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1、PERKINREVIEWSaturatednitrogenheterocyclesAndrewMitchinsonandAlanNadinMerckSharpandDohmeResearchLaboratories,TheNeuroscienceResearchCentre,1TerlingsPark,Harlow,Essex,UKCM202QR.E-mail:andrew_mitchinson@merck.com,alan_nadin@merck.comReceived(inCambridge,UK)16thMay2000Publishedonthe
2、Web15thAugust2000Reviewingtheliteraturepublishedin1999.ContinuingthecoverageinJ.Chem.Soc.,PerkinTrans.1,1999,2553.1Introductionconditions(Scheme2).Thering-openedintermediates42Three-memberedringswereconvertedtothedesiredproducts5usingstandard3Four-memberedringsmethods.4Five-memb
3、eredrings5Six-memberedrings6Pyrrolizidines,indolizidinesandquinolizidines7Mediumandlargerings8Tetrahydroisoquinolinesandtetrahydroquinolines9Methodsforthegeneralsynthesisoftwoormoreringsizes10ReferencesScheme21IntroductionDavisandco-workershavepublishedafullaccountoftheirThisrev
4、iewcoverstheliteraturerelatingtosaturatednitrogenasymmetricaza-Darzensapproachtoaziridine-2-carboxylateheterocyclespublishedin1999.Theclassificationofthechem-5esters8and9,startingfromN-sulfinylimines6(Scheme3).Inistrydescribedissimilartothatfoundintheprevioussurveyinreactionswitht
5、helithiumenolateofmethylα-bromoacetate,ref.1.arangeofcis-aziridines7waspreparedingoodyieldsanddiastereomericexcesses.Theconfigurationoftheproductswas2Three-memberedringscontrolledbythesulfurstereogeniccenter.OxidationoftheAnewmethodforthedeprotectionofN-tosylaziridineshasN-sulfiny
6、laziridines7withMCPBAreadilyaffordedthebeendescribed,usingsodiumnaphthalenidetoaffordtheN-tosylanalogues8.Alternatively,thesulfinylgroupcouldbecorrespondingN–Hcompounds.2Theconditionswerecompat-removedunderacidicorbasicconditions,yieldingN–Hazirid-ciblewitharomaticgroupsandbenzylet
7、hers,butdecompositionines9.DavisandMCoullhaveusedthesameapproachinaofthesubstratewasseenwhenatert-butylesterorbenzoatesynthesisofaziridine-2-phosphonatesandazirinylphosphon-6groupwaspresentattheC-2position.ates.PhenylselenylchloridehasbeenaddedstereoselectivelytoAtkinson’sreagen
8、thasbeenusedfortheregioselectiveazirid-7methoxy
