Facile synthesis of tin oxide nanocrystals and their photocatalytic activity

Tin oxide nanociystals with diameters smaller than 10 nm were synthesized using Na2SnO3 and CO2 as reactants and cetyltrimethylammonium bromide（CTAB） as stabilizer under mild conditions.As a mild acidic gas,CO2 is favorable for the accurate adjustment of pH value of Na2SnO3 solution.Stannate salt is stable,cheap and easy in operation.The effects of Na2SnO3concentration,CTAB concentration,aging temperature,and aging time on the nanociystals were studied.It was found that,with the increasing Na2SnO3 concentration,aging temperature and aging time,SnO2 nanociystals size decreases.The formation of SnO2nanociystals can be interpreted by electrostatic-interaction mechanism.SnO2 nanociystals show high photocatalytic activities in the degradation of Rhodamine B solution.The catalytic activity of small nanocrystals is higher than that of large ones.

FACILE SYNTHESIS OF 4-AMINO-4-DEOXY-4'-DEMETHYLEPIPODOPHYLLOTOXIN

4-Amino-4-deoxy-4′-demethylepipodophyllotoxin has been directly synthesized from 4′-demethylepipodophyllotoxin and HN_3 in the presence of BF3·Et_2O,followed by hydrogenation with palladium on charcoal as catalyst.

INSERTION OF PTC-GENERATED DICHLOROCARBENE INTO C-B BO ND.A FACILE SYNTHESIS OF KETONES FROM ALKENES VIA ORGANOBORATES

The insertion of dichlorocarbene generated from chloroform by Phase Transfer Catalysis(PTC)into carbon-boron bond of dialkylborate anions 3,obtained by method A and B,resulted in the formation of the inter- mediates 5,which were oxidized with alkaline hydrogen peroxide to give the corresponding dialkylketones in 36-77.9% yields.

A FACILE SYNTHESIS OF 1.2-BISPYRROLEETHYLENS

1. 2-Bispyrroleethylenes can be easily syntnesized bv cc,-,pt}ng pyrrolealdehyde using TiCl_4/Zn as a catalyst. It was found that when the R group is COMe or CO_2 Et, the product is a mixture of trans and cis isomers, and in the other cases, the products are pure trans isomers.

A FACILE SYNTHESIS OF(±)-MURICATAIN

(±)-Muricatain has been synthesized employing ring opening of allylic alcohol epoxide with lithium acetonitrile and lactonization.

A FACILE SYNTHESIS OF 2-TRIFLUOROMETHYLPYRROLE VIA 1,3-DIPOLAR CYCLOADDITION REACTION OF 2-TRIFLUOROMETHYLOXAZOLONE AND THE ACTIVATED CARBON-CARBON MULTIPLE BOND

The 1.3-dipolar cycloaddition reaction of 2-trifluoromethyl- oxazolone and the activated carbon-carbon multiple bond was studied and gave a convenient way to synthesize 2-trifluoromethylpyrrole derivatives.

A FACILE SYNTHESIS OF HETEROCYCLE SUBSTITUTED CHALCONE AND 5-NITROFURANYL OLEFIN DERIVATIVES

Reaction of heterocycle substituted telluronium salts with aroma- tic aldehydes under mild conditions gave corresponding chalcones.In the presence of dibutyl telluride,2-bromomethyl-5-nitrofuran condensed easily with aromatic aldehydes in THF to afford corresponding olefin derivatives as one-pot reaction.

REACTION OF ORGAINIC-TELLURONIUM YLIDE XI.A FACILE SYNTHESIS OF DERIVATIVES OF BISCYCLOPROPANE

Some telluronium salts react easily with 1,4-bis(3-substituted phenyl-3-oxo-1-propenyl)benzene and 1,5-disubstituted phenyl-1,4-pentadien-3 -one to afford derivatives of biscyclopropanes in 61.8-88.8% yield.

A Facile Synthesis of (-)-5_αH,7β,10_α-Eudesmane-3,1 1-diene

s: The convenient synthesis of (-)-5αH.7β 10α-eudesmane-3. 11-dielle 1 has been achieved in four steps starting from R-(-)-carvone. The key step is the reductive deoxygenation of α,β-unsaturated tosylhydrazone together with the migration of the double bond.

Facile Synthesis of Rose-Like NiO Nanoparticles and Their Ethanol Gas-Sensing Property

In this study, rose-like nickel oxide （NiO） nanoparticles with diameters of 400-500 nm are prepared on ITO glass substrates by simple electrodeposition in NiSO46H20 solution at room temperature followed by oxidation in air. Scanning electron microscopy, x-ray diffraction and a transmission electron microscope are used for analyses of the NiO nanoparticles. The ethanol gas sensitivity of these nanoparticles is studied. The results indicate that the rose-like NiO nanoparticles could be used for the fabrication of ethanol gas sensors to monitor the low concentration of ethanol gas in air. Furthermore, at 5 ppm, the NiO nanorose-based sensors show a high response to ethanol （Rg/Ra = 8.4）.

A FACILE SYNTHESIS OF 2-AND 2,4-UNSATURATED AMIDES

A convenient method for preparing unsaturated amides via telluro- nium salts employing solid potassium carbonate as a base with high stereo- selectivity in excellent yields has been developed.

Facile synthesis and antitumor activity of novel 2-trifluoromethylthieno[2,3-d]pyrimidine derivatives

A series of novel 2-trifluoromethylthieno[2,3-d]pyrimidine derivatives were synthesized by a facile three-step procedure that afforded advantages of mild reaction conditions, simple protocol and good yields. The structures of the final compounds were confirmed by 1R, NMR, El-MS, elemental analysis, and X-ray diffraction. Preliminary bioassay results showed that some of the analogs exhibit excellent antitumor activity against MCF-7 and HepG2, especially compounds 3a, 3b, 3e and 3h exhibited higher activity than the positive control gefitinib.

Facile synthesis of size-tunable stable nanoparticles via click reaction for cancer drug delivery

The stability and size of polymeric nanoparticles are two of the most important parameters determining their pharmacokinetics and tumor/drug accumulation efficiency in cancer-drug delivery. Herein, we report a facile one-pot synthesis of crosslinked nanoparticles(CNPs) with tunable sizes and polyethylene glycol(PEG) shells via click reactions. Simply by adjusting the contents of the macromonomer(PEG monoacrylate) in its reaction with ethylene diacrylate and a crosslinker containing hexa-thiols groups, the sizes of the resulting PEGylated crosslinked nanoparticles could be easily tuned from 10 to 90 nm. These nanoparticle cores could encapsulate hydrophobic drugs such as doxorubicin(DOX), and the unreacted thiol and acrylate groups could be used for drug conjugation or labeling. Thus, the nanoparticles provide a multifunctional platform for drug delivery. In vivo studies showed that the larger nanoparticles(about 83.7 nm) had a much longer blood-circulation time and better tumor-targeting efficiency. One of our most important findings was that the drug encapsulated in the crosslinked nanoparticles, even though little was released at pH 7.4 under in vitro conditions, had much faster blood clearance than the nanoparticles' carrier, suggesting that drug release in the bloodstream was significant.

Graphene/phosphorene nano-heterojunction:facile synthesis, nonlinear optics, and ultrafast photonics applications with enhanced performance

Owing to its thickness-modulated direct energy band gap, relatively strong light–matter interaction, and unique nonlinear optical response at a long wavelength, few-layer black phosphorus, or phosphorene, becomes very attractive in ultrafast photonics applications. Herein, we synthesized a graphene/phosphorene nano-heterojunction using a liquid phase-stripping method. Tiny lattice distortions in graphene and phosphorene suggest the formation of a nano-heterojunction between graphene and phosphorene nanosheets. In addition, we systematically investigate their nonlinear optical responses at different wavelength regimes. Our experiments indicate that the combined advantages of ultrafast relaxation, broadband response in graphene, and the strong light–matter interaction in phosphorene can be combined together by nano-heterojunction. We have further fabricated two-dimensional(2D) nano-heterojunction based optical saturable absorbers and integrated them into an erbium-doped fiber laser to demonstrate the generation of a stable ultrashort pulse down to 148 fs. Our results indicate that a graphene/phosphorene nano-heterojunction can operate as a promising saturable absorber for ultrafast laser systems with ultrahigh pulse energy and ultranarrow pulse duration. We believe this work opens up a new approach to designing 2D heterointerfaces for applications in ultrafast photonics and other research.The fabrication of a 2D nano-heterojunction assembled from stacking different 2D materials, via this facile and scalable growth approach, paves the way for the formation and tuning of new 2D materials with desirable photonic properties and applications.

Phosphonium and arsonium ylides(?)——ⅩⅦ.A facile synthesis of methyl 2,6-bisperfluoroalkylbenzoates via acyclic precursors

The title compounds 6a—6f were prepared with high yield via intramolecular Wittig reaction of methyl 3-perfluoroalkyl-6-perfluoroacyl-2-triphenylphosphoranylidenehex-3,5-dienoates (5a—5i)which were obtained from the reaciton of 3-perfluoroacylprop-2-enylidenetriphenylphos- phoranes(3a—3c)with methyl perfluoroalkynoates(4a—4c).

A Facile and Green Synthesis of Sulforaphane

The compound sulforaphane （SFN, 1） has been synthesized via a facile and green synthetic strategy based on the modification of previous methods. Because of its high bioactivities and rare content in nature, the present work is of great important significance.

A FACILE CHEMICAL SYNTHESIS of PENTADEOXYRIBONUCLEOTIDE d-TGGGT via PHOSPHOTRIESTER METHOD

In this paper,we report the chemical synthesis of oligonucleotide d-TGGGT using phosphotriester method.The protected pentamer d-MmtTGibGibGibT(=p-ClC6H_4-O(O)P)was deblocked by treatment with concentrated ammonium hydroxide and 80% acetic acid.The pure d-TGGGT obtained by chromatorgraphy on DEAE-Sephadex A-25 and Q-Sepharose FF could be hydrolyzed completely and confirmed by base ratio.

A FACILE TOTAL SYNTHESIS OF 6-PENTYL-α-PYRONE

A facile total synthesis of 6-pentyl-α-pyrone 1 has been described.The key step is the treatment of 2-furyl-pentyl-csrbinol 3 with NBS in aqueous tetrahydrofuran(THF).The overall yield is 34%.