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Diisobutylaluminium hydride (DIBAL-H) promotes secondary rim regioselective bis-de-O-methylation of permethylated β-cyclodextrin (β-CD) to give diol 2. To gain an insight into the mechanism of this remarkable regioselective behavior, two corresponding permethylated β-CDs with an alcohol function at either 2- or 3-position were synthesized in our previous study. As a step further to this work, the two compounds were subjected to deoxygenation reaction with tributyltin hydride in the present of 2,2'-azobisisobutyronitrile affording the corresponding 2- and 3-deoxy permethylated β-CD derivatives (19 and 16). The structures of these two compounds were characterized by 1D and 2D NMR and HRMS. Compounds 16 and 19 were unable to react with DIBAL-H which suggests that O-2A and O-3B are necessary for DIBAL-H promoted bis-de-O-methylation reaction of permethylated β-CD.
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A novel estrogen dendrimer has been synthesized through a combination of divergent and convergent approaches in 9 practical steps and in good yields. It was characterized and confirmed by elemental analysis, FT-IR, MS, 1H NMR, 13C NMR. The dendrimer contains 16 estrone units and is potentially a useful tool for the studies of estrogen actions.
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In this investigation a new strategy involves the one-pot, three-component reaction of malononitrile, salycilaldehyde and phenol derivatives in the presence of high surface area of MgO is extended to the formation of chromeno[3,4-c]chromene derivatives in good to excellent yields in a short reaction time. Also, the three component reactions of an aldehyde such as salycilaldehyde and ketones with malononitril for the formation of chromeno [3, 4-c] pyridines are investigated.
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A simple and efficient synthesis of highly substituted pyrroles was achieved in water medium via multi-component strategy, using amine, DMAD/DEAD as well as phenacyl bromide catalyzed by β-CD. Utilizing this protocol various pyrrole derivatives were synthesized in good to excellent yields.
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A series of novel s-triazolothiadiazoles 3a-h were prepared by condensation reaction of substituted amino triazoles 1a-b with N-phetaloyl-L-amino acids 2a-d in the presence of the phosphoroxy chloride (POCl3) as an anhydrous reagent. The structure of all synthesized compounds was confirmed by IR, 1H NMR, and 13C NMR spectroscopy.
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Tolvaptan is a nonpeptide arginine vasopressin (AVP) V2-receptor antagonist and used in the treatment of heart failure, cirrhosis, syndrome of inappropriate antidiuretic hormone secretion or other high-volume capacity of hyponatremia. The metabolites of tolavaptan are mainly produced by CYP3A4, including two major compounds named DM-4103 and DM-4107. Herein, the chemical synthesis of those two metabolites is described in this article for further study.
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Iodine catalyzed one-pot reactions of salicylaldehyde and dimolecular 1H-indene-1,3(2H)-dione, barbituric acids, 4-hydroxycoumarin, or 4-hydroxy-6-methylpyran-2-one were performed and provided a rapid, convenient and general approach to synthesize the chromene derivatives. 2-(11-Oxo-10,11-dihydroindeno[1,2-b]chromen-10-yl)-1H-indene-1,3(2H)-diones P1−P4 and 10-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-3-methylpyrano[4,3-b]chromen-1(10H)-ones P8−P9 were unprecedentedly prepared and structurally identified by NMR and Mass. The confirmation of structure by single crystal X-ray crystallography is reported for P3.
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A new and green method for the synthesis of α,β-unsaturated arylsulfones had been achieved through the condensation of aromatic aldehydes, chloroacetonitrile, benzenesulfinic acid sodium salt in the presence of 1-butyl-3-methyl imidazolium hydroxide ([bmim]OH) in EtOH under reflux. The ionic liquid was recovered and recycled for subsequent reactions. The advantages of this protocol were non-toxic, easy work-up, and good yields.
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Five organotin(IV) complexes, were obtained by reaction of SnR2Cl2 (R= Ph, Me, Bu) with ONO donor Schiff bases. The synthesized complexes have been investigated by elemental analysis and IR, 1H NMR, and 119Sn NMR spectroscopy. These data show that the Schiff base acts as a tridentate dianionic ligand and coordinates via the imine nitrogen and two oxygen atoms. The X-ray crystallography of complex 4 shows a dimeric structure for this molecule. The in vitro antibacterial activities of the Schiff bases and their complexes have been evaluated against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria and compared with the standard antibacterial drugs.
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K5CoW12O40 was used as a highly effective catalyst for the benzylation of 1, 3-dicarbonyl compounds. β-Keto enol ethers were obtained when cyclic 1, 3–dicarbonyl compounds used in this conditions instead of linear ones. The present methodology offers a practical, simple, mild, environmentally friendly, and time-saving method for etherification. Very low loading of catalyst, ease of workup, ease of handling, and reusability of catalyst are other advantages of this catalyst.
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A series of some new tetrazolo[1,5-a]quinoline based tetrasubstituted imidazole derivatives 6a-l have been synthesized by a reaction of tetrazolo[1,5-a]quinoline-4-carbaldehyde 3a-d, benzil 4, aromatic amine 5a-c and ammonium acetate in the presence of iodine through one-pot multi-component reaction (MCR) approach. All the derivatives were screened for antimicrobial and antituberculosis activity and results worth further investigations.
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An antimetastatic tetrasaccharide T1, ?β-D-Gal-(1→4)-β-D-GlcpNAc-(1→6)-α-D-Manp-(1→6)-β-D-Manp-OMe, was synthesized with two approaches. The first approach was a conventional method employing thioglycoside and Koenigs-Knorr glycosylation reaction in 24% overall yield. The second one was a novel route through the azidoiodo-glycosylation strategy by using 2-iodo-2-deoxylactosyl azide as the donor in 36% overall yield.
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′A facile approach for the first total synthesis of prenylated flavonoids, (±)-abyssinone-VI-4-O-methyl ether 1, (±)-abyssinone- IV-4'-O-methyl ether 2, (±)-abyssinone-V-4'-O-methyl ether 3 and (±)-sigmoidin E 4 has been described. The key intermediate 4-hydroxy-3, 5-di-(3-methylbut-2-enyl)benzaldehyde 6 was also first synthesized that features regioselective prenylation of 4-hydroxybenzaldehyde and crystallizing with petroleum ether from the reaction mixture by freeze-out effect.
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A series of novel 1H-benzimidazol-1-yl acetates and 1H-benzimidazol-1-yl propionates containing 1H-1,2,4-triazole moiety were synthesized under microwave irradiation by multi-step reactions, in yields of 87–94%. Their in vitro antifungal activities against Botrytis cinerea and Sclerotinia sclerotiorum were evaluated by mycelial growth rate method. All the target compounds exhibit high activities against Botrytis cinerea with the EC50 values of 7.96–21.74 μg/mL, higher than that of carbendazim.
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In this work, a kind of preparation method of zwitterionic ion chromatography (ZIC) stationary phase modified with phosphorylcholine (PC) was obtained by hydrolyzing after bonding phosphorylcholine dichloride to diol-silica to better explore the characteristics of the PC groups as ZIC stationary phase ligand in simultaneous separation of acidic proteins and basic proteins. The results showed that two kinds of acidic proteins and three kinds of basic proteins can be separated completely, meanwhile, hen egg white was separated and purified and three kinds of egg white components ovalbumin, G2 ovoglobulin and ovotransfemin proteins were separated completely by one single step on PC-ZIC column, the purity of all proteins reached above 95%. PC-ZIC stationary phase was successfully improved with better separation capacity and selectivity than previously reported in this paper.
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A surface plasmon resonance (SPR) method was presented to discriminate hemodialyzed T-lymphocytes from the normal based on antibody-cell recognition. By dynamic reaction with fixed anti-human CD4 antibody, SPR could offer significant signals to distinguish hemodialyzed patients from the healthy controls within 200 sec after the cell injection in respect of either rising speed or maximum binding capacity (p＜0.01). The ratio method is also used to exclude the non-specific adsorption. The percentage of hemodialyzed patients' CD4+ T cells against the healthy control is 69 ± 18 %. The most attractive of the present method is its ability to detect the intact and label-free lymphocytes, and further to detect the subpopulations, or proteins secreted by the desired lymphocytes subset.
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Using polystyrene (PSt) particles as template, PSt/TiO2 composite particles with AgCl incorporation were prepared through hydrolysis of tetrabutyl titanate in the presence of AgNO3 and NaCl. AgCl doped TiO2 hollow particles were successfully prepared with the PSt/TiO2 composite microspheres pretreated at 180 °C followed by calcination. The morphology of PSt/TiO2 particles and the crystal structures of the AgCl doped TiO2 hollow particles were characterized. The photocatalytic activity of the doped TiO2 hollow particles in degradation of Rhodamine B was tested under UV and visible lights and compared to that with Ag doped TiO2 particles. The results showed that TiO2 hollow particles, either doped with Ag or AgCl, demonstrated higher photocatalytic activity than the pure TiO2 particles. This enhancement in photocatalytic activity was more significant with AgCl doped TiO2 than that with Ag doped, and more distinct when the degradation was done under visible light than that under UV light.
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A novel bovine serum albumin (BSA) imprinted Mn-doped ZnS quantum dots (Mn:ZnS QDs) is firstly reported. The molecular imprinted polymer (MIP) functionalized Mn:ZnS QDs (Mn:ZnS@SiO2@MIP) include the preparation of Mn:ZnS QDs, the coating of silica on the surface of Mn:ZnS QDs, and the functional polymerization by sol-gel reaction using 3-aminophenylboronic acid as the functional and cross-linking monomer in the presence of BSA (Mn:ZnS@SiO2@MIP-BSA), and then the elution of the imprinted BSA on the surface of Mn:ZnS@SiO2QDs. The results showed that the phosphorescence of Mn:ZnS@SiO2@MIP is stronger quenched by BSA than that of non-imprinted one (Mn:ZnS@SiO2@NIP), indicating that the selectivity of the imprinted Mn:ZnS quantum dots towards BSA is superior to that of non-imprinted one.
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Family 373 and 406 of CdS magic-sized nanocrystals (MSNCs) were synthesized by a one-pot non-injection approach and white-light emission was generated from the coexistence of them. This light had excellent color characteristics, as defined by their pure white CIE (Commission International de l’Eclairage) color coordinates (0.328, 0.343), and it correlated with a color temperature of 5696 K. A probable thermodynamic equilibrium was proposed to explain the white-light emission behavior in this letter.
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Graphene/acridine (G-Acr) hybrid structures were synthesized through covalent functionalization of graphene oxide with 9-(4-aminophenyl)acridine (APA) and its derivatives. The G-Acr hybrids were characterized by Fourier transform infrared spectroscopy, ultraviolet visible spectrophotometry, thermal gravimetric analysis and Raman spectroscopy. X-ray photoelectron spectroscopy confirms that the binding energies of APA and its derivatives shifted to higher values, revealing pronounced charge transfer at the interface of graphene and organic molecules.
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Zn-Al layered double hydroxide (LDH) was used as precursor to produce ZnO nanostructures through dissolution of aluminum hydroxide in caustic soda. The Zn-Al LDH could transform into different nanostructures of ZnO on LDH nanosheets and even pure ZnO nanorods under various NaOH concentration. The formed ZnO nanorods vertically aligned on both LDH sides. UV-vis diverse reflectance spectra show that the obtained ZnO nanorods have a band gap of approximately 3.05 eV. Such ZnO/LDH nanostructures might be used as photocatalyst in the organic pollutant decomposition.
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Functional in-chain silyl-hydride (Si-H) SBR copolymers of 4-vinyiphenyldimethylsilanol (VPDMS) and butadiene were synthesized by living anionic polymerization, in which active group Si-H was not lost and its content was controllable. Corresponding self-crosslinking elastomers were obtained by hydrosilation of Si-H group with vinyl bonds in chain. The copolymers and elastomers were characterized by 1H NMR, size exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimety analysis (TGA) techniques.
