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烯烃为不饱和烃,其结构特征是分子中含有C=C双键,公式為CnH2n

目录

烯類命名编辑

E-Z 標示编辑

比較E-Z與cis-trans標示编辑

特性编辑

非鏡像異構(Diastereomerism)编辑

限制轉動编辑

相對穩定度编辑

反應编辑

製備编辑

製備烯烴有幾種不同方式。下面有的方式(像是威悌反應)我們這邊只簡短介紹,後面會更詳細的說明。

目前只需要知道這些是製備烯的方式就好。

鹵代烷(Haloalkanes)的脫鹵化氫(Dehydrohalogenation)编辑

 
用脫鹵化氫的方式合成烯烴

鄰二鹵化物(Vicinal Dihalides)的脫鹵(Dehalogenation)编辑

醇類脫水编辑

炔類還原编辑

威悌反應(Wittig Reaction)编辑

威悌反應類與三苯基磷鎓內鹽(威悌試劑)作用生成烯烴和三苯基氧膦的一類有機化學反應

 
透過威悌反應合成烯烴

馬爾科夫尼科夫規則(Markovnikov's Rule)编辑

Before we continue discussing reactions, we need to take a detour and discuss a subject that's very important in Alkene reactions, "Markovnikov's Rule." This is a simple rule stated by the Russian Vladmir Markovnikov in 1869, as he was showing the orientation of addition of HBr to alkenes.

His rule states:"When an unsymmetrical alkene reacts with a hydrogen halide to give an alkyl halide, the hydrogen adds to the carbon of the alkene that has the greater number of hydrogen substituents, and the halogen to the carbon of the alkene with the fewer number of hydrogen substituents" (This rule is often compared to the phrase: "The rich get richer and the poor get poorer." Aka, the Carbon with the most Hydrogens gets another Hydrogen and the one with the least Hydrogens gets the halogen)

This means that the nucleophile of the electophile-nucleophile pair is bonded to the position most stable for a carbocation, or partial positive charge in the case of a transition state.

例子编辑

馬氏規則產物编辑

馬氏規則加成编辑

反馬氏規則加成编辑

為什麼馬氏規則可行?编辑

規則例外编辑

加成反應编辑

硼氫化(Hydroboration)编辑

硼氫化/氧化编辑

立體化學和定向编辑

汞氧化/去汞(Oxymercuration/Reduction)编辑

狄耳士–阿德爾反應(Diels-Alder Reaction)编辑

催化加氫(Catalytic addition of hydrogen)编辑

親電加成(Electrophilic addition)编辑

鹵化(Halogenation)编辑
氫鹵化(Hydrohalogenation)编辑

氧化编辑

聚合编辑

取代和消除反應機制编辑

親核取代反應编辑

備註编辑

SN1 vs SN2编辑

SN2 反應编辑

Reactivity Due to Structure of SN2编辑

親核性(Nucleophilicity)编辑

List of descending nucleophilicities编辑

離去基编辑

離去基的相對反應性编辑

溶劑编辑

Relative Reactivity of Solvents编辑

SN1 反應编辑

Reactivity Due to Structure of SN1编辑

溶劑编辑

摘要编辑

消除反應(Elimination Reactions)编辑

Note编辑

E1 vs E2编辑

反應速率编辑
查依采夫規則(Zaitsev's Rule)编辑

查依采夫规则,也稱作扎伊采夫规则扎伊切夫规则,是指卤代烃在进行消除反应时,主要生成物會是碳碳双键上取代基較多的烯烃(最穩定的烯烃)。

例如,2-丁醇进行消除反应时,主要生成物是2-丁烯1-丁烯只是次要生成物。

 

E2编辑

Reactivity Due to Structure of E2编辑

E1编辑

References编辑