Ukongeza Electrophilic Chemistry Organic

Ukuze zizongeze reactions luphawulwa ukuyilwa anemichiza ngezinto ezimbini okanye ngaphezulu lokuqalisa. Cinga indlela yokudibanisa electrophilic kumzekelo elula alkenes - hydrocarbon ezihluthiyo acyclic omnye bond kabini. Ngaphandle kwabo, utshintshwano enjalo ezinye hydrocarbon ukuba ngeentambo ezininzi, kuquka elibujikele.

Amanqanaba ngokuhlanganisa molekyuli ukuqala

Ukongeza Electrophilic kwenzeka ngokwamanqanaba eziliqela. Electrophile ukuba izenzo entle umthetho njengento acceptor electron, kwaye iqhina kabini i molecule alkene - njengoko ukunikela electron. Ezi zinto zimbini zenza i p-ekucaphukisayo complex yokuqala. Ke iqala inguqu π-ezintsokothileyo ϭ-complex. Carbocation uluhlu kweli nqanaba kunye nozinzo yayo ukujonga izinga yentsebenziswano ngokubanzi. Emva koko carbocation ihlangana ngokukhawuleza kunye nucleophile engaphelelanga kakubi amacala, imveliso ukuguqulwa yokugqibela kwakhiwa.

Isiphumo substituents kwi izinga basabela

Uyala delocalization (ϭ +) e carbocation kuxhomekeka kubume sokuqala molecule. ukusebenza ezenza Positive esizibonakalisa iqela alkyl, kukhokelela ekuncipheni intlawulo ezikufutshane carbon atom. Ngenxa yoko, kweli molecule kunye electron nokunikela substituent kwandisa uzinzo usisizalwane imbo π-electron konga ngenxa kunye reactivity kwemolekyuli xa iyonke. Ukusebenza reactivity of acceptors electron iya kuba esahlukileyo.

Indlela kokudityaniswa halogens

Makhe sihlolisise ngokweenkcukacha indlela yokudibanisa electrophilic le alkene ukuba umzekelo yentsebenziswano kunye halogen.

1. Halogen molecule siwungena iqhina kabini phakathi athom carbon kanye namaza. Ngenxa intlawulo ngokungaphelelanga omhle kwelinye ekupheleni halogen molecule olawula electron π-bond. Ekubeni kukho ekumiseni iyahlozinga π-complex.
2. Xa inyathelo elilandelayo isuntswana electrophilic uqhagamshele athom ezimbini carbon, bakha ngomsesane. Kukho elibujikele "onium" ion.
3. Esiseleyo icala yamasuntswana halogen (nucleophile kakuhle ebizwayo) liyahlonyelwa wasabela ngokuba kwaku- onium kwaye uzibandakanya kwelinye icala ukusuka amasuntswana halogen yangaphambili. Ivela imveliso yokugqibela - yothutho-1,2-digalogenalkan. Ngokufanayo, ukunamathela kwenzeka halogen cycloalkenyl.

Isixhobo attachment asidi hydrohalic

Ukongeza Electrophilic of halides hydrogen sulphuric acid kwenzeka ngenye indlela. Kwimeko-bume asidi into inqanyulwe ube zesiqinisekiso kunye reagent anion. ion kakuhle icala (electrophile) sihlasela π-bond kukhatshwa ukuya kwenye atom carbon. Carbocation ibunjiwe, apho carbon atom esecaleni kakuhle ityala. carbocation Okulandelayo ihlangana kunye anion ukwenza imveliso yokugqibela basabela njani.

Indlela abasabela phakathi wezenzi kwaye zikholisa azilingani Markovnikov

Ukongeza Electrophilic phakathi molekyuli ezimbini yezi kwenzeka regioselectively. Oku kuthetha ukuba isomers ezimbini kusenzeka abunjwe kukhethwa nje omnye. Regioselectivity ichaza ulawulo Markovnikov kaThixo, njengoko apho hydrogen iqhotyoshelwe apha kwi-atom carbon enxulumene kunye nenani elikhulu kwezinye athom hydrogen (ngakumbi hydrogenated).

Ukuze uqonde lo mthetho, kubalulekile ukukhumbula ukuba izinga indlela ixhomekeke kuzinzo carbocation eliphakathi. Isiphumo electron abanikelayo kunye acceptor substituents zikhankanywe apha ngasentla. Ngenxa yoko, Ngaphezu electrophilic of hydrobromic acid ukuba propene ukuba ukhokelele ekubeni kusekwe ka-bromopropane 2. Kwasetyenzi- eliphakathi nentlawulo entle central carbon atom ngakumbi carbocation esitalini nentlawulo eyakhayo atom kakhulu. Ngenxa yoko, i-atom bromine into awasabela ngayo kunye a atom carbon yesibini.

Isiphumo substituents electron-ukurhoxisa kwikhosi intsebenziswano

Ukuba molecule yokuqala iqulethe electron ukurhoxisa substituent ene-ezenza kakubi kunye / okanye ukusebenza mesomeric, Ngaphezu electrophilic uchasene nemigaqo ngasentla. Imizekelo substituents ezinjalo: CF _3, COOH, CN. Kulo mzekelo, kokukhona umgama isigxina ezintle zeqela ukurhoxisa electron lokuqala lenza carbocation womelele ngakumbi. Ngenxa yoko, hydrogen odityaniswe carbon atom hydrogenated ngaphantsi.

version Universal imithetho iza kukhangeleka ngolu hlobo: impefumlelwano i alkene yezi kwaye i inzuzo reagent reaction yezi ngendlela lokusekwa carbocation kakhulu izinzile.