含氮有机物-大学有机化学

§14含氮有机化合物第十四章含氮有机化合物Nitrocompounds授课学时：10学时第二节胺第一节硝基化合物第三节重氮和偶氮化合物第四节分子重排本章学习要求1.掌握硝基化合物的结构、制法和性质；2.掌握胺的结构、制法和性质；3.掌握重氮化合物的结构、制法和性质；4.掌握亲核重排、理解亲电重排、游离基重排和芳香族重排；5.了解硝基化合物、胺和重氮化合物的用途。第一节硝基化合物CH3CH2NO2NO2CH3硝基乙烷2-硝基甲苯亚硝酸酯硝基化合物RNO2RONOCH3ONO+-12-12两个氮氧键等长=0.121nmNO0.137nmNO0.122nmRNOORNOO+或亚硝酸酯结构RONO一、硝基化合物的制备1.烷烃的硝化2.亚硝酸盐的烃化CH3(CH2)4Br+AgNO2CH3(CH2)4NO2+CH3(CH2)4ONO75~80%14%3.芳烃的硝化二、硝基化合物的化学性质1.还原RNO2[H]RNH2[H]NO2[H]NO[H]NHOHNH22.酸性RCHNOO[]RCHNOHORCHNOHO硝基式酸式NaOH（or假酸式）3.与羰基化合物的反应3HCHO+CH3NO2OH类似羟醛缩合反应——Henry反应HOCH2CCH2OHNO2CH2OH4.与亚硝酸反应RCH2NO2HONORCNOHNO2+H2OR2CHNO2HONOR2CNO2NO+H2OR3CNO2HONO硝肟酸假硝醇溶于NaOH，为红色溶液溶于NaOH，为兰色溶液4.芳香族硝基化合物对取代基的影响（1）影响卤素的活泼性NClOO（2）影响酚的酸性NHOOO一、胺的分类和命名RNH2R2NHR3N季铵化合物：氮原子上连有四个烃基的衍生物第二节胺R4N+X-季铵盐R4N+OH-季铵碱NH3氨10胺20胺30胺NH4+X-铵盐NH4OH普通命名法[简单胺]CH2NHCH3CH2NH2乙胺系统命名[较复杂胺]N-苯基苯甲胺CH3CH2CHCH2CH2CH2CH3CH3CH2CHCHNHCH3NHCH2CH3CH3H3C3-甲基-2-甲氨基戊烷[季铵化合物][(CH3)2CH]4N+I-N+CH3OH-CH2CH2OHCH3CH3氢氧化(2-羟乙基)三甲铵(俗名胆碱)碘化四异丙铵季铵化合物可看作铵的衍生物来命名二、胺的结构孤电子对使胺具有亲核性、碱性;NHH3CHsp3112.9o105.9oCH3N+H5C2CH2CH=CH2phCH3N+C2H5CH2=CHCH2phNR1NR1R2R3R3R2三、胺的化学性质1.碱性RNH2+H2ORNH3++OH-胺的氮原子上有孤对电子，能结合水中的质子RNH2+HXRNH3+X-OH-RNH2分离提纯CH3NH2(CH3)2NH(CH3)3NNH3NH23.383.274.214.769.37碱性强度：脂肪胺氨芳香胺pKb碱性强度：二甲胺甲胺三甲胺（在水溶液中）三甲胺二甲胺甲胺（在气体状态）NNH2CH3NH2O2N13.08.92电子效应：影响碱性强弱的因素：CH3N+CH3CH3HOH2空间效应：溶剂化效应：CH3N+HHHOH2OH2OH2CH3N+CH3HHOH2OH23o胺2o胺1o胺NH31o胺2o胺3o胺1o胺2o胺3o胺2.烷基化RXR4N+X-NH3RXSN2RNH2RXR2NHRXR3N3.酰化与磺酰化RCNR'2+HClORCNHR'+HClORCNH2+HClORCCl+R'NH2ONH3R’2NH氢氧化钠或吡啶RCCl+R'3NORCCl+R'NH2O兴斯堡反应分离鉴别一级、二级、三级胺RNH2R2NHR3NSO2ClSO2NHRSO2NR2不反应（不溶于NaOH水溶液）NaOHSO2NRNa+-RNH2R2NHR3NSO2ClSO2NHRSO2NR2不反应（不溶于NaOH水溶液）NaOHSO2NRNa+-RNH2R2NHR3NSO2ClSO2NHRSO2NR2不反应（不溶于NaOH水溶液）NaOHSO2NRNa+-RNH2R2NHR3NSO2ClSO2NHRSO2NR2不反应（不溶于NaOH水溶液）NaOHSO2NRNa+-RNH2R2NHR3NSO2ClSO2NHRSO2NR2不反应（不溶于NaOH水溶液）NaOHSO2NRNa+-RNH2R2NHR3NSO2ClSO2NHRSO2NR2不反应（不溶于NaOH水溶液）NaOHSO2NRNa+-4.胺与亚硝酸反应CH3CH2CH2++Cl-+N2醇、烯、卤代烃等用于氨基的定量测定CH3CH2CH2NH2NaNO2HCl1o胺CH3CH2CH2N+NCl-重氮盐NH2+NaNO2+HClO~5oC重氮化反应N2+Cl-Ar(R)NH(或R2NH)+HONO2o胺致癌剂3o胺N(CH3)2+HONOR3N+HNO2[R3NH]+NO2-Ar(R)NNO(或R2NNO)N-亚硝基胺ONN(CH3)2(绿色结晶)NH2+3Br2H2ONH2BrBrBr+3HBrNH2(CH3CO)2ONHCOCH3Br2无水CH3COOHNHCOCH3BrNH2BrH+orOH-（1）卤代5.芳核亲电取代反应（2）磺化NH2浓H2SO4N+H3OSO3H180~2000CH2ONHSO3H重排NH2SO3H（3）硝化6.季铵盐与季铵碱CH2N+(CH3)3Cl-•季铵盐的用途作表面活性剂亲油基(烃基)和亲水基(正离子部分)C12H25N+(CH3)3Cl-作相转移催化剂能把反应物从一相转移到另一相的催化剂称为相转移催化剂。R3N+R'IR3N+RI-CH2Cl+(CH3)3N•季铵碱制备R4N+X-+Ag2OH2O强碱季铵碱受热分解(CH3)3N+CH3OH无－H发生SN2反应R4N+OH-+AgXN+CH3CH3CH3CH3OH-130~1350C有－H发生消除反应CH3CH2CHCHCH2H+N(CH3)3HOH-+2N(CH3)3+H2O55.7%1.3%Hofmann消除规则生成双键碳上烷基取代较少的烯烃2CH3CH2CH2CH=CH2+CH3CH2CH=CHCH3CH3CH2CHCHCH2HN(CH3)3HOH[]CH3CH2CH2CH=CH2+N(CH3)3+H2OE2消除主要得到双键碳上取代基较少的烯烃δ+δ-CH3CH2CHCHCH2H+N(CH3)3HOH-季铵碱的用途之一：测定胺的结构彻底甲基化——氮原子上氢均被甲基取代3)CH3CH2CH2N(CH3)2+CH2CH2+H2O3)CH3CHCH2+(CH3)3N+H2OCH3CH2CH2N+CH2CH3OH-CH3CH3CH3CH2CH2N+(CH3)3OH-CH3CH2CH2NHCH2CH31)2CH3I2)Ag2O,H2OCH3CH2CH2N(CH3)21)CH3I2)Ag2O,H2O?试利用彻底甲基化和Hofmann消除确定2-甲基氢化吡咯结构。2次彻底甲基化2次Hofmann消除NHCH3四、胺的制备1.氨或胺的烃基化NH3RXSN2RNH2RXRXRXR2NHR3NR4N+X-CH3ClKNH2/NH3(l)CH3NH2CH3NH2+68%32%CH3ClCl-_CH3CH3NH2CH3NH2+NH2-68%32%（2）腈、酰胺、肟等的还原NOHNa,C2H5OHorLiAlH4NH22.含氮化合物的还原（1）硝基化合物的还原（3）醛酮的还原胺化COH2/Ni+NH3CHNH2COH2/Ni+RNH2CHNHRCOH2/Ni+R2NHCHNR2+NH3RCH2CHORCHCHNH2烯胺RCH2CHNH亚胺H2/NiRCH2CH2NH23.伯胺的特殊制法（1）Gabriel（盖布瑞尔）合成法KOHN-OOKOHH2ORNH2+COO-COO-OOONH3NHOO1oRXSN2NROO（2）酰胺的Hofmann降解RCNH2OBr2,NaOHH2ORNH2第三节重氮和偶氮化合物一、芳香族重氮盐（0~50C）NH2O~5oCN2+Cl-+NaCl+H2ONaNO2+HClNN:+结构与酸性NN:ArOHNNArOH+-碱OOHNNAr碱芳基重氮酸1.被羟基取代（重氮盐的水解）N2+HSO4H+H2O++H2OOH2+N2+++N2OH+N2-H+OH2.被卤素或氰基取代（Sandmeyer反应）N+NX-CuXHClN+NX-CuCNKCN碘代物的制备X+N2（X=Cl、Br）CN+N2IN+NCl-KICuBrHBrClBrHNO3H2SO4NO2NO2ClNaNO2HBrN2+Br-ClFeCl3Cl2HClFeNH2ClBrCl合成用BrCl3.被氢原子取代次磷酸水溶液、乙醇或碱性甲醛溶液+N2N2+Cl-H3PO2H2O+N2N2+HSO4-CH3CH2OH二、偶氮化合物NN+NN+取代发生在羟基(或氨基)对位，对位被占领则发生在邻位1.与酚的偶联（pH=8~10）N2+Cl-+OHNaOHH2ONNOH2.与芳胺的偶联（pH=5~7）N2+Cl-+N(CH3)2CH3COOHH2O对-N，N-二甲氨基偶氮苯NNN(CH3)2偶联反应：重氮盐与酚或芳香胺的反应偶联反应不能在强碱、强酸介质中进行NNO-Na+NR2H+OHH+OH2+NHR2+N2+Cl-NaOHNNOHNaOH强酸强碱N2+Cl-+NH2CH3COONaCH3COOH,200CNNNHPhNH3+Cl-PhNH230~450CNNNH2分子内重排三、重氮甲烷CH2N2：黄色气体，剧毒，易爆炸CH2NNCH2NNCH2NNCH2NN1.与酸反应RCOOCH3+N2生成羧酸甲酯，放出氮气RCOOH+CH2N2反应历程为：-N2RCOOCH3OCH3其他酸性物质也可与CH2N2反应OHCH2N2RCOOH+CH2NNRCOO+CH3NN重氮甲烷--很好的甲基化试剂。Arndt－Eistert（阿恩特-艾斯特）ReactionAg2OH2ORCH2COOHCORClCORCHN22CH2N2CORCH2Cl+N2CH2N2高一级羧酸2.与酰氯反应OCCHRWolff重排CORCHNNClH-Cl-CORCHNNHCH2NNAg2O碳烯烯酮H2ORCH2COOHCORCl+CH2NNCORCHNN_CORCHCORCHNNClH-Cl-CORCl+CH2NNCORCH2NNCl-CORCH2Cl+N2第四节分子重排(MolecularRearrangements）一、亲核重排NucleophilicRearrangement1.碳正离子及其重排反应分子重排：在试剂、加热或其他因素的影响下，分子中某些原子或基团发生转移或分子碳架改变生成新的物质的反应。CCZLCCZL-H+CCZ+12重排CCZ+Nu-H+CCZNuCCZ（1）频哪醇重排PinacolicRearrangementCH3CCH3OHCCH3CH3OHH+H2OCH3CCH3OHCCH3CH3OH2+CH3CCH3OHCCH3CH3+CH3CCH3CCH3CH3OH+CH3CCH3OCCH3CH3CH3CCH3OHCCH3CH3+H+CCR2R1R3R4OHOHH+COHCH2OHPhPh+CCH2OHPhPhPh2CHCHO+CCHOHPhPhHH+-PhCOHCPhOHCH3CH3H+PhCCPhOHCH3CH3+Ph2CHCOCH3CH3H+Ph2CCOH+H3CCH3两个烃基中亲核性大者优先迁移CH3O＞＞＞ClCH2=CH＞R3C＞R2CH＞CH3＞HCCR2R1R3R4OH+CCR2R1R3R4OH+CCR2R1R3R4OHNH2HNO2N2CCR2R1R3R4OH+（2）瓦格涅尔-梅尔外因重排Wagner-MeerweinrearrangementH+CH3CCH3CH3CH2OHH2OCH3CCH3CH3CH2OH2CH3CCH3CH3CH2H+Cl-CH3CCH3CH2CH3（1）贝克曼重排BeckmannRearrangementCRR'NOHH+CR'RNHOCRR'NOH2H2O+_CRR'N