Electrochemical Reduction of Zearalenone

Zearalenone1isolatedfromthemycelliaofthefungusGibberallazeae(FusariumGraminearum)isasubstanceofstrikingphysiologicalactivityexhibitingantibioticestrogenicandantibacterialactivitiesinvitroandinvivol.Itsreducedproduct,a-zearalanol2,hasbeenusedasananabolicagentincattIeandsheepunderthecommercialnameRalgro.Accordingtothereducingagentusedtheb-resorcyclicl4-memberedmacrolide1gavedifferentproducts'.Reductionof1withsodiumborohydrideinmethanolgaveamixtureoftwodiastereomericzearalenols3.Catalytichydrog…     

Selective Reduction of gem-Dichlorocyclopropane Derivatives

Cyclopropane derivatives frequently occur as subunits of some natural products as wellas intermediates of medicines and pesticides'. We are interested in the synthesis of I chloro-2,2,3,3-tetramethylcyclop during our synthesis of some new compounds inasymmetric catalysis and in combinatorial chemistry. Closs has synthesized thiscompound via the addition of manochlorocarbene to alkene2. Safiev obtained it via theaddition of monochlorocarbene in PTC-supersonic conditions3. More recently,Bagdan…     

Reduction of 1-Deoxy-13-oxotaxanes

Reduction of 1-deoxy-13-oxotaxanes has been studied under different reaction conditions. Some interesting reactions were reported.     

Studies on the Electrochemical Reduction of Cyanocobinamide

l.INTR0DUCTIONVitaIninBlz(cyanocobalamin)anditScoenZymesasmostdrip0rtanmoleculeshavebeenextensivelystUdied.However,themetabolicreacti0nsofvitaIninBl2throughWhichtheintuellarconversi0ntoitSc0empeformsinmanunaliancellsarelargelyunkn0wnanduncharacterized[l].SeverallinesofevidencesuggestedthatvitaIninBl2mustbereducedpri0rtoformingitsc0e~es[2].Thus,theconversionofvitaIninBl2toitSc0enZyIneformsincellsneedsreductionreagents,suchasFMNapdNADHwithreducedglutathione[l].lnaddition,itwasreP0r…     

Preparation of Gold Nanorods by Electrolysis:Electrochemical Reduction or Chemical Reduction?

In the synthesis of nanosized materials, to control the particle shape is as important as to control its size, because the properties of the nanoparticles strongly depend on both size and shape. The properties of Au nanorods are different from its spherical counterparts in some ways due to the geometric anisotropy. For example, there are two surface plasmon resonance (SP) peaks in the UV-Vis region for Au nanorods, namely, the transverse (SP_t) peak and the longitudinal (SP₁) peak, respectively, while only one for spherical nanoparticles. Recently, Wang et al.^[1,2] proposed an electrolysis-based method to produce Au nanorods with high throughput for the first time, and it was successfully adopted by El-Sayed et al.^[3,4] in their studies on the optical properties and the thermal/laser induced shape transition of gold nanorods. However, the detailed growth mechanism of Au nanorods in such an approach remains untouched at present stage. To this point, only an ambiguous statement is available in Wang's paper^[1,2] as that "the gold nanorods were converted from the bulk anode most likely at the interfacial region of the cathodic surface and within the electrolytic solution",it is still unclear whether the gold nanorods are formed electrochemically or chemically.     

Reduction of 4-nitrophenol catalyzed by nitroreductase

The reduction of 4-nitrophenol catalyzed by nitroreductase in the presence of NADH was investigated in this paper.4-Amino- phenol and 4-bydroxylamino-phenol were found in the reductive products.The relationship between reaction time and the reductive ratio were studied.The similar reducing ratios of 4-nitrophenol were obtained under aerobic and anaerobic conditions.The results indicated that an oxygen-insensitive reaction was proceeded in the reduction of 4-nitrophenol and nitroreductase was an oxygen- insensitive enzyme.The reductive products of 4-nitrophenol were determined by HPLC and MS.     

Selective Catalytic Reduction of NO with Methane

The removal of nitrogen oxides from exhaust gases has attracted great attention in recent years, and many approaches have been developed depending on the application. Methane. the main component of natural gas, has great potential as a NO reductant. In this paper, a number of catalysts previous reported for this catalytic reduction of NO have been reviewed, including a direct comparison of the relative activities and effective factors of the catalysts. Reaction mechanisnls have also been explored preliminarily.     

Reduction of 1-Deoxy -13–oxotaxanes

Numerous reports have described the semisynthesis of paclitaxel and its anologues from different taxoids 1. However, to the best of our knowledge almost all taxoids have a C-1-hydroxyl. Heretofore, the semisynthesis from taxinine, an abundant natural taxoid lacking of C-1-hydroxyl, has only reached the point of C-13 ketone intermediate 2. We have also encountered difficulties in reducing C-13 ketone to corresponding α- hydroxy group using the same conditions as in total synthesis of paclita…     

Electrochemical Reduction of Benzoylformic Acid in Ionic Liquid

Ionic Hquids possess a number of unique properties that makethem ideal electrolytes. Electrochical reduction of benzoyl-formic acid in room temperature ionic liquids as reaction media could be conducted with excellent performances without any ad-ditional supporting electrolyte. Electrolysis at glassy carbon electrode results in the formation of mandelic acid in 91% yield. And the electrochemical behavior of benzoylformic acid was investigated with the technique of cyclic voltammetry.     

Baker''''s Yeast Mediated Reduction of Optically Active Diketone

Introduction 9-Oxo-10-epi-a-cyperone (1a) is a key intermediate for the synthesis of one kind of natural polyhydroxy-lated agarofuran sesquiterpenoids.1-3 To our knowledge, there is no report on the total synthesis of optically ac-tive polyhydroxylated agarofuran except our group抯 work.2,3 In order to obtain optically pure natural prod-ucts, raising ee value of (-)-1a becomes very important. However, the ee value of (-)-1a, afforded by amino acid catalyzed asymmetric reaction under most favor…     

Free Radical–Mediated Chemoselective Reduction of Enones

A novel methodology has been devised for the chemoselective reduction of enones involving the use of ⁿ Bu₃SnH and azobisisobutyronitrile. The 1,4-reduction of variously substituted α,β-unsaturated cyclic and acyclic enones has been successfully carried out under free radical reaction conditions. The reaction has been determined to proceed via single-electron transfer.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications^® for the following free supplemental resource(s): Full experimental and spectral details.]     

A New Reagent for the Reduction of N-Arylsulfonylimines

Potassiumselenatedborohydride(KBHZSe3),sodiumselenatedborohydride(NaBHZSe3)werepreparedfirstbyLalancetteetall.However,sincethen,therehavebeenlittlereportabouttheirapplication.Wehaveusedpotassiumselenatedborohydrideinformamidetoreducearomaticnitrocompounds,andsuccessfullyobtainedthecorrespondinganilines2.Inaddition,wehavealsoreportedthereductionofarylsulfonylchloridestothecorrespondingdisulfidesbysodiumselenatedborohydriderefluxinginCH,CN'.Fromourresearchwork,KBHZSe3andNaBHZSe3werefou…     

Modification of Carbon Nanotube Powder Microelectrode and Nitrite Reduction

The properties of the carbon nanotube powder microelectroes (denoted CNTPME) are remarkably altered by anodic pretreatment and preadsorption of mediators. It seems that anodic pretreatment leads the long and tangled carbon nanotubes to be partially cut shorter, resulting in more openings as shown by TEM. Besides, the anodic pretreatment may adjust the hydrophobicity of nanotubes to match with that of Os(bpy)3^2 . As a result, the real surface area and the ability of adsorbing mediator Os(bpy)3^2 of the nanotubes are markedly increased so as to effectively catalyze NO2^- reduction in acidic solution.     

Reduction ofβ-amino acids with lithium aluminum hydrids

Summary Some-amino acids were reduced to the corresponding amino alcohols with the aid of lithium aluminum hydride.Deceased.     

Reduction of Aromatic α-Halo Ketones with Metallic Bismuth

Aromatic α-bromo ketones and α-iodio ketones can be reduced by bismuth prepared from NaBH₄ and BiCl₃ in water to their parent ketones in high yields, but aromatic α-chloro ketones should be added to sodium iodide first.     

Effect of Reduction Temperature on Hydrofining Performance of Supported Molybdenum Phosphide Catalyst

A series of supported molybdenum phosphide catalysts were prepared by impregnation method. XRD, TG-DTG, XPS and BET were used to study the phase, compositions and surface areas of the prepared catalysts. A model reactant containing thiophene, pyridine and cyclohexene was used for the measurements of catalytic activities. The effect of reduction temperature on catalytic activities was investigated. The analysis results by XRD and BET are very different when the reduction temperature is changed from 400 to 900 ℃. MoP/γ-Al2O3 catalysts and CoMoP/γ-Al2O3 catalysts prepared at the reduction temperature of 500 ℃ are the most active ones.     

Electrochemical Reduction Characteristics of α-Nitronaphthalene inSulfuric Acid Solution

1-Amino-5-naphtholisanimportantintermediateproductfororganicsynthesis'.Itwastraditionallysynthesizedfroma-nityonaphthalenebychemicalmethod.HO:wever,thechemicalmethodneedstwostepsandproducesalargequantityofwastewater,indicatingthehigherenergyconsumptionandpollution.Inthispaper,theelectrochemicalreductionofa-nitronaphthalenetol-amino-5-naphtholwasfirstputforward,theelectrochemicalreductioncharacteristicsofa-nitronaphthalenetol-amino-5-naphtholwerestudiedandthereactionmechanismwasproposedaswell.…     

Positive Shifts of the Reduction Potentials of C_(60) by Substitution of Cyanogens

ThefindingsthatC6ocanreactwithmetalsanddonorspeciestoformchargetransfersalts,suchassuperconductorK3C6o[l]andchargetransfercomplexeslikeferromagnetreductionpotentials).Tothebestofourknowledge,however,thereareonlyC6oF48[3],3quirone-typemethanofullerene[4],andthreesingly[5,6]-bridgedcompounds[5]whosereductionpotentialsaremorepositivethanthatofC6o'Here,wereporttheelectrochemistryandinsituAIRabsorptionspectroscopyofanewC6oderivative(la),synthesizedinourlaboratory,whosereductionpotentialsaremore…     

Synthesis of N-Squaramidoacids and Their Application in Asymmetric Borane Reduction of Prochiral Ketones

A series of novel N-squaramidoacid ligands were prepared conveniently. Without converting to corresponding amino alcohols, these ligands could be used in asymmetric borane reduction of prochiral aromatic ketones to give secondary alcohols in good to excellent enantiomeric excesses. The results showed that N-squaramidoacids are more efficient ligands than N-sulfonyl amino acids. N-Squaryl proline was proved to be an excellent ligand in this catalytic asymmetric process.     

Preparation of Phenolic Resin/Silver Nanocomposites via in-situ Reduction

Polymer/metal nanocomposites have attracted considerable interest because of their potential application in catalysts, electronics, electromagnetics and nonlinear optics1-3. They have been prepared by blending polymer with nanometer metal particles4, reducing polymer-metal ion complexes with reducing agents5, and reducing metal ions in the polymer matrix by high-energy radial irradiation3. In this paper, we report a new approach to phenolic resin/silver nanocomposites, which have potential a…