Electrophilic hou i loko o ke aloha kemika

No ka hou reactions wehewehe aku ma ke kahua o Nine Inch i huiʻia mai ka elua a oi mau puka lako. E noonoo i keʻano papa hana o electrophilic hou i ka pono mamuli o ka alkenes i - unsaturated acyclic hydrocarbons me kekahi mau mea paa. Ma waho aʻeo ia ia, i loko o ia mau loli 'lawe nā hydrocarbons ua mau mea paa, me cyclic.

Kahua o ka hoʻonaʻauao reacting ka hoʻomaka nā lātoma

Electrophilic hou i wahi i loko o kekahi mau kahua o ka hoʻonaʻauao. Electrophile me he maikaʻi ke kauoha a hana e like me ka huina'ine acceptor, a me ka papalua paa o ka alkene lātoma - like ka huina'ine mau pou. Nā huina lakou mau hana i ka mua pa-e yiaeaiiacaaeneiie eiiieaena. A laila, hoʻomaka i ka hou 'ana o π-eiiieaena ma ka ϭ-luna'. Carbocation ho okumu ma keia kahua a me kona kumupaʻa hooholo i ka uku o ka AaOIeIOUIeXAOAaIN i mau. Mahope carbocation reacts hoʻomaka koke i ka helehelena negatively hoopiiia nucleophile, a me ka hope huli ana huahana hana.

Kanawai o substituents ma ka naoh kōmi

Kauoha aku delocalization (ϭ +) ma ka carbocation mea hilinaʻi nui ma luna o ka loiloi mua hakakino 'ole. Noke inductive ia i hoike mai ai ia alakaila pae, hiki aku i ka emi i loko o kaʻoihana e pili kalapona'Ātoma. E like me ka hopena, i loko o ka lātoma me ka huina'ine donating substituent maoli ka hoahanau kumupaʻa o cation π-huina'ine nuʻa mea pono a me ka reactivity o ka lātoma like me ka a pau. Kanawai ma ka reactivity o ka huina'ine acceptors e e ku pono ana.

Keʻano papa hana o halogens e pili ana

E mākou nana i nui au mamuli o kaʻano papa hana o electrophilic hou o ka alkene i ka hana o ka AaOIeIOUIeXAOAaIN a me ka halogen.

1. Halogen lātoma hoʻokokoke mai nā waʻa paa ma waena o kalapona nā'ātoma a me polarized. Aie i ka hapa 'ia' maikaʻi malama ma kekahiʻaoʻao o ka lātoma halogen pulls na electrons π-hoopaa. No ka mea, aia no he ho okumu ana o ka lolelua ka π-eiiieaena.
2. I ka hiki mua electrophilic huna i pili i nā kalapona nā'ātoma, ho okumu i ke apo hookahi. Aia He He cyclic "onium" ion.
3. Ka i koe, papa mai huna halogen (olelo ikaika mai, papa mai nucleophile) ua reacted me onium ion, a pili ana ma kaʻaoʻao e ku pono ana, mai ka mua (particles) halogen. Ikeia hope huahana - māhū-1,2-digalogenalkan. Like me, IeIIeYOA ia lŘlŘ ma halogen cycloalkenyl.

Keʻano papa hana IeIIeYOA hydrohalic nāʻakika

Electrophilic hou o ka hydrogen halides a me sulfuricʻakika ana ole. Ma kaʻakika 'ia ua dissociated i loko o ka cation a me ka mea kemikala anion. Ikaika papa mai ion (electrophile) pepehi i ka π-hoopaa hui i kekahi o ka kalapona nā'ātoma. Carbocation ua hana, ai ka mea e pili kalapona'Ātoma ua ikaika ia. Next carbocation reacts me ka anion, e hana i ka huina hoonui hope o ka naoh.

Ke kuhikuhi ana o ka naoh ma waena o nā reagents a IeAUPIIe, IAa IO asymmetrical Markovnikov

Electrophilic hou ma waena o ka asymmetric nā lātoma mau ia lŘlŘ regioselectively. Kēia 'o ia hoʻi i ka mea e hiki isomers elua ua hana kaʻoi loa pono kekahi. Regioselectivity wehewehe Markovnikov ka rula, e like me a ka hydrogen ua pili i ka kalapona'Ātoma e pili ana me ka helu nui o nā hydrogen nā'ātoma (oi hydrogenated).

E maopopo keia rula, e mea pono e hoole i ka naoh i kela hilinaʻi nui ma luna o ke kumupaʻa o ka palapala carbocation. Kanawai o ka huina'ine kona mau pou, a acceptor substituents kau aʻela ma luna. Penei, electrophilic mawaho o hydrobromicʻakika e propene alakai i ke kahua o ka 2-bromopropane. Ka palapala cation me ka maikaʻi e mālama ai ma o ka kikowaena kalapona'Ātoma hou i ka pilina paʻa carbocation me ka maikaʻi 'āhewa' ana i loko o ka lōʻihi'Ātoma. E like me ka hopena, he bromine'Ātoma ua reacted me ka lua o ke kalapona'Ātoma.

Kanawai o ka huina'ine-withdrawing substituents ma luna o ka papa o ka AaOIeIOUIeXAOAaIN

Inā ka palapala lātoma he huina'ine withdrawing substituent i loaʻa i ka hopena maikaʻi inductive a / a mesomeric hookoia, electrophilic hou mea ku ei ka luna rula. 'O kekahi mau substituents: CF _3, COOH, CN. Ma keia hihia, i ka mea i oi aku ka mamao o ka maikaʻi malama o ka iniiaiie huina'ine withdrawing huiʻo ia i ka hou lio carbocation. E like me ka hopena, hydrogen pili i ka kalapona'Ātoma emi hydrogenated.

Universal mana o na rula, e nana me keia: ka AaOIeIOUIeXAOAaIN o ka asymmetric alkene a me ka asymmetric mea kemikala naoh i loaa mai ma ke ala o ka ho okumu ana o ka loa lio carbocation.