有机化学学习笔记第六章卤代烃课件.ppt

1、 CH3CH2CH2Br 1-溴丙烷CH3CHCH3Br2-溴丙烷CH3C-BrCH3CH32-溴-2-甲基丙烷 R-X +Nu-R-Nu +X-CH3C-BrCH3CH3H2OOH-CH3C-OHCH3CH3 Williamson法合成醚：10 RX +RONa R-O-ROHCH3OBrCH2CH2COOHNaH,DMFOCOOHCH3O足量 RBr COOCH3HOOHOHNaH,DMF(R=CH3(CH2)11)COOCH3ROOROR61%NNNNCH3CH3SHBrCH2COOC2H5NaOH/H2ONNNNCH3CH3SCH2COOC2H5 BrCH3COONaH C N(CH3

2、)2ON,N-二甲基甲酰胺，简称DMF，与水互溶的有机溶剂OOCH2ClCH2ClCH3COOHCH3COONaCH2OOCCH3CH2OOCCH3 RX+NH3 RNH2 +HX10 胺RXR2NH20 胺RXR3N30 胺RXR4N X40 胺季胺盐FeCOOCH3(CH2)4ClCH3CH2CH2NH2FeCOOCH3(CH2)4NH(CH2)2CH3 ClCH3Cl2hvNaCNClCH2ClH3+OClCH2CNClCH2COOHClNH2ClCuINHOClClOH CH3CH2BrOHCH3CH2OH +Br反应速率=kCH3CH2BrOH-(CH3)3CBrOH(CH3)3CO

3、H +Br反应速率=k(CH3)3CBr CHDBrCH3S-构型OH-OH-沿C-Br键轴背面进攻中心碳原子。CHDBrCH3HOC-Br键即将断裂，C-OH即将形成，中心碳原子sp2杂化，五个基团连在同一碳原子上，空间比较拥挤；由亲核试剂带来的负电荷被分散。CHDCH3HOR-构型C-Br键彻底断裂，C-OH完全形成，产物的中心碳原子构型发生翻转。CC2H5C3H7BrCH3S-构型C-Br首先断裂，生成碳正离子。CC2H5C3H7CH3aOH-CC2H5C3H7CH3HOR-构型abS-构型bCC2H5C3H7OHCH3亲核试剂从正碳离子两面进攻的几率相等，生成两种结构的产物，为对映体关

4、系。CH3-C-CH2BrCH3CH3OH-很难发生反应。O2NSO3SO3CH3SO3(-OTs)(p-CH3-OTs)(p-NO2-OTs)IBrClH2O(OH-)FCH3CH2CH2CH2OHHBrCH3CH2CH2CH2Br+H2OCH3CH2CH2CH2OHH+CH3CH2CH2CH2 OH2BrCH3S-ClOO+COOCH3CH3HHONaOHCH3S-OOOCOOCH3CH3HHO84%OHNaOH不涉及手性中心的反应，所以产物构型保持CH3OOCCH3HO80%OHNO2OHBrClK2CO3,DMFNO2OClNO2OHCH3K2CO3,DMFNO2OONO2CH3 RO

5、 OH ArO RCOO ROH H2OCH3O CH3CH2O (CH3)2CHO (CH3)3COCH3O CH3CH2O (CH3)2CHO (CH3)3CO亲核性碱性 溶剂极性溶剂质子型 醇、酸、水、氨等可以电离H+偶极型 二甲基亚砜(DMSO)N,N-二甲基甲酰胺(DMF)吡啶非极性溶剂CH3SCH3OHCN(CH3)2O与水互溶的非质子型极性溶剂N(DMSO)(DMF)SN2机理机理SN1机理机理 CH3CH2CH2CH2BrC2H5ONaC2H5OHCH3CH2CH=CH2CH3CH2CHCH3C2H5ONaC2H5OHCH3CH=CHCH3BrCH3CBrCH3CH3C2H5O

6、NaC2H5OHCH3C=CH2CH3C2H5ONaC2H5OHBr+主产物次产物(CH3)3COK(CH3)3COH+主产物次产物Br生生成成取取代代多多的的烯烯烃烃为为Saytzerff消消除除方方向向生生成成取取代代少少的的烯烯烃烃为为Hoffmann消消除除方方向向RX异裂慢反应步骤R +X-H+C=CBrH2OOH取代过程中正碳离子重排BrOH-消除过程中正碳离子重排H2OBrHOH2O表现为亲核性OH-BrOH-表现为碱性 BrHROROH 强碱条件、氟代烃是Hoffmann消除 一般碱性、其它卤代烃是Saytzerff消除 强 碱：(CH3)3COK、NaH、NaNH2 一般碱性

7、：NaOC2H5、NaOHBrHBBrHB半成键状态BrHB具备双键的性质半断键状态-HBr-B消除的立体化学为反式共平面消除 CH3HClHHDNaOCH3CH3DCH3HClHHDNaOCH3CH3HClHDH(a键 e键)构象转换CH3 phCH3HHClDNaOCH3phCH3HHDCl转化为稳定构象phCH3HDClH从反式共平面 消除DClCH3phHHphCH3HHBrNaOCH3phphphHHphHHphBr只能将HBr处于反式BrCH3CH3从反式共平面CH3phphH 消除HBrBrBrHHZnBrBrHHZnOnn=2或61.Br22.NaNH2/NH3(液)On以强碱

8、NaNH2消除2个HBr得到叁键。C3H7-C-C-C-HXHHHHHBC3H7-C-C-C-HXHHHHHBC3H7-C-C-C-HXHHHHHBC-H断键程度C-X断键程度，具有负碳离子性质，只能生成在能够使负碳离子稳定的位置，即有吸电子基团，或是离推电子基团远的地方，最终取代少的烯烃。C3H7-CH2CH=CH2 RX2Li-LiXRLiCuXR2CuLi各种RXR-R二烷基铜锂合成烷烃的方法 RX2Li+LiXRLi有机锂试剂绝对乙醚或绝对四氢呋喃Grignard试剂RXMgRMgX绝对乙醚或绝对四氢呋喃RMgX +HY RH +MgXY HY=各种含活泼氢的化合物 如：酸、醇、水、氨

9、、端炔等。C4H9MgBr +H2O C4H10 MgBrD2ODRMgX +CO2 RCOOMgX RCOOH 增加一个碳的方法H3+ORMgX +O2 ROOMgX ROOHH3+ORMgX +RX R-RR=RCH=CHCH2-phCH2-等活泼卤代烃 RMgX +H-C-HO亲核加成R-C-OMgXHHH3+ORCH2OH增加一个碳原子的伯醇RMgX +亲核取代OR-CH2CH2-OMgXH3+ORCH2CH2OH增加两个碳原子的伯醇RMgX +R-C-HOR-C-OMgXRH亲核加成H3+ORCHOH生成仲醇RRMgX +R-C-ROR-C-OMgXRR亲核加成H3+ORC-OH生成

10、叔醇RRCH3CH2CH2CH2CCH3CH3OHCH3CH2CH2CH2C-OMgBrCH3CH3H3+OCH3CH2CH2CH2BrMg绝对乙醚CH3CH2CH2CH2MgBr CH3CCH3OCH2ClMg绝对乙醚CH2MgClOCH2HO1.H3+O2.OHnn=2或61.CH2=CHCH2MgBrnOH2.H3+O1.Mg/(C2H5)2O O2.3.H3+OOH90%BrOOHBr1.Mg OO2.3.CH3COOHOOHOH75%I2Cu8085%I2Cu98%O2NO2NNO2 R-X +R1B(R2)2 R-R1Pd(或Pd的盐)碱性(R2=OH)CH3OBrB(OH)2+P

11、dCl2(n-C4H9)4NF,400CCH3O98%NNOROR(HO)2BBrBrPd(Pph3)4,K2CO3(1M),DMFNNROROR=C2H5,n-C6H13OROR R-X +CH2=CH-G R-CH=CH-GPd(或Pd的盐)X=I;Br;CF3SO3G=H;R;Ar;CN;COOR;OR;OAc 等FeNPdX2X=Cl,IL*=FeNPdXX=Cl,IPph3R1XHHHR2+HHR2R1碱,L*H2O,1000CR1=H,NO2,OCH3R2=CH3,C2H5,n-C4H9X=I,Br,Cl R-X +HC=C-G R-C=C-GPdCl2(Pph3)2CuI,(C2

12、H5)3N(CH3)2N-C-ClOCH3(CH2)3C CH+Pd(OOCCH3)2,(i-Pr)2NPph2THF,K2CO3(CH3)2N-C-C C(CH2)3CH3OC CHClOCH3+Pd(OSO2Rf8)2/NCH(OCH2CH2Rf8)2C10F18/CH3Rf8=CF3(CF2)7C COCH385%RX RHH2Pt催化加氢条件下卤代烃可以被还原为相应的烃RX RH还原剂还原剂：Na/ROH；NaBH4；LiAlH4；Na/NH3ClCl除催化加氢外的条件CH3CH=CHCH2CH2Br除催化加氢外的条件CH3CH=CHCH2CH3CH=CCH2CH2Br除催化加氢外的条

13、件CH=CCH2CH3 ClH2O-NaOH3700COHClH2O-NaOH1600COHNO2NO2ClH2O1000COHNO2NO2NO2NO2O2NO2NClK2CO31300COHNO2NO2NO2NO2随着吸电子基团数量的增加，反应变得容易。ClNO2NO2ClNH3 H2ONH2NO2NO2ClOH-OHClOHClOHCl加成引入的负电荷可以共振到邻对位，邻对位上的吸电子基团对于分散负电荷，稳定活性中间体有利。-Cl-OH先加成后消除 ClNaNH2NH2ClNaNH2CH3CH3OClNH2H酸碱中和Cl-Cl-先消除苯炔NH2后加成H2NNH3-NH2-H2NHHHH一个是带有负电荷的sp2杂化轨道一个是空sp2杂化轨道，大致肩并肩重叠成键，形成苯炔。NaNH2NH2CH3OClCH3OClNaNH2CH3OClNH2CH3OCl-Cl-OCH3OCH3HHHCH3ONH2OCH3NH2CH3OBrCCH2CH2CH2BrCH3Br足量NaCN不反应消除取代BrC=CHCH2CH2CNCH3