第十七章 胺、重氮和偶氮化合物

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肟的还原——
O CH3(CH2)6CCH3 NOH CH3(CH2)6CCH3 NH2 CH3(CH2)6CHCH3 62%~69%
NH2OH
Na, EtOH
NH2 NOH H2, Raney-Ni CH3CH2CH2CHCH3 CH3CH2CH2CCH3 EtOH 85%
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60 82º
59 34º
59 3º
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11.3 Basicity of Amines ：
RNH2 碱 RNH2 RNH3+Cl-
H2O
RNH3+ 共轭酸
OH-
HCl NaOH
RNH3+ClRNH2 H2O NaCl
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气相中测定的碱性强弱次序为：
(C2H5)3N (C2H5)2NH C2H5NH2 NH3， 水溶液中测定的碱性强弱次序为： (C2H5)2NH (C2H5)3N C2H5NH2 NH3， 烷基给电子和氢键的共同作用结果
NO2
1. Fe, HCl, H2O 2. OH-
NH2 97%
NH2 Zn, HCl CH3
NO2 SnCl2, HCl CHO
NH2
CHO
常用的还原剂：锡、铁、锌、氯化亚锡等
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NO2 CH(CH3)2 H2, Raney-Ni MeOH
NH2 CH(CH3)2
92%
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第10章 胺及含氮化合物
Chapter 10 Amines & Other Nitrogen Compounds
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Natural Nitrogen Compounds
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10.1 Nomenclature and Structure of Amines Common Names：
N
H
5o
H
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NH2 碱性（pKa)： OCH3 >
NH2 >
NH2
3
NH3
NH3
NH3
NH3
OMe
OMe
OMe 负电荷有利于 稳定铵正离子
OMe
Strong bases have weak conjugate acids, and weak bases have strong conjugate acids.
N N DBN N DBU
N
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11.4 Acidity of Amines
B-
R NH2
R NH
HB
pKa ~36
CH3 (CH3CHCH2)2NH n-BuLi
氨基离子
CH3 (CH3CHCH2)2NLi 二异丙基氨基锂 （LDA） n-BuH pKa >50
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CH2CH3 N CH3 H
8
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N N CH3 CH3 CH3
N N CH3
(+)-Trö ger base 特勒格尔
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(-)-Trö ger base
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C2H5
CH3 I + N C H 6 5 CH2CH CH2
CH3 I +N C6H5 C2H5 CH2 CHCH2 -
CH3CH2CH3
44 -42º
CH3CH2OH
46 78.5º
CH3CH2NH2
45 16.6º
CH3(CH2)2OH
CH3(CH2)2NH2
CH3CH2NHCH3
(CH3)3CH
(CH3)2CHOH
(CH3)2CHNH2
(CH3)3N
58 -0.5º
60 97º
59 48º
59 37º
58 -12º
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烷基的给电子作用 氢键的作用
H O H C2H5 N H H H O H
+
H H H O H O H C2H5 N H C2H5
+
H C2H5 H O H C2H5 N H C2H5
+
H O H
氢键的生成使铵离子更加稳定，从而使碱性增强。
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胺
pKa （25oC, H2O） 9.24 10.62 10.73 9.79 10.64 10.94 10.75
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H
pm 0.8 0 1 107.3o
N H H H 3C
m N .4p 7 14 112.9o
H
5.9 10
o
H H 3C
N pm 7 14 108o CH3
CH3
氨的结构
甲胺的结构
三甲胺的结构
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N
H
5o
H
142 .
H3CH2C N H3C H
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Important Reagent Bases
Base Name Pyridine Triethyl Amine Hü nig's Base DBU Barton's Base Potassium t-Butoxide Sodium HMDS LDA
Formula
(C2H5)3N 5.3 10.7 11.4 12 14
4-(N, N-二甲氨基)苯甲酸
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3-甲基-5-氨基-1-戊醇
4
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胺类化合物形成铵盐或季铵盐后，命名如下例：
CH3NH2 HCl (C6H5NH2)2 H2SO4 (CH3CH2)4NBr
甲胺盐酸盐 Methylammonium chloride
CH3 N CH2CH3 Cl H
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NH2 碱性（pKa)： >
NH2 > NO2
NH2
NO2
4.58
2.47
1.00
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pKa = 13.6
Here, resonance stabilization of the base is small, due to charge separation, while the conjugate acid is stabilized strongly by charge delocalization. Consequently, aqueous solutions of guanidine are nearly as basic as are solutions of sodium hydroxide.
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Gabriel合成法——
O NH O KOH O N-K+ O RX O N R O H2NNH2 NaOH H2O CO2-Na+ + CO2-Na+ O NH NH O + RNH2 RNH2
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O N- K+ R OH TsCl R OTs SN2 O O N R O NH2NH2 R NH2
O N-K+ C6H5 H OH CH3 (R) TsCl Py C6H5 H OTs CH3 (R) O SN2 构型翻转 (S) O C6H5 N H CH3 O NH2NH2
C6H5 H2N H CH3 (S)
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硝基的还原—— Reduction of Nitro Groups
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Compound
C6H5SO2NH2
pKa
33
27
19
15
10
9.6
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11.5 Preparation of Amines Preparation of 1º -Amines
Example 1. 2. Nitrogen Reactant N3(–) C6H5SO2NH(–) Carbon Reactant RCH2-X or R2CH-X RCH2-X or R2CH-X RCH2-X or R2CH-X RCH=O or R2C=O RCOX R3C(+) 1st Reaction Type SN2 SN2 Initial Product RCH2-N3 or R2CH-N3 RCH2-NHSO2C6H5 or R2CH-NHSO2C6H5 RCH2-CN or R2CH-CN RCH=NH or R2C=NH RCO-NH2 R3C-NHCONH2 2nd Reaction Conditions LiAlH4 or 4 H2 & Pd Na in NH3 (liq) 2nd Reaction Type Hydrogenolysis Hydrogenolysis Final Product RCH2-NH2 or R2CH-NH2 RCH2-NH2 or R2CH-NH2 RCH2-CH2NH2 or R2CH-CH2NH2 RCH2-NH2 or R2CH-NH2 RCH2-NH2 R3C-NH2
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Hofmann Rearrangement and Curtius Reaction
RCONH2 NaOH, Br2 RNCO H2O RNH2
O R C
H NH
-OH
H2O
OR C NH
X X X-
O R C
-OH H N X H O 2
OR C N X a b a O R C
CH3CH2NH2 (CH3CH2)2NH NH2 CH3NCH2CH3 CH2CH2CH3
乙胺 ethanamine
二乙胺 diethylamine
苯胺 aniline
甲（基）乙（基）丙胺 Nethylmethylpropanamine
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系统命名法：
选择含氮的最长碳链为母体，称为“某胺”，氮上的其它烃 基则作为取代基，在其前面加上N-，以明确取代基的位置。
（S)
(R)
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10.2 Boiling Point and Water Solubility
Compound
Mol.Wt. Boiling Point º C C Mw. Bp
CH3(CH2)2CH3
CH3CH3
30 -88.6º
CH3OH
32 65º
CH3NH2
31 -6.0º
胺
pKa （25oC, H2O） 9.34 4.60 1.20 4.40 -0.26 2.47 1.00
NH3 CH3NH2 (CH3)2NH (CH3)3N CH3CH2NH2 (CH3CH2)2NH (CH3CH2)3N
C6H5CH2NH2 C6H5NH2 (C6H5)2NH C6H5NHCH3 o-NO2-C6H4NH2 m-NO2-C6H4NH2 p-NO2-C6H4NH2
苯胺硫酸盐 Aniline sulfate
溴化四乙铵 Tetraethylammonium bromide
C6H5CH2N(CH2CH3)3Br
N-甲基-N-乙基环戊烷基铵盐酸盐 N-Ethyl-N-methylcyclopentylammonium chloride
溴化三乙基苄基铵 Benzyltriethylammonium bromide
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Curtius Reaction
O R C O R C N
R COCl
NaN3
N N N
-N2
RNCO
H2O -CO2
RNH2
酰基氮烯
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CH3O N CH3 CH3 CH3 CH3CH2NHCH2CH2CHCH2CH3
N, N-二甲基-4-甲氧基苯胺
3-甲基-N-乙基戊胺
结构比较复杂的胺和含有多官能团的化合物，也可以把烃 或其它官能团作为母体，氨基作为取代基来命名。
HO2C N CH3 CH3 CH3 NH2CH2CH2CHCH2CH2OH
3.
4. 5. 6.
CN(–)
NH3 NH3 NH2CONH2 (urea)
SN2
Addition / Elimination Addition / Elimination SN1
LiAlH4
H2 & Ni or NaBH3CN LiAlH4 NaOH soln.
Reduction
Reduction Reduction Hydrolysis
b O CO2 RNH2 HO C NH R OH -O C N R OH-
O=C=N R
异氰酸酯
N
酰基氮烯
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在Hofmann 重排反应中，如果发生迁移的烃基碳原 子为手性碳，迁移时其构型保持。
H C6H5CH2 C CONH Br2, NaOH, H2O 2 CH3 H C6H5CH2 C NH 2 CH3
(CH3)3CO(–) K(+)
[(CH3)3Si]2N(–) Na(+)
[(CH3)2CH]2N(–) Li(+)
pKa
19
26
35.7
pKa 6.79 pKa 8.8
pKa 12
pKa 12.3
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问题11-8 DBN和DBU比一般胺的碱性强得多，是有机 合成中广泛使用的有机碱，试指出DBN和DBU分子中哪 一个氮原子最容易被质子化，并解释它们比简单胺碱性 增强的原因。