第十一章 氧化一还原反应 Oxidation- Reduction Reaction
第十一章 氧化 — 还原反应 Oxidation – Reduction Reaction
本章主要内容 一、氧化还原反应基本概念 二、还原 一催化氢化 一电子-质子还原(液氨/金属) 一负氢还原(金属氢化物) 三、氧化 一醇 一不饱和烃 醛酮 四、酚醌氧化还原与生命体电子传递
本章主要内容 一、氧化 -还原反应基本概念 还原反应基本概念 二、还原 — 催化氢化 — 电子 -质子还原(液氨 质子还原(液氨 /金属) — 负氢还原(金属氢化物) 负氢还原(金属氢化物) 三、氧化 — 醇 — 不饱和烃 — 醛酮 四、酚醌氧化还原与生命体电子传递 四、酚醌氧化还原与生命体电子传递
氧化-还原反应基本概念 Oxidation-reduction reactions or redox reactions(氧化还原反应)are an important group of organic reactions those involve the tranfer of electrons from one molecular to another ■ Loss of electrons is oxidation失电子 氧化 Gain of electrons is Reduction得电子 还原
一、氧化-还原反应基本概念 Oxidation Oxidation -reduction reactions or reduction reactions or redox reactions reactions (氧化还原反应) 氧化还原反应) are an important group of organic an important group of organic reactions those reactions those involve the involve the tranfer tranfer of electrons electrons from one molecular to from one molecular to another another Loss of Electrons is Loss of Electrons is Oxidation Oxidation 失电子 氧化 Gain of Electrons is of Electrons is Reduction Reduction 得电子 还原 R d i t ( 还原剂) d
无机化学中的氧化还原表现为元素的原子价 态的变化 ■在有机化学中,碳始终是四价,其氧化还原 的特点是部分的电子得失 ■因此广义的说多数有机反应都是氧化还原反 应,不过习惯上将加氧或脱氢的反应称为氧 化,脱氧或加氢的反应称为还原 C:H C-cl 十
无机化学中的氧化还原表现为元素的原子价 无机化学中的氧化还原表现为元素的原子价 态的变化 在有机化学中,碳始终是四价,其氧化还原 在有机化学中,碳始终是四价,其氧化还原 的特点是部分的电子得失 的特点是部分的电子得失 因此广义的说多数有机反应都是氧化还原反 因此广义的说多数有机反应都是氧化还原反 应,不过习惯上将加氧或脱氢的反应称为氧 习惯上将加氧或脱氢的反应称为氧 化,脱氧或加氢的反应称为还原 化,脱氧或加氢的反应称为还原 C : H C : Cl
RCH-CHR Pt RCh CHoR an alkene This is a reduction reaction and it also can be called as an addition reaction Br br Br2 RCHECHR RCHCHR an alkene This is an addition reaction but in fact. it can be considered as an oxidation reaction
This is a reduction reaction, and it also can be called as an addition reaction. This is an addition reaction, but in fact, it can be considered as an oxidation reaction
1. NaBH RCH 4 2H+Ho≥RCH2OH 脱氧或加氢 an aldehyde 的反应 O 称为还原 H2NNH2 RCR HOA> RCHR a ketone O H2 crO4 RCH RCOH 加氧或脱氢 an aldenyde 的反应 称为氧化 OH O H2crO4 RCHR RCR an alcohol
脱氧或加氢 的反应 称为还原 加氧或脱氢 的反应 称为氧化
氧化-还原反应基本概念 if the number of c-h bonds has increased or the number of c-o c-n or c-x bonds has decreased the compound has been reduced. In other way round, the compound has been oxdized The oxidation state of a carbon atom equals the number of its C-o, C-N, or C-X bonds
一、氧化-还原反应基本概念 If the number of C If the number of C -H bonds H bonds has increased or the number increased or the number of C -O, C -N, or C -X bonds has decreased, the X bonds has decreased, the compound has been compound has been reduced reduced. In other way round, the compound has other way round, the compound has been oxdized oxdized. The oxidation state oxidation state of a carbon atom of a carbon atom equals the number of its C equals the number of its C -O, C -N, or C -X bonds. X bonds
Oxidation state(氧化态) oxidation reactions OXIDATION STATE 0 2 number of c-z bonds Z=O.N or halogen CH CH3OH HCH HCOH 0=C=0 CH3OCH3 CH3 CCH3 CH3COCH3 CH3OCOCH3 NCH3 O CH3CCH3 CH3 CNH2 CH3 OCNHCH3 OCH O CH3 CCH3(H) CH3 CCI CICCI OCH3 reduction reactions
Oxidation State(氧化态 )
二、还原反应一催化氢化 the reduction by addition of two hydrogen Atoms(通过加氢的还原) can be carried out in the presence of a metal catalyst, so it is called Catalytic Hydrogenation(催化氢化) alkenes(C=C), alkynes(C=C) imines (C=N ),nitriles(C=N)Yes aldehydes or ketones(C=o) .But, RCOOH, RCOOR', and RCONHR'+No
二、还原反应 — 催化氢化 The reduction by addition of two hydrogen Atoms (通过加氢的还原)can be carried out in the presence of a metal catalyst, so it is called Catalytic Hydrogenation (催化氢化). alkenes ( C=C ), alkynes ( C ≡C ) imines ( C=N ), nitriles ( C ≡N ) aldehydes or ketones ( C=O ) Yes But, RCOOH, RCOOR’, and RCONHR’ No
二、还原反应一催化氢化 1机理 催化氢化的机理还没有完全研究清楚,通 常认为氢吸附在金属的表面,烯烃也通过 p-轨道与金属络合,然后烯烃与氢加成。 n其立体化学特征是—syn- addition H H H H H--C-C--H H H 题-8一题
二、还原反应 — 催化氢化 1. 机理 催化氢化的机理还没有完全研究清楚,通 催化氢化的机理还没有完全研究清楚,通 常认为氢吸附在金属的表面,烯烃也通过 常认为氢吸附在金属的表面,烯烃也通过 p -轨道与金属络合,然后烯烃与氢加成。 轨道与金属络合,然后烯烃与氢加成。 其立体化学特征是 其立体化学特征是 —— Syn -addition addition