Chapter21CarboxylicAcidDerivatives:NucleophilicAcylSubstitutionCarboxylicAcidDerivatives§21.1NomenclatureofCarboxylicAcidDerivativesEstersFunctionalgroupsuffix=alkyl-oateFunctionalgroupprefix=alkoxycarbonyl-orcarbalkoxy-CyclicestersarecalledlactonesAmidesFunctionalgroupsuffix=amide(review)Functionalgroupprefix=carbamoyl-CyclicamidesarecalledlactamsTheprincipalgroupisassignedaccordingtothefollowingpriorities:2-溴丁酰溴乙二酰二氯ChenliBenzylacetate3-Methyl-4-butanolide§21.1.4NomenclatureofAmidesN,N,3-trimethylpentanamideCyclicamidesarecalledlactams§21.2StructureofCarboxylicAcidDerivativesChenliChenliCH3CNAcetonitrileThestrongerthiselectrondonationfromZ,thelesspositivethecarbonylCandthelesselectrophilicthecarbonylgroup.TheabilityofZtodonateelectronsislinkedtoitselectronegativity...themoreelectronegativeZis,thelessthestabilizingeffect.DerivativeTheimportantfeaturesofthecarboxylicacidderivativesthatinfluencetheirreactivityaregovernedbythissubstitutentinthefollowingways:TheeffectthesubstituenthasontheelectrophilicityofthecarbonylC;(reviewsubstituenteffects?)Ifthesubstituentiselectrondonating,thentheelectrophilicityisreduced\lessreactive;Ifthesubstituentiselectronwithdrawing,thetheelectrophilicityisincreased\morereactive;Theabilityofthesubstitutenttofunctionasaleavinggroup;WeakresonancestabilizationChenliVeryeffectiveresonancestabilizationAminesandammoniaareusuallypyramidal(锥体的).Theplanarsp2NsystemallowstheNlonepairtoalignwiththeC=Opsystem(seeimage,otherbondsomitted(省略)forclarity(清楚)TheresonanceinteractionintheamideresultsintheC-Nbondhavingsomedoublebondcharacter(shorter,restrictedrotation)Chenli§21.3NucleophilicAcylSubstitutionofCarboxylicAcidDerivatives§21.3.1OverviewofNucleophilicAcylSubstitutionThedifferenceinnucleophilicacylsubstitutionisthatwhenthenucleophileaddstotheelectrophilicC,itbecomestetrahedralandanintermediateforms,thentheleavinggroupdepartsasshownbelow:§21.3.2NucleophilicAcylSubstitution:ReactiveSystemsNucleophilicAcylSubstitutionforReactiveSystems§21.3.3Nuc