efficient catalysts for Suzuki-Miyaura coupling reactions of aryl chlorides.pdf

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1、JournalofOrganometallicChemistry696(2011)3741e3744ContentslistsavailableatSciVerseScienceDirectJournalofOrganometallicChemistryjournalhomepage:www.elsevier.com/locate/jorganchemNHCePd(II)eIm(NHC¼N-heterocycliccarbene;Im¼1-methylimidazole)complexesasefficientcatalystsforSuzuki-Miyauracouplingreact

2、ionsofarylchloridesYi-QiangTang,Jian-MeiLu,Li-XiongShao*CollegeofChemistryandMaterialsEngineering,WenzhouUniversity,ChashanUniversityTown,ZhejiangProvince325035,PRChinaarticleinfoabstractArticlehistory:Anewtypeofwell-definedN-heterocycliccarbene(NHC)-palladiumchloride-imidazolecomplexesReceived12

3、July2011derivedfromIPrHClorIMesHCl,PdCland1-methylimidazoleexhibitshighcatalyticactivityinthe2Receivedinrevisedformroom-temperatureSuzuki-Miyauracouplingreactionsofarylorheteroarylchlorides.Moreover,the18August2011large-scale(20.0mmol)couplingsinthepresenceof0.01mol%catalystloadingcanalsogivet

4、hecor-Accepted23August2011respondingcouplingproductsinhighyields.Ó2011ElsevierLtd.Allrightsreserved.Keywords:N-heterocycliccarbenePalladiumcomplexImidazoleSuzuki-MiyauracouplingreactionSyntheticmethod1.IntroductionandOrgan[16,18],etal.[34e37].Recently,wereportedthesynthesisofanoveltypeofNHC-pall

5、adiumchloride-imidazoleTransitionmetal-catalyzedcross-couplingreactionsareversa-[NHCePd(II)eIm]complexes1derivedfromPdCl,IPrHClor2tilemethodsfortheformationofCeCbonds[1,2].Amongthem,theIMesHCland1-methylimidazole.Inaddition,wefoundthattheseSuzuki-Miyaurareactionsplayimportantrolesinmodernsynth

6、eticcomplexesshowedefficientcatalyticactivitytowardaminationchemistry[3e11].Agreatnumberofcatalyticsystemshavebeenreactionsbetweensecondaryaminesandarylchlorides(Scheme1)developedforthecouplingofarylbromidesandiodideswith[38].Theseresultspromptedustofurtherinvestigateotherappli-arylboronicacidsas

7、wellasarylchlorides,whichareattractivecationsofthesecomplexesinorganicsynthesis.Incontinuingsubstratesbecauseoftheirlowcostandwideavailability,thoughinvestigations,wefoundthattheNHCePd(II)eImcomplexes1theyarerelativelyunreac