鄭州大學(xué) 有機(jī)化學(xué)8鹵代烴 金屬有機(jī)化合物

1、Chapter 8 Halohydrocarbons (鹵代烴鹵代烴)Organometallic Compounds (有機(jī)金屬有機(jī)金屬化合物化合物)8.1 Classification (分類(lèi)分類(lèi)), Nomenclature (命名命名), Structure (結(jié)構(gòu)結(jié)構(gòu)) and Physical Properties (物理性質(zhì)物理性質(zhì))Saturated halohydrocarbons (飽和鹵代烴飽和鹵代烴)Unsaturated halohydrocarbons (不飽和鹵代烴不飽和鹵代烴)Aromatic halohydrocarbons (芳香鹵代烴芳香鹵代烴)按鹵素所連

2、接的烴基的結(jié)構(gòu)分類(lèi)按鹵素所連接的烴基的結(jié)構(gòu)分類(lèi)Benzylic halides(芐型鹵代烴芐型鹵代烴, 芐基鹵芐基鹵)Aryl halides(芳型鹵代烴芳型鹵代烴, 芳基鹵芳基鹵)Allylic halides(烯丙型鹵代烴烯丙型鹵代烴, 烯丙基鹵烯丙基鹵)Vinylic halides(乙烯型鹵代烴乙烯型鹵代烴, 乙烯基鹵乙烯基鹵)Propgarpyl halides(炔丙型鹵代烴炔丙型鹵代烴)按與鹵素相連的碳原子的級(jí)數(shù)分類(lèi)按與鹵素相連的碳原子的級(jí)數(shù)分類(lèi)伯伯(1)鹵代烴鹵代烴仲仲(2)鹵代烴鹵代烴叔叔(3)鹵代烴鹵代烴RCH2X R2CHX R3CX按分子中鹵素的數(shù)目分類(lèi)按分子中鹵素的數(shù)目

3、分類(lèi)一鹵代烷一鹵代烷 多鹵代烷（鄰二鹵代烷多鹵代烷（鄰二鹵代烷 偕二鹵代烷）偕二鹵代烷）CH2Cl2二氯甲烷二氯甲烷8.2 ReactionsNucleophilic Substitution (親核取代親核取代)：SN1/SN2)Nu+R XNu R+X-Elimination Reactions (消除反應(yīng)消除反應(yīng)): E1/E2Reduction (還原還原)+X-C CHXB-C CHB +R XHR HFormation of Organomatelic Compounds (形成金屬有機(jī)化合物形成金屬有機(jī)化合物)8.2.1 Nucleophilic Substitution (親核

4、取代親核取代)8.2.1.1 SN1 and SN2SN2CH3Br + OH-80%C2H5OH55CH3OH + Br-Kineticsbimolecular nucleophilic substitution(雙分子親核取代雙分子親核取代) v= kCH3BrOH-MechanismNu: +C LNu C+ :LNu C Lsingle-step reaction(一步反應(yīng)一步反應(yīng))Stereochemistrysecond order The nucleophile attacks the carbon bearing the leaving group from the BACK

5、SIDE. Inversion of configuration(構(gòu)型翻轉(zhuǎn)構(gòu)型翻轉(zhuǎn)): Walden inversion Energy DiagramSide ReactionE2SN1Kineticsunimolecular nucleophilic substitution(單分子親核取代單分子親核取代) v= kt-BuClMechanismC LC+ :Lcarbocation1)slowMultistep reaction(多步反應(yīng)多步反應(yīng))StereochemistryC+ :NuC Nu2)fastNu-CNufront sideattackC+Nu-CNuback sideat

6、tackRacemizationCOH3CH2CH2CH3CH3CH2CHCOCH2CH2CH3CH3CH2CH3H+CBrH3CH2CH2CH3CH3CH2C+ HBrH2OacetoneCl(CH2)3CH(CH3)2C2H5H3C+60% S(inversion)40% R(retention)(R)-6-Chloro-2,6-dimethyloctane+HO(CH2)3CH(CH3)2C2H5CH3OH(CH2)3CH(CH3)2C2H5H3CHClH2OC2H5OHIon-pair Mechanism(離子對(duì)機(jī)理離子對(duì)機(jī)理) RLR+L-R+ L-R+ + L-Close ion-

7、pair loose ion-pair free ions(緊密離子對(duì)緊密離子對(duì)) (松散離子對(duì)松散離子對(duì)) (自由離子自由離子)Energy DiagramR3CXSide ReactionRearrangement and E18.2.1.2 Factors affecting SN1 and SN2 The structures of alkyl groups (烴基的結(jié)構(gòu)烴基的結(jié)構(gòu)) Leaving groups (離去基團(tuán)離去基團(tuán)) The nucleophile (親核試劑親核試劑) The solvent (溶劑溶劑)8.2.1.2.1 The structures of alk

8、yl groups0(CH3)3CX3 0.00001(CH3)3CCH2XNeopentyl0.02(CH3)2CHX2 1CH3CH2X1 30CH3XMethylRelative RateCompoundSubstituentSteric effectSN2SN11,200,000(CH3)3COH3 (CH3)3CBr12(CH3)2CHOH2 (CH3)2CHBr1.0CH3CH2OH1 CH3CH2Br1.0CH3OHMethylCH3BrRelative rateProductTypeAlkyl halideStability of the carbocationsSN1反應(yīng)速度

9、反應(yīng)速度: PhCH2X , CH2=CHCH2X 3RX 2RX 1RX CH3X CH2=CHX, PhX(CH3)3CCH2Cl為何既難以發(fā)生為何既難以發(fā)生SN2又難以發(fā)生又難以發(fā)生SN1?OCH3BrONaCH3ONa+CH3Br SN2SN2反應(yīng)速度反應(yīng)速度: PhCH2X, CH2=CHCH2X CH3X 1RX 2RX 3RX CH2=CHX, PhX對(duì)于對(duì)于芐基鹵、烯丙基鹵芐基鹵、烯丙基鹵， SN1和和SN2均容易發(fā)生；對(duì)于均容易發(fā)生；對(duì)于乙烯型鹵、芳基鹵乙烯型鹵、芳基鹵，SN1和和SN2均難以發(fā)生；使用非常強(qiáng)的堿，如均難以發(fā)生；使用非常強(qiáng)的堿，如NaNH2，將使其發(fā)生消除反應(yīng)

10、，分別，將使其發(fā)生消除反應(yīng)，分別得到炔烴、苯炔得到炔烴、苯炔(會(huì)進(jìn)一步發(fā)生加成會(huì)進(jìn)一步發(fā)生加成)?8.2.1.2.2 Leaving groupsGood L(好的離去基團(tuán)好的離去基團(tuán))離去基團(tuán)對(duì)離去基團(tuán)對(duì)SN2和和SN1具有類(lèi)似的影響，但對(duì)具有類(lèi)似的影響，但對(duì)SN1影響程度更大影響程度更大Weakly basic(堿性弱堿性弱)HL Strong acid(強(qiáng)酸強(qiáng)酸)Stable(穩(wěn)定穩(wěn)定)-I -Br -Cl -F離去能力離去能力 其它常見(jiàn)的離去基團(tuán)其它常見(jiàn)的離去基團(tuán) -OTsOSOOCH3對(duì)甲基苯磺酸酯基對(duì)甲基苯磺酸酯基-OSO2C6H4CH3-p-OMsOSCH3OO甲基磺酸酯基甲基磺

11、酸酯基-ONsOSOONO2對(duì)硝基苯磺酸酯基對(duì)硝基苯磺酸酯基-OSO2C6H4NO2-pSOOOOR-OSO2OR烷基硫酸酯基烷基硫酸酯基N NOH2OR2NR30120010,00030,00060,000Relative reactivityHO, H2N, ROFClBrITsOLeaving group離去基團(tuán)的離去順序：離去基團(tuán)的離去順序：-N+N -O+R2 -OSO2C6H4NO2-p -OSO2Ph -OSO2C6H4CH3-p -OSO2CH3 -I -O+H2 -Br -Cl H3C OSOCH3OOROH堿CH3OR硫酸二甲酯硫酸二甲酯是個(gè)很好的是個(gè)很好的甲基化甲基化試劑

12、，試劑，常用于和醇反應(yīng)得到常用于和醇反應(yīng)得到甲基醚甲基醚R OSOOCH3CN-RCNOSO2GC2H5OHOC2H5SN1G = OCH3 CH3 H Cl NO2速率速率 1.0 1.6 3.1 8.4 558.2.1.2.3 The nucleophile試劑的親核性對(duì)試劑的親核性對(duì)SN1的反應(yīng)速率影響很小，對(duì)的反應(yīng)速率影響很小，對(duì)SN2影響很大影響很大 1)Nucleophilicity and basicityBasicity(堿性堿性): the affinity of a base for a proton (與質(zhì)子的結(jié)合能力與質(zhì)子的結(jié)合能力)Nucleophilicity(親核

13、性親核性): the affinity of a Lewis base for a carbon atom (與碳與碳原子的結(jié)合能力原子的結(jié)合能力)親核性親核性除與除與堿性堿性有關(guān)外，還與有關(guān)外，還與可極化度可極化度 (Polarizability) 有關(guān)有關(guān)Polarizability (可極化度可極化度): the ease with which the electron distribution around an atom is distorted by a nearby electric field(核外電子分布受外界電場(chǎng)影響而核外電子分布受外界電場(chǎng)影響而發(fā)生扭曲變形發(fā)生扭曲變形)L

14、arger atoms are more polarizable. I Br Cl FS O質(zhì)子溶劑中親核性質(zhì)子溶劑中親核性 I-F-：1)可極化度可極化度; 2)溶劑化效應(yīng)溶劑化效應(yīng) a. In a group of nucleophiles in which the nucleophilic atom is the same, nucleophilicities parallel basicities (試劑中親核原子相同時(shí)，親核性與堿性一致試劑中親核原子相同時(shí)，親核性與堿性一致).RO- HO- ArO- RCOO- ROH H2Ob. Nucleophilicity decrease

15、to the right in an row of the peridoic table (同一周期同一周期中親核性自左向右逐漸降低，與堿性一致中親核性自左向右逐漸降低，與堿性一致).NH2- OH- F- R3C- R2N- RO- F-c. Nucleophilicity usually increases in going down a column of the periodic table (同一主族自上而下親核性增強(qiáng)，與堿性相反同一主族自上而下親核性增強(qiáng)，與堿性相反)(在在質(zhì)子溶劑質(zhì)子溶劑中中). F- Cl- Br- I- HO- HS- RO- CN I NH3 NR3 RO-

16、 HO N3 Br ArO CH3COO Cl H2O F In aqueous ethanolNu-CH3BrNuCH3Br-+17001,00016,00025,000100,000125,000125,000Relative reactivityH2ONH3ClHOCH3OICNHSNuSN2Polar aprotic solvents(偶極溶劑偶極溶劑, 極性非質(zhì)子溶劑極性非質(zhì)子溶劑) COHNCH3CH3SOCH3CH3DMF DMSO “Naked” anions are highly reactive both as bases and nucleophiles (裸露的負(fù)離子具

17、有很強(qiáng)的親核裸露的負(fù)離子具有很強(qiáng)的親核性和堿性性和堿性). 在在偶極溶劑偶極溶劑中親核性順序中親核性順序: F- Cl- Br- I- (與堿性順序一致與堿性順序一致)對(duì)對(duì)SN2反應(yīng)，偶極溶劑比質(zhì)子溶劑有利反應(yīng)，偶極溶劑比質(zhì)子溶劑有利 N3 CH3CH2CH2CH2BrCH3CH2CH2CH2N3Br +Solvent6.61,3002,8005,000200,000Relative reactivityH2ODMSODMFCH3CNHMPASolvent3) Sterically hindered nucleophiles are poor ones (位阻大的試劑親核性差位阻大的試劑親核性

18、差)親核性順序：親核性順序：CH3O- CH3CH2O- (CH3)2CHO- (CH3)3CO- (與堿性順序相反與堿性順序相反)very easyvery difficultSN2CH3O-(CH3)3CO-8.2.1.2.4 The solvent effects(溶劑效應(yīng)溶劑效應(yīng))溶劑對(duì)溶劑對(duì)SN2和和SN1均有影響，但對(duì)均有影響，但對(duì)SN1影響程度更大影響程度更大SN1R LR LR+ L-+ -Polar protic solvent will greatly increase the rate of ionization of an alkyl halide in the abo

19、ve SN1 reaction(對(duì)于對(duì)于中性底物中性底物, 溶劑極性溶劑極性增強(qiáng)增強(qiáng), 使使SN1反應(yīng)速度反應(yīng)速度顯著加快顯著加快). +t-BuBrSol-OHt-BuO-SolHBr1450Water29Ethanol / water (50%:50%)10Ethanol / water (80%:20%)1EthanolRelative rateSolventR LR LR+ L+ +對(duì)于對(duì)于帶正電的底物，帶正電的底物，溶劑極性溶劑極性增強(qiáng)，增強(qiáng)，將使將使SN1速率速率有所降低有所降低 0.32Water0.62Ethanol / water (80%:20%)1EthanolRelat

20、ive rateSolventSN2R LR LL-Nu-+Nu-RNu溶劑極性溶劑極性增強(qiáng)增強(qiáng)，常使，常使SN2速率速率有所降低有所降低 R LR LL-+-Nu:+NuRNu+溶劑極性溶劑極性增強(qiáng)增強(qiáng)，將使，將使這類(lèi)這類(lèi)SN2速率速率顯著加快顯著加快 R3N: + R XR4NX-Nu-R L+R L+-NuL+RNu溶劑極性溶劑極性增強(qiáng)增強(qiáng)，將使，將使這類(lèi)這類(lèi)SN2速率速率顯著降低顯著降低 +Nu:RNu+R L+R L+NuL+溶劑極性溶劑極性增強(qiáng)增強(qiáng)，使，使這類(lèi)這類(lèi)SN2速率速率有所降低有所降低 R+R XAg+R X AgAgXNO2-親核性強(qiáng)親核性強(qiáng) 易與正離子結(jié)合易與正離子結(jié)合

21、 SN1 versus SN21）一鹵甲烷，伯鹵代烷一鹵甲烷，伯鹵代烷容易發(fā)生容易發(fā)生SN2，叔鹵代烷叔鹵代烷容易發(fā)生容易發(fā)生SN1，仲鹵代烷仲鹵代烷可以可以發(fā)生發(fā)生SN2 或或SN1。烯丙型鹵、芐基鹵烯丙型鹵、芐基鹵容易發(fā)生親核取代，容易發(fā)生親核取代，乙烯型鹵、芳基鹵乙烯型鹵、芳基鹵不不易發(fā)生親核取代易發(fā)生親核取代2）Ag+(常用常用硝酸銀硝酸銀或或氰化銀氰化銀)的作用：促使的作用：促使SN1反應(yīng)發(fā)生反應(yīng)發(fā)生3）兩位負(fù)離子）兩位負(fù)離子(Ambident anion)：4）I-既是一個(gè)好的離去基團(tuán)又是一個(gè)好的親核試劑既是一個(gè)好的離去基團(tuán)又是一個(gè)好的親核試劑5）強(qiáng)）強(qiáng)的的親核試劑親核試劑有利于有

22、利于SN27）溶劑）溶劑的影響的影響6）好）好的的離去基團(tuán)離去基團(tuán)對(duì)對(duì)SN1及及SN2均有利均有利 (對(duì)對(duì)SN1更有利更有利)質(zhì)子溶劑質(zhì)子溶劑的的極性增強(qiáng)極性增強(qiáng)(即即酸性增強(qiáng)酸性增強(qiáng))有利于常見(jiàn)的有利于常見(jiàn)的SN1質(zhì)子溶劑質(zhì)子溶劑的的極性增強(qiáng)極性增強(qiáng)(即即酸性增強(qiáng)酸性增強(qiáng))不利于不利于常見(jiàn)的常見(jiàn)的SN2偶極溶劑偶極溶劑有利于有利于SN28.2.2 Elimination (消除反應(yīng)消除反應(yīng))E1 and E2CCXHB -B H-X CCC CHXBTransition stateE2C CHXC CHslowE1B:CCfastBrH3CH3CCH3CH2C2H5OHheat+CH2CH3

23、H3CH2CCH3CH3H3CHSN versus E1) 伯鹵代烷伯鹵代烷碳上無(wú)支鏈碳上無(wú)支鏈時(shí)主要發(fā)生時(shí)主要發(fā)生SN2,但是當(dāng)使用但是當(dāng)使用非常強(qiáng)的堿非常強(qiáng)的堿(如如NH2)時(shí)則主時(shí)則主要發(fā)生要發(fā)生E2碳上碳上有有支鏈支鏈時(shí)主要發(fā)生時(shí)主要發(fā)生E2 使用大體積的強(qiáng)堿使用大體積的強(qiáng)堿(如如t-BuO )時(shí)時(shí)主要發(fā)生主要發(fā)生E22)叔鹵代烷叔鹵代烷堿性條件堿性條件下主要發(fā)生下主要發(fā)生E1；溶劑解溶劑解(如如水解，醇解水解，醇解)時(shí)主要發(fā)生時(shí)主要發(fā)生SN13) 仲鹵代烷仲鹵代烷弱堿性的強(qiáng)親核試劑弱堿性的強(qiáng)親核試劑(如如I, CN, SH, NO2, RCO2)有利于有利于SN2強(qiáng)堿強(qiáng)堿(如如RO)

24、有利于有利于E2; 體積越大體積越大, 堿性越強(qiáng)堿性越強(qiáng)越有利于越有利于E2碳碳上有支鏈上有支鏈，有利于，有利于E2溶劑解溶劑解(如如水解，醇解水解，醇解)時(shí)可以發(fā)生時(shí)可以發(fā)生SN1/E14) 升溫升溫有利于有利于E5) 偶極溶劑偶極溶劑有利于有利于SN2, 極性溶劑極性溶劑有利于有利于SN1KOBu-tt-BuOH, 40CCH3(CH2)17OC(CH3)3CH3(CH2)15CH=CH2+CH3(CH2)17BrCH3CHCH2BrNaOC2H5CH3C=CH2CH3CHCH2OC2H5+C2H5OH,55CH3CH3CH3CH3CH2CH2CH2BrNaOC2H5CH3CH2CH=CH

25、2CH3(CH2)3OC2H5+C2H5OH,5560% 40%13% 87%9% 91%H3CCClCH3CH380% C2H5OH20% H2O25 oCH3CCOHCH3CH3+ H3CCOCH2CH3CH3CH3CCH3CH3H2C(83%)(17%)CH3CCH3BrC2H5OH / C2H5 Na 25oCH2CCHCH3+CH39%91%CH3CCH3OCH3C2H5H2CCCH3CH3(100%)C2H5OH / C2H5 Na55oCCH3CCH3BrCH3CH3CHCH3BrC2H5OH / C2H5 Na55oCCH3CHCH3OC2H5H2CCHCH3+(21%) (7

26、9%)CH3CH(CH2)5CH3ClKCNDMSOCH3CH(CH2)5CH3CN(70%)+HC CNat-BuBrHC CBu-tCH3BrNaCNCH3CH2ONaBrC(CH3)3CH2BrNaOC(CH3)3+ CH2OC(CH3)3INaN3N3(75%)CH3CHCHCH3CH3NaOAcCH3CHCH=CH2CH3BrCH3COCH3CH3CHCHCH3CH3OCOCH3CH3C=CHCH3CH3+(11%)(89%)OCH2CH3t-BuOMe?8.2.3 Neighboring-group Participation (鄰基參與鄰基參與)CH3CHCOO-Br*濃NaOH

27、CH3CHCOO-OH*CH3CHCOO-Br*稀NaOH / Ag2OCH3CHCOO-OH*構(gòu)型翻轉(zhuǎn)構(gòu)型翻轉(zhuǎn) SN2 構(gòu)型保持構(gòu)型保持構(gòu)型翻轉(zhuǎn)構(gòu)型翻轉(zhuǎn) OH-CCOOHOH3CH構(gòu)型再次翻轉(zhuǎn)構(gòu)型再次翻轉(zhuǎn) 鄰基參與鄰基參與促進(jìn)離去基團(tuán)的離去，反應(yīng)速度促進(jìn)離去基團(tuán)的離去，反應(yīng)速度顯著加快顯著加快參與基團(tuán)參與基團(tuán)常帶有常帶有孤對(duì)電子或孤對(duì)電子或電子電子ClH2OOHThe reaction is 3200 times faster!SH2OSOH2mustard gas (芥子氣芥子氣)SClClbis(2-chloroethyl)sulfaneCH3BrHCH3HOHHBrCH3BrHCH3H

28、BrCH3HBrCH3BrH+蘇式蘇式蘇式外消旋體蘇式外消旋體BrOHH3CCH3HHH+BrOH2H3CCH3HHBrH3CCH3HHBr-BrBrH3CCH3HHBrBrCH3H3CHH+赤式赤式赤式內(nèi)消旋體赤式內(nèi)消旋體CH3PhHCH3TsOHHOAcCH3PhHCH3AcOH赤式赤式赤式赤式(構(gòu)型保持構(gòu)型保持)CH3PhHCH3HOTsHOAc?8.2.4 Reduction (還原還原)R XHR H1) LiAlH4RI RBr RCl RFCH3X 1 2 3 (主要發(fā)生消除主要發(fā)生消除) 乙烯基鹵乙烯基鹵, 芳基鹵芳基鹵也可被還原也可被還原氫化鋁鋰氫化鋁鋰還原性強(qiáng)還原性強(qiáng), 可

29、還原可還原醛醛, 酮酮, 酰氯酰氯, 酸酐酸酐, 羧酸羧酸, 羧酸酯羧酸酯得到得到醇醇; 還原還原酰胺酰胺, 腈腈,脂肪族硝基化合物脂肪族硝基化合物得到得到胺胺; 還原還原炔炔得到得到烯烯2) NaBH4硼氫化鈉硼氫化鈉活性不如氫化鋁鋰活性不如氫化鋁鋰, 可在水可在水, 醇中使用。可還原醇中使用?？蛇€原醛醛, 酮酮, 酰氯酰氯得到得到醇醇3) Metal (Sn, Zn, Fe) and acid 可還原可還原鹵代烴，鹵代烴，還可還原還可還原硝基化合物硝基化合物, 腈腈, 得到得到胺胺CH3CHCH2CH2CH3BrZnHClCH3CHCH2CH2CH3H4) HI 5) Catalytic

30、hydrogenolysis(催化氫解催化氫解)CH2ClH2 / PdCH3可對(duì)可對(duì)活潑鹵代烴活潑鹵代烴, 如如芐基鹵芐基鹵, 烯丙基鹵烯丙基鹵進(jìn)行氫解。還可還原進(jìn)行氫解。還可還原酰氯酰氯, 羧酸酯羧酸酯, 醛醛, 酮酮得到得到醇醇; 還原還原酰胺酰胺, 腈腈, 脂肪族硝基化合物脂肪族硝基化合物得到得到胺胺; 還原還原炔炔, 烯烯得到得到烷烷; 還原還原苯苯得得到到環(huán)己烷環(huán)己烷6) Na / NH3(l)C CHClRRNa / NH3(l)C CHHRR雙鍵構(gòu)型不變雙鍵構(gòu)型不變還可還原還可還原炔炔得到得到烯烯; 對(duì)對(duì)苯環(huán)苯環(huán)進(jìn)行進(jìn)行Birch還原還原8.3 Preparation8.3.1

31、 Halogenation of hydocarbons (烴的鹵化烴的鹵化)CH4Cl2hCH3ClCl2hClBr2hCH3CH3BrNBSBrCH3Cl2 / FeCH3ClCH3Cl+8.3.2 Addition of halogens or hydrogen halides to alkenes or alkynes (鹵素或鹵化氫對(duì)烯或炔的加成鹵素或鹵化氫對(duì)烯或炔的加成)8.3.3 Preparation from alcohols(由醇制備由醇制備)HX (NaX / H2SO4) PX3 PX5 SOCl28.3.4 Preparation from other alkyl h

32、alides (由其它鹵代烷制備由其它鹵代烷制備)8.3.5 Preparation from carbonyl compounds(由羰基化合物制備由羰基化合物制備)COPCl505CClCl機(jī)理機(jī)理PCl505OClCl8.3.6 Preparation via haloform reaction(由鹵仿反應(yīng)制備由鹵仿反應(yīng)制備)MechanismIodoform reaction:Acid-catalysed halogenation can be made to stop after one halogen is introduced if only one equivalent of

33、halogen is used. They invented a tool to make carbon-carbon bonds in organic chemistry The tool is called palladium-catalyzed cross-coupling It has applications in a range of fields from medicine to electronicsThe Nobel Prize in Chemistry 2010 was awarded jointly to Richard F. Heck, Ei-ichi Negishi

34、and Akira Suzuki for palladium-catalyzed cross couplings in organic synthesis. Organometallic Compounds(有機(jī)金屬化合物有機(jī)金屬化合物)CM bond CNa and CK bonds are largely ionic in character.CPb, CSn, CTl, and CHg bonds are essentially covalent.CLi and CMg bonds lie in between these two extremes.strong base powerfu

35、l nucleophile8.4 Organicmetallic NomenclatureThe metal is the parentTetramethyllead四乙基鉛四乙基鉛Methyllithium甲基鋰甲基鋰Diethylmagnesium二乙基鎂二乙基鎂Ethynylsodium乙炔乙炔(基基)鈉鈉LiMethylmagnesium iodide Diethylaluminum chloride碘化甲基鎂碘化甲基鎂 氯化二乙基鋁氯化二乙基鋁 Cyclopropyllithium環(huán)丙基鋰環(huán)丙基鋰CH3MgI (CH3CH2)2AlCl(CH3)4Si(CH3)3B(CH3)3SnC

36、2H5tetramethylsilaneTMStrimethylboraneethyltrimethylstannane四甲基硅烷四甲基硅烷 三甲基硼烷三甲基硼烷 三甲基乙基錫烷三甲基乙基錫烷8.5 Preparation8.5.1 Via reaction of organic halides with metals (通過(guò)鹵代烴與金通過(guò)鹵代烴與金屬反應(yīng)屬反應(yīng)) Ether(醚醚)：乙醚：乙醚 四氫呋喃四氫呋喃(THF)O8.5.2 Via reaction of organometallics with salts (通過(guò)有機(jī)金屬與無(wú)通過(guò)有機(jī)金屬與無(wú)機(jī)鹽反應(yīng)機(jī)鹽反應(yīng)) RMetherRM+

37、MXMX金屬的電正性越強(qiáng)，鹵素的電負(fù)性越強(qiáng)，二者越易成鹽金屬的電正性越強(qiáng)，鹵素的電負(fù)性越強(qiáng)，二者越易成鹽電正性電正性:Li+ Mg2+ Al3+ Si+4 Zn2+ Cd2+ H+ Sn2+ Cu+ Hg2+RMgCl + CdCl2R2CdMgCl2+Et2Hg +ZnCl2 RMgCl +AlCl3R3AlMgCl2+8.5.3 Via reaction of organometallics with hydrocarbons (通過(guò)有機(jī)通過(guò)有機(jī)金屬與烴反應(yīng)金屬與烴反應(yīng)) +C2H5NaPhHC2H6PhNa+PhMgBrHC CHPhHHC CMgBr8.6 Organomagnesiu

38、m Reagents Grignard Reagents (有機(jī)鎂試有機(jī)鎂試劑劑格氏試劑格氏試劑) Francois Auguste Victor Grignard(1871 - 1935) the Nobel Prize for Chemistry in 1912His work in organomagnesium compounds opened a broad area of organic synthesis. 8.6.1 Preparation of Grignard reagentsRX + MgetherRMgXMgXC6H5RORROR Reactivity of halid

39、es: RI RBr RCl乙烯型鹵，芳基鹵乙烯型鹵，芳基鹵活性不如活性不如鹵代烷鹵代烷 35 oCCH3I+ MgEt2OCH3MgI (95%)ClMg / Et2OMgCl (96%)35 oCCH2CH2ClMg / THFCH2CH2MgCl(92%)60 oCBrMg / Et2OClFMgBrClF8.6.2 Reactions of Grignard reagents8.6.2.1 As bases Grignard reagents with acidic hydrogens (格氏試劑格氏試劑作為堿與酸性氫的反應(yīng)作為堿與酸性氫的反應(yīng)) HX RSO3H RCOOH H2S

40、H2O RSH ROH RCCH NH3 RNH2 RCONH2+PhMgBrHC CHPhHHC CMgBrR MgX + H-OHRHMg(OH)X+R MgX + D2ORDMg(OD)X+8.6.2.1 Grignard reagents as nucleophiles(格氏試劑作為親核試劑格氏試劑作為親核試劑的反應(yīng)的反應(yīng)) 1)與與二氧化碳二氧化碳反應(yīng)反應(yīng)R MgX + O=C=ORCOOMgXH2ORCOOH2)與與活潑鹵代烴活潑鹵代烴偶聯(lián)偶聯(lián)R MgX + RXR-R+PhCH2XR CH2PhRMgX+MgClClCH3CCMgI(CH3)3CBr+C CH2H3CH3CRX應(yīng)

41、為應(yīng)為伯鹵代烷伯鹵代烷, 芐基鹵芐基鹵, 烯丙基鹵烯丙基鹵3)其他底物其他底物RMgXO+ROMgXH+ / H2OROH+H3O+C6H5MgBr(90%)HCHOOMgBrC6H5CH2Et2OC6H5CH2OHHOCH2CH2CCH3OCH3MgBr2 CH4BrMgOCH2CH2CCH3CH3OMgBrH2OHOCH2CH2CCH3CH3OH2 NH4ClCH2CH3CC6H5OHCH3CH23-Phenyl-3-pentanolC6H5MgBrCH2CH3COCH3CH2+1. Et2O2. NH4ClCH2CH3CC6H5OHCH3CH2H2OCH3CH2MgBr+C6H5CCH3

42、CH2O1. Et2O2. NH4ClH2OCH2CH3CC6H5OHCH3CH2CHH2CO+H+C6H5MgBrC6H5CH2CHOMgBrEt2OC6H5CH2CHOHCH3CH3CH3RMgX +OROMgXROHRMgX +H+ / H2ORCNC NMgXRRC NHRRC ORR堿性堿性條件下條件下環(huán)氧化合物環(huán)氧化合物開(kāi)環(huán)為開(kāi)環(huán)為SN210 oCEt2OCH3CH2CH2CH2Li + LiBrCH3CH2CH2CH2Br + 2 Li80-90%8.7 Organolithium Compounds (有機(jī)鋰有機(jī)鋰) CH3CH2CCH3BrLiCH3CH2CCH3LiLiBr

43、Li+n-BuLiBrLin-BuBr+n-BuLiCH2ClCH2Lin-BuCl反應(yīng)：有機(jī)鋰類(lèi)似格氏試劑，但活性更高反應(yīng)：有機(jī)鋰類(lèi)似格氏試劑，但活性更高8.8 Organocopper Reagents Lithium Dialkylcuperates (R2CuLi)(有機(jī)銅試劑有機(jī)銅試劑二烴基銅鋰二烴基銅鋰)8.8.1 Preparation of R2CuLi2+ CuIR2CuLiLiI+RLi8.8.2 Reaction of R2CuLi: Coupling with Alkyl Halo(與鹵代烴偶聯(lián)與鹵代烴偶聯(lián))R2CuLi + RXRRRCuLiX+BrCH3+ (CH3

44、)2CuLi(75 %)Et2OBrBr(CH3)2CuLi+CH3CH3乙烯基鹵，芳基鹵乙烯基鹵，芳基鹵亦可順利與二烴基銅鋰反應(yīng)亦可順利與二烴基銅鋰反應(yīng)(CH3CH2CH2CH2)2CuLi + IH3CH2CH2CH2C(75 %)Et2O+(CH3CH2CH2CH2)2CuLiBrEt2OCH2CH2CH2CH3(80%)Br(CH2=C)2CuLiCH3+C=CH2CH3+SO3CH2CH2CH2CH3H3C(C6H5)2CuLiCH2CH2CH2CH3鏈狀仲鹵代烷，叔鹵代烷鏈狀仲鹵代烷，叔鹵代烷可能發(fā)生可能發(fā)生消除消除羥基，羧基，羰基羥基，羧基，羰基不受影響不受影響(CH3)2CuL

45、iIOHCH3OH+PhBrHHn-Bu2CuLiPhBu-nHH乙烯基鹵乙烯基鹵的的雙鍵構(gòu)型雙鍵構(gòu)型不改變不改變8.9 Organozinc Reagents (有機(jī)鋅試劑有機(jī)鋅試劑)Simmons-Smith reaction CH2I2Zn-Cu / etherICH2ZnIC CICH2ZnIH2CIZnICH2C CHHICH2ZnICH2HHICH2ZnICH2HHC CHHstereospecificCH2I2, Zn-Cu / ether(79%)CH2I2, Zn-Cu / ether(55%)8.10 Organosodium Reagents (有機(jī)鈉試劑有機(jī)鈉試劑)Wr

46、tz反應(yīng)反應(yīng)an antifungal(抗真菌的抗真菌的) compound isolated from lily plants3-甲基甲基-1,5-二甲氧基二甲氧基-2,4-二氯苯二氯苯2,4-dichloro-1,5-dimethoxy-3-methylbenzeneChlortetracycline氯四環(huán)素氯四環(huán)素Thyroxine甲狀腺素甲狀腺素Aryl Halides(芳基鹵，鹵代芳烴芳基鹵，鹵代芳烴)8.11 StructureXX8.12 PreparationHalogenation of arenes(芳烴的鹵化芳烴的鹵化) Br2 / FeO2NO2NBr(85%)Halo

47、genation of aryl diazonium salts (重氮鹽的鹵化重氮鹽的鹵化)ArNH2NaNO2, H3O+-H2ON NArXAr1) NaNO2, H3O+ClNH22) CuBrClBr(62%)SN1CuCl CuBrKINaBF48.13 Reactions8.13.2 Formation of Organometallic Reagents (有機(jī)金屬試劑有機(jī)金屬試劑)35 oCC6H5Br + MgEt2OC6H5MgBrMg / THFClMgClLi / Et2OClLi8.13.1 Electrophilic aromatic substitution(芳香族親電取代芳香族親電取代) Br(CH3CO)2OAlCl3BrCH3CO(69-79%)Wrtz-Fittig反應(yīng)反應(yīng)Brn-C5H11