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新的手性配体在不对称Michael反应中的催化性能研究的中期报告.docx

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新的手性配体在不对称Michael反应中的催化性能研究的中期报告 Introduction 不对称Michael反应是一种十分重要的不对称碳-碳键形成反应，其产物酰丙氨酸和其衍生物等在药物和生物活性分子的合成中有着广泛的应用。在不对称Michael反应中，手性配体在催化剂中起到了重要作用，因此合成更加高效、选择性更好的手性配体对于提高不对称Michael反应的催化效率和尽可能降低催化剂用量具有重要的意义。 Inthismid-termreport,weaimtointroducethesynthesisandcharacterizationofanewchiralligandanditspreliminaryapplicationintheasymmetricMichaelreaction. SynthesisandCharacterizationoftheNewChiralLigand Thenewchiralligandwassynthesizedusingastandardsyntheticroute,anditsstructurewasconfirmedby1HNMR,13CNMR,andhigh-resolutionmassspectrometry(HRMS).Theligandfeaturesachiralbisoxazolinebackbone,withtwoimidazoliumgroupsattachedtothecentralcarbonatom(Figure1). Figure1.Chemicalstructureofthenewchiralligand. Theligandwasthenusedtoprepareapalladium(Pd)complex,whichwascharacterizedbyNMRandHRMS.ThePdcomplexshowedgoodsolubilityincommonorganicsolventsandwasstableinair. ThePerformanceoftheNewChiralLigandinAsymmetricMichaelReaction ThepreliminaryapplicationofthenewchiralligandinasymmetricMichaelreactionwasinvestigatedusingα,β-unsaturatedketonesandnitroalkenesassubstrates.ThereactionwascarriedoutinthepresenceofacatalyticamountofthePdcomplexofthenewchiralligandandCs2CO3asthebase. Undertheseconditions,theasymmetricMichaelreactionproceededsmoothlywithgoodyieldsandhighenantioselectivity(Figure2).Theobtainedproductswerecharacterizedby1HNMRandHRMS,andtheenantiomericexcesswasdeterminedbyHPLC. Figure2.TheperformanceofthenewchiralligandinasymmetricMichaelreaction. Conclusion Inthismid-termreport,wereportedthesynthesisandcharacterizationofanewchiralligandbasedonbisoxazoline.WealsodemonstrateditspromisingperformanceintheasymmetricMichaelreaction.OurpreliminaryresultsshowthatthenewchiralligandisapromisingcandidateforfurtherdevelopmentasanefficientandselectivecatalystinasymmetricMichaelreaction.Furtheroptimizationandmechanisticstudieswillbeconductedinthenextstageoftheproject.