有机化学双语版++Alkynes+3.ppt

Chapter4Alkynes,4.1Nomenclature4.2StructureofAlkynes4.3Reactionsofalkynes4.3.1AcidityofTerminalAlkynes4.3.2ApplicationoftheAcidityofTerminalAlkynesinOrganicSynthesis4.3.3HydrogenationofAlkynes1.Syn-additionofH2:Synthesisofcis-Alkyenes2.Metal-AmmoniaReductionofAlkynesSynthesisoftrans-Alkenes,4.3.4ElectrophilicAdditionofAlkynesa.AdditionofHXb.HydrationofAlkynesc.AdditionofX2d.HydroborationandOxidationofAlkynes4.4OxidationofAlkynes4.5PreparationofUnsaturatedHydrocarbons4.5.1PreparationofalkenesDehydrohalogenationofalkylhalides2.Dehydration(脱水)ofalcohols4.5.1PreparationofAlkynesDehydrohalogenationofvicinalalkyldihalidesb.Alkylationofalkynideions,Alkynes:,Hydrocarbonscontainingacarbon-carbontriplebond.,4.1Nomenclature,P134,4.13,Terminalormono-substituted,Internalordisubstituted,alkynes,(内炔),1-Butyne,Alkenyne(烯炔),3-Penten-1-yne(3-戊烯-1-炔),1-penten-4-yne(1-戊烯-4-炔),1.Numberingstartsfromtheendnearthefirstmultiplebond.,2.Whenthereisachoice,doublebondsreceivelowernumbersthantriplebonds.,4.2StructureofAlkynes,Acetylene(ethyne):,spHybridorbitals,C:,Groundstate,Promotionofelectron,Exitedstate,sp-hybridizedstate,Hybri-dization,Eachsphybridorbital:,50%scharacter50%pcharacter,P18,1.10,Theshapeofansphybridobital:,Thetwosphybrideorbitalsareoriented180awayfromeachother,perpendiculartothetworemainingporbitals.,Ansp-hybridizedcarbonatom:,Geometricstructureofsp-hybridizedCatomsislinear.,Inthemole.ofacetylene,theformationofC-Cbond:sp-spoverlap;,TheformationC-Hbonds:sp-1soverlap.,TheformationoftwoC-Cbonds:2py-2pyoverlapand2pz-2pzoverlap.,TheformationC-Hbonds:sp-1soverlap.,H,H,bond,bond,bond,Carbon-carbontriplebonds,4.3Reactionsofalkynes,4.3.1AcidityofTerminalAlkynes,Acetylene:,Carbanion,Conjugatebase(共轭碱),Acidity:,pKa:3.215.816-172638,4.3.2ApplicationoftheAcidityofTerminalAlkynesinOrganicSynthesis,1.PreparationofMetalAlkynides,Acid-basereaction,P138,4.16,2.FormationofC-CBonds,(SynthesisofAlkynes),Sodiumalkynidesareusefulintermediatesasnucleophile.,:,Primaryhalides,3.Formationofothermetalalkynides,Reagent:NH3solutionofAgNO3orNH3solutionofCuCl,Ch.P77,4.3.3HydrogenationofAlkynes,Ch.P52(五)(1),Syn-additionofH2:Synthesisofcis-Alkyenes,Lindlarcatalyst,Lindlarcatalyst:Pd/CaCO3,Pb(Ac)2-quinoline(喹啉),Quinoline:,P-2catalyst:,(96%),Ch:P53,2.Metal-AmmoniaReductionofAlkynesSynthesisoftrans-Alkenes,4.3.4ElectrophilicAdditionofAlkynes,Reactivity:AlkynesAlkenes,Regioselectivit:FollowMarkov.sRule,a.AdditionofHX,b.HydrationofAlkynes,2-Hexanone,Keto-enoltautomerism(酮式烯醇式互变异构):,c.AdditionofX2,d.HydroborationandOxidationofAlkynes,Ch:P67,6.4OxidationofAlkynes,Aninternalalkynes:,IdentificationofC-Ctriplebonds,6.5PreparationofUnsaturatedHydrocarbons,6.5.1Preparationofalkenes,1.Dehydrohalogenationofalkylhalides:,(脱卤化氢),BromocyclohexaneCyclohexene(81%),2.Dehydration(脱水)ofalcohols,Elimination,6.5.1PreparationofAlkynes,Dehydrohalogenationofvicinalalkyldihalides,Diphenylacetylene(85%),b.Alkylationofmetalalkynide,ProblemstoChapter4.AlkyneP146.4.25(b)4.26(b),(c)4.29(c)4.41Showthereactions.4.424.444.45(c)4.484.524.56,Additionalproblems:1.Predictthe