate of this reaction is highly probable. Interestingly, this study provides an unprecedented positive effect of the elemental sulfur upon this oxidative esterification reaction. As an application of our method, we have reported a two-step procedure for the synthesis of benzocaine. The second step of this procedure involves a highly selective reduction in nitro group in the presence of ester functionality.
Roodan, Sajedeh Maddah,Ghaderi, Arash
p. 2327 - 2332
(2019/06/27)

Carbonylative Suzuki coupling and alkoxycarbonylation of aryl halides using palladium supported on phosphorus-doped porous organic polymer as an active and robust catalyst
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
(2018/12/11)

Facile, highly efficient and environmentally friendly transesterification mediated by platinum dioxide and nickel oxide under essentially neutral conditions
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
p. 2465 - 2471
(2018/06/11)

A two chlorine two (1 - butyl imidazole) zinc catalyst preparation method and application of (by machine translation)
The invention discloses two chlorine two (1 - butyl imidazole) zinc catalyst preparation method, the method will be 1 - butylimidazole, vanadyl acetylacetonate, zinc acetate NaOAc - HOAc add to a buffer solution, then adding an appropriate amount of sodium chloride, mixing, heating, cooling, get the tuberous two chlorine two (1 - butyl imidazole) zinc catalyst. The method of the invention has simple reaction process, after treatment is simple. In the 4 - nitro-benzoic acid methyl ester b in the esterification reaction, yield is as high as 93%. (by machine translation)
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Paragraph 0039

(2018/07/07)

Improving the Potency of Cancer Immunotherapy by Dual Targeting of IDO1 and DNA
Herein we report the first exploration of a dual-targeting drug design strategy to improve the efficacy of small-molecule cancer immunotherapy. New hybrids of indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors and DNA alkylating nitrogen mustards that respectively target IDO1 and DNA were rationally designed. As the first-in-class examples of such molecules, they were found to exhibit significantly enhanced anticancer activity in vitro and in vivo with low toxicity. This proof-of-concept study has established a critical step toward the development of a novel and effective immunotherapy for the treatment of cancers.
Fang, Kun,Dong, Guoqiang,Wang, Hongyu,He, Shipeng,Wu, Shanchao,Wang, Wei,Sheng, Chunquan
supporting information
p. 30 - 36
(2017/12/26)

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
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
p. 801 - 811
(2019/02/27)

Unprecedented alkylation of carboxylic acids by boron trifluoride etherate
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
p. 387 - 392
(2018/09/06)

Fe-catalyzed esterification of amides via C-N bond activation
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
p. 4571 - 4576
(2018/02/09)

Highly efficient and green esterification of carboxylic acids in deep eutectic solvents without any other additives
A protocol that carboxylic acids esterifies with the quaternary ammonium salt of deep eutectic solvent (DES) is presented, which opens a new access to ester using DES as alkylating agent, solvent, and catalyst. The reaction runs smoothly in DES without any other additives. Substituted cinnamic acids, aromatic acids, and aliphatic acids can be esterified in moderate to good yields. The advantages of this reaction include excellent functional group compatibility and simple reaction procedure.
Yasmin, Sumera,Sheng, Wen-Bing,Peng, Cai-Yun,Rahman, Atta-ur,Liao, Duan-Fang,Choudhary, M. Iqbal,Wanga, Wei
supporting information
p. 68 - 75
(2017/12/26)

Porous organic cage stabilised palladium nanoparticles: Efficient heterogeneous catalysts for carbonylation reaction of aryl halides
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
supporting information
p. 2796 - 2799
(2018/03/21)

Solvent- and Metal-free Oxidative Esterification of Aromatic Aldehydes Using Urea-2,2-dihydroperoxypropane as a New Solid Oxidant
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
p. 303 - 309
(2017/03/27)

Zinc Complexes with Cyanoxime: Structural, Spectroscopic, and Catalysis Studies in the Pivaloylcyanoxime-Zn System
Reaction of 2-hydroxyimino-4,4-dimethyl-3-oxo-pentanenitrile (common abbreviation HPiCO, pivaloyl-cyanoxime) with zinc sulfate in an aqueous solution results in the formation of the two new complexes: [Zn(PiCO){H(PiCO)2}(H2O)] (I) and tetranuclear Zn complex [Zn4(μ3-OH)2(PiCO)6 (H2O)4] (II). Both complexes were characterized by elemental analysis, IR- and UV-visible spectra, DSC/TGA studies, and X-ray analysis. In complex II, the PiCO- cyanoxime anion adopts three bidentate binding modes: O-monodentate, chelating (κ2), and bridging (2) coordinations. Also, the ligand represents the mixture of two diasteromers (cis-anti and cis-syn) that form five- and six-membered chelate rings with Zn atoms and cocrystallize in one unit cell at population of 0.57-0.43. There are two crystallographically different Zn-centers in the ASU, and two μ3-bridging hydroxo-groups arrange via inversion center the formation of an elegant tetranuclear complex. Each Zn atom has a molecule of coordinated water and is in the distorted octahedral environment. Because of the structural flexibility and multidentate propensity of the pivaloyl-cyanoxime, complex II may act as a structural model of naturally occurring Zn-containing enzymes. Indeed, compound I exhibits an efficient catalytic performance for transesterification reaction of various esters in ethanol under mild reaction conditions. Therefore, obtained results allow assignment of observed activity as green catalysis.
Opalade, Adedamola A.,Karmakar, Anirban,Rúbio,Pombeiro, Armando J. L.,Gerasimchuk, Nikolay
p. 13962 - 13974
(2017/11/24)

Graphene Oxide: An Efficient Acid Catalyst for the Construction of Esters from Acids and Alcohols
Graphene oxide was found to be an efficient and reusable acid catalyst for the esterification reaction. A wide range of aliphatic and aromatic acids and alcohols were compatible with the standard conditions and afforded the corresponding products in good yields. The heterogeneous catalyst can be easily recovered and recycled in dichloro-ethane solvent with good catalytic activity.
Chen, Zhengwang,Wen, Yuelu,Fu, Yejuan,Chen, Hai,Ye, Min,Luo, Guotian
supporting information
p. 981 - 985
(2017/05/05)

USE OF DDX3 INHIBITORS AS ANTIPROLIFERATIVE AGENTS
The present invention refers to compounds of formula I or II endowed with DDX3 inhibitory activity, relative pharmaceutical compositions and their use as antihyperproliferative agents. (I) or (II)
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Page/Page column 91

(2017/10/30)

Synthesis and Biological Activity of Anthranilic Diamide Derivatives Incorporating 1,3,4-oxadiazole or Nitrogen-containing Saturated Heterocyclic Moieties
A series of novel anthranilic diamide derivatives incorporating 1,3,4-oxadiazole or nitrogen-containing saturated heterocyclic moieties were synthesized, characterized, and evaluated for bacteriostatic activity against three phytopathogenic bacteria Xanthomonas oryzae pv. Oryzae (Xoo), Xanthomonas axonopodis pv. Citri (Xac), Ralstonia solanacearum (R. solanacearum). The preliminary biological results indicated that most compounds exhibit bacteriostatic activity against three phytopathogenic bacteria. Among these compounds, compounds 6g, 6f, and 6i displayed better antibacterial activity. In the test with concentration of 200 μg/mL, antibacterial activity of compound 6i and 6j was 96%. In particular, the bacteriostatic activity displayed by compound 6h against Xoo is similar to the one displayed by commercial drug bismerthiazol.
Zhou, Wen-Juan,Zhang, Li,Xiao, Wei,Chen, He-Ju,Wu, Wen-Neng,Ouyang, Gui-Ping
p. 1423 - 1429
(2017/03/27)

Synthesis and biological activities of cyclanone O-(2-(3-aryl-4- amino-4H-1,2,4-triazol-3-yl)thio)acetyl)oxime derivatives
Twelve cyclanone O-(2-(3-aryl-4-amino-4H-1,2,4-triazol-3-yl)thio)acetyl)oxime derivatives were synthesized and their structures were confirmed by spectroscopy (IR, 1H NMR, 13C NMR, 19F NMR) and elemental analysis. Their antifungal and antibacterial activities were evaluated against six fungi (Gibberella zeae, Fusarium oxysporum, Clematis mandshurica, Phytophthora infestans, Paralepetopsis sasakii, Sclerotinia sclerotiorum) and two bacteria (Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas citri subsp. Citri (Xcc)). The results indicated that most of the title compounds exhibited good antibacterial activities. Among them, compounds 6d, 6g, 6h, and 6j showed better antibacterial activities against Xoo and Xcc than that of the commercial agent thiodiazole-copper.
Chen, Meihang,Chen, Lijuan,Zhu, Xuesong,Wang, Xiaobin,Li, Qin,Zhang, Juping,Lu, Daowang,Xue, Wei
p. 1259 - 1263
(2017/10/18)

One-pot dichlorinative deamidation of primary β-ketoamides
An approach to the dichlorinative deamidation of primary β-ketoamides through ketonic cleavage is described, and a series of α,α-dichloroketones were furnished mostly in the presence of TEMPO. Based on control experiments, a mechanism involving tandem dichlorination and deamidation is proposed to interpret the observed reactivity.
Zheng, Congke,Zhang, Xiaohui,Ijaz Hussain, Muhammad,Huang, Mingming,Liu, Qing,Xiong, Yan,Zhu, Xiangming
supporting information
p. 574 - 577
(2017/01/16)

Synthesis, molecular structure, spectral analysis and cytotoxic activity of two new aroylhydrazones
Two new aroylhydrazones viz 4-nitro-N′-(1-(pyridin-2-yl)ethylidene)benzohydrazide, NPHY (4) and 4-nitro-N′-(1-(thiophen-2-yl)ethylidene)benzohydrazide, NPHT (5) have been prepared and characterized by 1H NMR, 13C NMR, FT-IR, UV–Visible spectroscopy and mass spectrometry. All quantum calculations were performed at DFT level of theory using B3LYP functional and 6-31G (d,p) as basis set. TD-DFT calculated electronic transitions are found to be in good agreement with experimental findings. The assignments for normal vibrational modes have been done by computing Potential Energy Distribution (PED) using Gar2ped. HOMO-LUMO analysis was performed and reactivity descriptors were also computed. Global electrophilicity index (ω) of 6.12–6.26 eV shows these aroylhydrazones to be strong electrophiles. Intramolecular interactions were analyzed by ‘Atoms in molecule’ (AIM) approach. Also, the computed first static hyperpolarizabilities (β0) of these hydrazones indicate their future application as an attractive non-linear optical (NLO) material. Cytotoxicity evaluated by MTT assay, suggested that the synthesized aroylhydrazones significantly reduce the cell viability of breast cancer cell lines (MCF7) and human prostate adenocarcinoma (DU145) in a dose dependent manner. Cytotoxic potencies (IC50) of these hydrazones against MCF7 and DU145 cell lines were found in range of 54.67–85.67 μM. The result of ROS activity provides supportive data for molecular mechanism of these hydrazones, which is related to apoptotic cellular death. Nuclear condensation assay performed by DAPI staining shows fragmented and condensed nuclei in MCF7 cells, suggesting cell death by apoptosis.
Singh, Ravindra Kumar,Singh, Ashok Kumar,Siddiqui, Sahabjada,Arshad, Mohammad,Jafri, Asif
p. 82 - 97
(2017/02/05)

Design and optimization of N-acylhydrazone pyrimidine derivatives as E. coli PDHc E1 inhibitors: Structure-activity relationship analysis, biological evaluation and molecular docking study
By targeting the thiamin diphosphate (ThDP) binding site of Escherichia coli (E. coli) pyruvate dehydrogenase multienzyme complex E1 (PDHc E1), a series of novel ‘open-chain’ classes of ThDP analogs A, B, and C with N-acylhydrazone moieties was designed and synthesized to explore their activities against E. coli PHDc E1 in vitro and their inhibitory activity against microbial diseases were further evaluated in vivo. As a result, A1–23 exhibited moderate to potent inhibitory activities against E. coli PDHc E1 (IC50 = 0.15–23.55 μM). The potent inhibitors A13, A14, A15, C2, had strong inhibitory activities with IC50 values of 0.60, 0.15, 0.39 and 0.34 μM against E. coli PDHc E1 and with good enzyme-selective inhibition between microorganisms and mammals. Especially, the most powerful inhibitor A14 could 99.37% control Xanthimonas oryzae pv. Oryzae. Furthermore, the binding features of compound A14 within E. coli PDHc E1 were investigated to provide useful insights for the further construction of new inhibitor by molecular docking, site-directed mutagenesis, and enzymatic assays. The results indicated that A14 had most powerful inhibition against E. coli PDHc E1 due to the establishment of stronger interaction with Glu571, Met194, Glu522, Leu264 and Phe602 at active site of E.coli PDHc E1. It could be used as a lead compound for further optimization, and may have potential as a new microbicide.
He, Haifeng,Xia, Hongying,Xia, Qin,Ren, Yanliang,He, Hongwu
p. 5652 - 5661
(2017/10/09)

Synthesis, spectral analysis and antibacterial evaluation of 5-substituted-1,3,4-oxadiazol-2-yl 4-(4-methylpiperidin-1-ylsulfonyl)benzyl sulfides
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
p. 3370 - 3375
(2017/05/22)