钴(Ⅱ)催化2-乙基-3-甲基吡嗪绿色氧化方法（英文）-豆柴文库

您所在位置：网站首页 / 钴(Ⅱ)催化2-乙基-3-甲基吡嗪绿色氧化方法（英文）.docx / 文档详情

在线预览结束，喜欢就下载吧，查找使用更方便

5 金币

下载文档

/ 2

下载提示

如果您无法下载资料，请参考说明：

1、部分资料下载需要金币，请确保您的账户上有足够的金币

2、已购买过的文档，再次下载不重复扣费

3、资料包下载后请先用软件解压，在使用对应软件打开

文本预览

钴(Ⅱ)催化2-乙基-3-甲基吡嗪绿色氧化方法（英文）
Cobalt(II)catalyzedgreenoxidationof2-ethyl-3-methylpyrazine
Introduction
Cobaltisatransitionmetalwhichiswidelyusedforcatalyzingvariousreactions.Inrecentyears,therehasbeenatrendtowardsdevelopinggreenchemistryprotocolsfororganicsynthesis,whichaimtominimizetheenvironmentalimpactofchemicalreactions.Oneofthekeyaspectsofgreenchemistryistheuseofbenignorrenewablecatalysts.Inthisregard,cobalthasbecomeaninterestingalternativetomoretoxicelementssuchaschromiumandmercury.Inthispaper,wewilldiscussthecobalt(II)catalyzedoxidationof2-ethyl-3-methylpyrazine,areactionwhichcanbecarriedoutinagreenandsustainablemanner.
Oxidationof2-ethyl-3-methylpyrazine
2-ethyl-3-methylpyrazineisaheterocycliccompoundwhichcanbeusedasaflavoringagentinthefoodindustry.Itsoxidationhasbeenthesubjectofmuchresearchduetothepotentialapplicationoftheresultingproductsasintermediatesinthesynthesisofothercompounds.Oneofthemostcommonmethodsfortheoxidationofpyrazinesinvolvestheuseofmetalcatalystssuchaschromiumormanganese.However,thesemetalsaretoxicandhaveanegativeimpactontheenvironment.Cobalt,ontheotherhand,isatransitionmetalwhichiswidelyavailableandhasalowtoxicity.
Cobalt(II)catalyzedoxidationof2-ethyl-3-methylpyrazinecanbeachievedusinghydrogenperoxideastheoxidant.Hydrogenperoxideisaneco-friendlyoxidant,whichdoesnotproducetoxicby-products.Thereactioncanbecarriedoutinthepresenceofaceticacidasasolvent,whichisrelativelybenignandcanbeeasilyrecycled.ThereactioncanbemonitoredusingGasChromatography-MassSpectrometry(GC-MS),whichenablestheidentificationofthereactionproducts.
Mechanismofthereaction
Theoxidationofpyrazinecanoccurbytwodifferentmechanisms:singleelectrontransfer(SET)andhydrogenatomtransfer(HAT).TheSETmechanisminvolvestheformationofaradicalintermediate,whichcanreactwithoxygentoformaperoxideintermediate.TheHATmechanisminvolvestheabstractionofahydrogenatomfromthesubstratebytheoxidant,resultingintheformationofaradicalintermediate.
Inthecaseofthecobalt(II)catalyzedoxidationof2-ethyl-3-methylp