Sodium Borohydride–Mediated Transesterification

In the presence of sodium borohydride, esters react with alcohols with formation of the corresponding esters. The reaction is sensitive to the solvent, structure of the ester, and is often concurrent with reduction. Thioesters containing an ester group can be selectively cleaved by the reagent. Both esters and thioesters attached to solid support are resistant toward sodium borohydride. The in situ prepared sodium tetraalkoxyborate is introduced as an efficient reagent and catalyst for transesterification.     

Sn-Mediated Catalytic Asymmetric Reduction of Carbonyl Groups by Sodium Borohydride(or Sodium Borodeuteride)

Two remarkable reducing agents NaBH_4 (or NaBD_4)/SnCl_2(orSnCl_4·2Et_2O) with chiral ligands are applied to the asymmetricreduction of carbonyl compounds with excellent chemical yieldsand enantioselective excesses.     

Polymerization/Depolymerization Mechanism for “Living” Sodium Poly-α-Methylstyryl and Sodium Polystyryl

The equilibrium polymerization of sodium poly--methylstyryl in tetrahydrofuran was studied in the temperature range from -60 to 15°C. For the first time, the reversible process of formation/cleavage of the chemical bond was theoretically analyzed in terms of the electronic excitation views. On this basis a new mechanism of the living polymer depolymerization was proposed. The geometry, electronic structure of the model fragments of living polymers comprised of two units were calculated ab initioby the 6-31G* method. The energies of the triplet excited states belonging to the complex of the reactants, on the one hand, and to the reaction product, on the other, proved to be close. The theoretical activation energies for depolymerization of sodium poly--methylstyryl reasonably agree with the experiment.     

Sn－Mediated Catalytic Asymmetric Reduction of Carbonyl Groups by Sodium Borohydride （or Sodium Borodeuteride）

Two remarkable reducing agents NaBH₄ (or NaBD₄)/SnCl₂(or SnCl₄·2Et₂O) with chiral ligands are applied to the asymmetric reduction of carbonyl compounds with excellent chemical yields and enantioselective excesses.     

Scale Inhibition of Green Inhibitor Polyepoxysuccinic Sodium

Polyepoxysuccinic acid (PESA) is the green water treatment agents recognized all over the world[1-3]. It is found that when PESA is used alone, it had good scale inhibition. PESA should be included in the category of green scale inhibitor. PESA is synthesized with maleicanhydride in the presence of catalysts. The effect on scale-in-hibiting property of the product from amount and feed times of catalyst, the reaction temperature, the reaction time were investigated. The optimum reaction c…     

Pentacoordinated Spirophosphoranes from Amino Acid Sodium Salts

Ihotirlaboratory,aseriesofphoSPhoryatedaIninoacidsandoligopePtideswereSynthesizedbyusingvariousdiaapphocyhitesasthephoSPhoryatingreagents.ItwasfoundthatonceaphorphorylgroupwasintroducedtothefreeaIninoacids,rnanyintereStingbioorgAnccheAnStryreactiollsoccuxred,suchasthepeptideformation,eSterificationandeSterexcha*ngereactiononphoSPhorylgroup.Particularly,thepePtidefonnationunderInildconditionsatnearlyneutralaqueousenvironments,providedanintereStingsceneforthepIebioticopthesisofoligopePti…     

Trifluoromethylation of Carbonyl Compounds with Sodium Trifluoroacetate

In the presence of copper （I） halide as catalyst, a variety of carbonyl compounds could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields.     

Sodium Bismuthate–Induced Oxidation of Baccatin

Sodium bismuthate in acetic acid has proven very effective in the oxidation of allyic alcohols. An extension of this oxidation method using baccatin as the substrate has provided keto‐baccatin, an important compound for the semisynthesis of Taxol and Taxotere.     

FeCl3 · 6H2O-Catalyzed Acceleration of the Acylation of Sodium Azide with N-Acylbenzotriazoles

Catalyzed by ferric chloride hexahydrate (FeCl₃ · 6H₂O), the acylation of sodium azide with N-acylbenzotriazoles was greatly accelerated in a mixed solvent of acetone and water. Thus, good to excellent yields of a variety of acyl azides were obtained at room temperature in a short time. Furthermore, because of the complete conversion of N-acylbenzotriazoles and the easy removal of the by-product, purification by column chromatography was no longer required, which made the protocol suitable for large-scale preparation.

Micelle Formation by Sodium Perfluorooctanoate and Decyltrimethylammonium Bromide in 18-Crown-6 + β-Cyclodextrin + Water Systems

The conductances of sodium perfluorooctanoate (SPFO) and decyltrimethylammoniumbromide (DeTAB) have been determined in 18-crown-6 + water (CR + W). -cyclodextrin + water(CD + W) and in CR + CD + W mixtures with a fixed 0.0151 mol dm^–3 concentration of CR andvarying amounts of CD with overall change in the mole fraction range of CD from 0.0 to 0.5 in CR +CD + W mixtures at 30°C. From the conductivity data, the critical micellar concentration (cmc), thedegree of counter-ion association () the free energy of transfer of the surfactant hydrocarbon chainfrom the medium to the micelle (G _HP ⁰ ), and the free energy of transfer of surface contributions(G _S ⁰ ) of SPFO and DeTAB have been computed. It has been found that the micelles of SPFO arestabilized in CR + W mixtures in comparison to pure water, whereas micelles of DeTAB remain comparatively unaffected upon addition of CR in water. On the other hand, micelles of SPFO andDeTAB are denatured upon addition of CD in CR + CD + W mixtures. The denaturation effect isstronger on the micelles of SPFO in comparison to that of DeTAB.     

Preparation and Crystal Structure of Sodium Hydrogen Epoxysuccinate

1 INTRODUCTION In recent years, sodium hydrogen epoxysuccinatehas gained special attention as a raw material of po-lyepoxysuccinic acid (PESA)[1～3]. We have synthes-ized sodium hydrogen epoxysuccinate by the reac-tion of H2O2 and maleic anhydride in water ca-talyzed by tungstate and obtained its single crystal[1].Its structure was determined by X-ray Nonius CAD4diffractometer. Up to now some crystal structures oforganic carboxyl sodium have been determined[4～6].In this paper we …     

Sodium hydrogen bis­(phenoxy­acetate)

In the title compound, Na⁺·H⁺·2C₈H₇O₃⁻, the anion contains a short Speakman-type hydrogen bond [O⃛O = 2.413 (2) Å]. The anions and the Na atoms lie across twofold axes.     

A Novel Method to Prepare Potassium Sodium Titanate Nanotubes

Potassium titanate whiskers are of great interest for the applications such as friction material, and reinforcement in composite preparation1-4. Since the interest in controlling synthesis one-dimensional (1D) nanostructured alkali titanates or titania, s…     

Studies on the Anionic Species of Sodium Aluminate Solutions

Raman, UV, IR and NMR spectra, activity measurement and quantum chemical calculation methods are used concurrently to study the anionic species of sodium aluminate solutions. It has been found that sodium aluminate solutions with the same composition but different preparative histories may exhibit quite different optical andNMg spectra.Sodium aluminate solutions contain a series of aluminium-containing anions including Al(OH)_4~-,Al(OH)_6~(3-) and [(HO)_3Al-O-Al(OH)_3]~(2-).They may convert into each other but the reactions may be rather slow,so that solutions with the same composition but different preparative histories may have different ratios between various anions, and exhibit different spectroscopic properties.     

Influence of β‐Cyclodextrin on the Mixed Micellization Process of Sodium Dodecyl Sulfate and Sodium Lauroyl Sarcosine and Formation of Inclusion Complexes

In this work, we have studied the influence of different concentrations of β‐Cyclodextrin (β‐CD) on the mixed micellization of anionic surfactants sodium dodecyl sulfate (SDS) and sodium lauroyl sarcosine (SLAS) at different SDS mole fractions (α_SDS). From conductivity data, the critical micellar concentration (cmc), the equivalent ionic conductivities of the monomeric species (Λ_m), the associated species (Λ_assc) and the micelle (Λ_mic), the degree of counterion dissociation (α) in the presence of β‐CD were evaluated from the slope of the conductivity versus concentration plots for the pure and binary mixtures. The apparent cmc of the surfactants vary linearly with the β‐CD concentrations. From the dependence of cmc of the surfactants on β‐CD concentration, we have deduced the association constant (K) of surfactant‐β‐CD inclusion complexes assuming 1∶1 stoichiometry. Theories of Clint, Regular solution, and Motomura's have been used for the evaluation of ideality or nonideality of the mixed system. Mixed micelles were found to be rich in SDS content at the cmc in the presence and the absence of β‐CD. The cmc values have been used to evaluate the transfer of standard free energy of micelles (ΔG⁰ _M,tr) from the aqueous medium to additive medium.     

Mechanically Activated Mixtures of Calcium Chloride with Sodium β-Diketonates

The preparative chemical method, X-ray diffraction analysis, and vacuum sublimation method are used to show that the mechanical treatment of mixtures of calcium chloride with sodium salts of acetylacetone, trifluoroacetylacetone, dipivaloylmethane, or acetylacetoimine induces their interaction, forming volatile calcium -diketonates and sodium chloride. Heating of the reaction mixtures results in sublimation of the obtained calcium -diketonate and nonreacted sodium -diketonate; this is impeded by the formation of poorly volatile forms.     

A Plastic–Crystal Electrolyte Interphase for All-Solid-State Sodium Batteries

The development of all-solid-state rechargeable batteries is plagued by a large interfacial resistance between a solid cathode and a solid electrolyte that increases with each charge–discharge cycle. The introduction of a plastic–crystal electrolyte interphase between a solid electrolyte and solid cathode particles reduces the interfacial resistance, increases the cycle life, and allows a high rate performance. Comparison of solid-state sodium cells with 1) solid electrolyte Na₃Zr₂(Si₂PO₄) particles versus 2) plastic–crystal electrolyte in the cathode composites shows that the former suffers from a huge irreversible capacity loss on cycling whereas the latter exhibits a dramatically improved electrochemical performance with retention of capacity for over 100 cycles and cycling at 5 C rate. The application of a plastic–crystal electrolyte interphase between a solid electrolyte and a solid cathode may be extended to other all-solid-state battery cells.     

Sodium difluoromethanesulfinate—A difluoromethylating agent toward protonated heterocyclic bases

Free radical difluoromethylation of protonated heteroaromatic bases was accomplished using sodium difluoromethanesulfinate in combination with tert-butyl hydroperoxide in a two-phase system (methylene chloride–water) at room temperature. The difluoromethylation products of methyl pyridine-4-carboxylate, pyridine-4-carbonitrile, and 2-amino-1,3,4-thiadiazole were isolated on a preparative scale.