简介:Highlyselectivedimerizationofα-methylstyrene(AMS)waseffectedusingaBroenstedacidicionicliquid,[Hmim]^+BF4^-,assolventaswellascatalyst,providingtheindustrialhigh-valueolefin,2,4-diphenyl-4-methyl-1-pentene(1-PT).Thedesireddimer1-PTcouldbeobtainedin90%yieldat96%conversioninthedimerizationofAMSunderoptimizedconditions.Featuresoftheprocedureincludeuseofreadilyavailableionicliquid-catalyst,exclusionofvolatileorganicsolvents,higherselectivityandefficiencyfor1-PT.
简介:AnefficientroutetoprepareL-glucoseandL-galactoseisdescribed.TheL-sugarsareachievedbyusingthestrategyofswitchingthefunctionalgroupsatC1andC5ofD-glucoseandD-mannose.TheoxidationandreductionofthesilylenoletheratC1andthelead(IV)tetraacetatemediatedoxidativedecarboxylationatC5arethekeysteps.L-GlucoseandL-galactosearepreparedinaconvenientandinexpensiveway.
简介:[1]BASFUSP4479906[2]BASFBP1443541[3]BASFDE3618265[4]WangL.,WuZ.,ChinaLeather,26(8),11,(1997)[5]YuanL.,DinY.,ChineseChemistryBulletin,(2),19(1988)[6]KurokiH.,ChemistryofDyeingTheory(ChineseTranslation),TextileIndustryPress,Beijing,89(1982)[7]WangS.,LiP.,WuZ.DyestuffIndustry(Chinese),34(4),1,(1997)[8]Tian,Y.,Wu,Z.,Wang,G.,Zhang,S.J.ChineseChem.Eng.,46,156(1995)[9]Tian,Y.,Wang,G.,Wu,Z.,J.ChineseChem.Eng.,47,75(1996)[10]Lycka,A.,DyesandPigment,32,11(1996)[11]Griffith,J.,ColourandConstitutionofOrganicMolecules,AcademicPress,London,191(1976)
简介:Poly(4-vinylpyridine)supportednanoparticleofcopper(Ⅰ)iodideisreportedasagreenandrecyclablecatalystfortheregioselectivesynthesisof1,4-disubstituted-1H-1,2,3-triazolesfrombenzylhalides,sodiumazideandterminalalkynesinwater.Thiscatalystcanberecoveredbysimplefiltrationandrecycledupto8consecutiverunswithoutanylossofitsefficiency.
简介:Sixnewopticallyactivepoly(amide-imide)s(5a-f)weresynthesizedthroughthedirectpolycondensationreactionofN,N'-(4,4'-diphthaloyl)-bis-L-leucine(3)withsixhydantoinderivatives(4a-f).Triphenylphosphite(TPP)/pyridineinthepresenceofcalciumchloride(CaCl_2)andN-methyl-2-pyrrolidone(NMP)weresuccessfullyappliedfordirectpolycondensation.Thepolycondensationreactionsproduceaseriesofnewpoly(amide-imide)s(5a-f)inhighyields,andinherentviscositybetween0.42and0.55dL/g.Theresultingpoly(amide-imide)s(5a-f)werecharacterizedbyelementalanalysis,viscositymeasurements,thermalgravimetricanalysis(TGAandDTG),solubilitytestandFT-IRspectroscopy.
简介:NineteenL-N-2-hydroxyethylaminoacidsandL-N,N-bis(2-hydroxyethyl)aminoacidswerepreparedfromthereactionofchlorohydrinwithL-alanine,L-valine,L-leucine,L-isoleucine,L-phenylalanine,L-serine,L-thrcunine,L-glutamicacid,L-asparticacidandglycine.L-N,N,N’,N’-tetra(2-hydroxyethyl)cystinewaspreparedbythereactionofL-cystinewithchlorohydrin.
简介:Dibromobiphenylreactedwithcynomethylanioninammoniaunderirradiationtoformnucleophilicbis-substitutedproductinhighyieldwithoutsubstantialmonosubstitutedproduct.Quantumyieldsfortheformationsofbis-andmonosubstitutedproductswerefoundtobe85.6and2.3×10-6respectively,whilethecorrespondingpseudo-first-orderrateswere6.9×10-3and5.2×10-10mol.L-1.S-1.Blockupthepossibleelectrontransferof4-brome-4’-cyanomethylbiphenylylradicalanionto4-cyanometbyl-biphenylylradicalandbromineion.
简介:Thesynthesisofopen-fiameworkmetalphosphateshasbeenasubjectofintenseresearchowingtotheirinterestingstructuralchemistryandpotentialapplicationsasionexchangers,catalystsandadsorbents.Alargenumberofthesematerialsaresynthesizedinthepresenceoforganicaminesasstructure-directingagents.Recently,manyresearchactivitieshavefocusedonthesynthesisofinorganic-organichybridframeworks.Ascomparedwithinorganicligands,theadvantageofusingorganicmultidentateligandsistheefficacyofrationaldesignofcrystallinesolidsthroughtheircoordinatingpropensitiesandgeometries.
简介:Thesynthesisandphasebehaviorofaseriesof4’-alkyloxy-4-hydroxybiphenylswerediscribed.Theeffectsofreactionconditionsontheyieldsofproductswereinvestigated.Thecharacterizationsofthermotropicliquidcrystallineproductsforthetypeandthermalpropertiesarediscussedthroughtheuseofdifferentialscanningcalorimetry,polarizingmicroscopy.
简介:Reactionsofthe6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrilederivative1withα-halo-carbonylcompoundsgavetheortho-substitutedintermediates2a-cwhichwereconvertedintofuro[2,3-b]thiopyrano[4,3-d]pyridines3a-cbyfusionofafuranmoietyunderbasicconditions.Furthercyclizationof3a-cledtoafusionofapyrimidinering,yieldingthetetracyclicproducts6,7and8.Inaddition,condensationof6withvariousaromaticaldehydesaffordedthecorrespondingimines9a,b.Mannichreactionof7gaveproducts10a,b.
简介:ByusingOH-terminatedpolyaryletherdendrimerandN-Fmoc-glycineasrawmaterials,thedendriticpolyarylether2-aminoacetate(G3-NH2)wassynthesizedviatwostepreactions.G3-NH2asamacroinitiatorforthering-openingpolymerizationofγ-benzylL-glutamateN-carboxyanhydridewasinvestigated.Itisfoundthattheresultingcopolymerspossessedrelativelyhighmolecularweightandnarrowmolecularweightdistribution(1.12
简介:ConformationofL-lysineinaqueoussolutionwasinvestigatedbylanthanideshiftprobes(Dy,Ho,Er,TmandYb).Reilley’smethodwasemployedtoseparatethecontactanddipolarcom-ponentsofthe13Cparamagneticshifts.ThisstudyrevealsthatCαshifthasthelargestcontactcon-tributionwhiletheothercarbonshiftsaredominatedbythedipolarcontribution.TheaverageoverallconformationofL-lysineinaqueoussolutionisextendedwiththemolecularbackboneintransform.Inthecomplex,lanthanideioncoordinatestothecarboxylgroupwithLn—Obondlength2.2/nandthewholeligandislocatedoutsidethezero-dipolarshiftconeofthelanthanideion.Theelectronicspindensitydistributionontheligandnucleishowsthatthespinpolarizationisthepredominantmech-anismofthecontactinteractionfornucleiincloseproximitytotheboundlanthanideion.
简介:ThesolidcomplexesofCr(AA)2Cl3·nH2OofCrCl3withL-α-aminoacids(AA=Val,Len,Thr,Met,Arg,Phe,TryandHis)havebeenpreparedin95?EtOHmedium,andcharacterizedstructurallybyelementalanalysis,chemicalanalysis,IRspectraandTG-DTG.Theconstant-volumecombustionenergiesofthecomplexeshavebeendetermimedbyRBC-Ⅱtyperotating-bombcalorimeter.Thestandardenthalpiesofformationofthecomplexeshavebeencalculatedaswell,hwichare(-2543.16±3.71)(Val),(-2561.32±4.06)(Leu),(-2284.02±2.95)(Thr),(-1418.77±4.60)(Met(,(-3218.91±4.67)(Arg),(-2643.90±5.02)(Phe),(-1707.18±3.23)(Try)and(-2838.05±3.45)(His)kJ/mol,respectively.