Electrophilic mgbakwunye na Organic Chemistry

N'ihi na mgbakwunye Jeremaya ji guzobe chemical ogige abụọ ma ọ bụ karịa na-amalite ihe. Tụlee usoro nke electrophilic mgbakwunye na-adaba adaba atụ nke alkenes - unsaturated acyclic hydrocarbons na otu abụọ nkekọ. Ke adianade ha, dị otú mgbanwe buru ọzọ hydrocarbons enwe multiple agbụ, tinyere cyclic.

Nkebi imeghachi omume na-amalite na ụmụ irighiri ihe

Electrophilic mgbakwunye na-ewe ebe ọtụtụ nkebi. Electrophile na-enwe ụgwọ ọrụ dị ka ihe elektrọn acceptor, na abụọ nkekọ nke ihe alkene molekul - dị ka ihe elektrọn-enye onyinye. The abụọ ogige etolite a mbụ p-obodo mgbagwoju. Mgbe ahụ malitere mgbanwe nke π-mgbagwoju ke ϭ-mgbagwoju. Carbocation n'usoro na a na ogbo na ya kwụsie ike ikpebi na ọnụego nke mmekọrịta n'ozuzu. Mgbe nke ahụ gasịrị carbocation mkpatụ ngwa ngwa na ele mmadụ anya n'ihu adịghị mma ebubo nucleophile na ikpeazụ akakabarede ngwaahịa kpụrụ.

Mmetụta nke substituents na mmeghachi omume ọnụego

Ana delocalization (ϭ +) na carbocation ọ na-adabere na mbụ molekụla Ọdịdị. Positive inductive mmetụta nke na-egosipụta alkyl otu, na-eduga ná a ọnụ ke ndebe n'akụkụ carbon atọm. N'ihi ya, na molekul na elektrọn inye onyinye substituent enwekwu ikwu nkwụsi ike nke cation π-elektrọn njupụta bụ n'ihi na reactivity nke molekul dị ka a dum. Mmetụta na reactivity nke elektrọn acceptors ga-abụghị.

The usoro nke halogens njikọ

Ka anyị tụlee ihe nkowa nke usoro nke electrophilic mgbakwunye na nke alkene ka ihe atụ nke na mmekọrịta na halogen.

1. Halogen molekul na-eru nso na abụọ nkekọ dị n'etiti carbon atọm na-ekewasị. N'ihi na ikpe ziri ụgwọ na otu njedebe nke molekul halogen akwusila na electrons π-nkekọ. Ebe ọ bụ na a kpụọ ihe ejighị n'aka π-mgbagwoju.
2. Na nzọụkwụ ọzọ electrophilic urughuru jikọọ abụọ carbon atọm, akpụ a mgbanaka. E nwere a cyclic "onium" ion.
3. Ndị fọdụrụ ebubo urughuru halogen (ghaghị ebubo nucleophile) na-meghachi omume na onium ion na enyekwara n'akụkụ nke ọzọ gafere si aga ahụ halogen. Na-egosi ikpeazụ ngwaahịa - trans-1,2-digalogenalkan. N'otu aka ahụ, na-ekekọta emee site halogen cycloalkenyl.

The usoro na-ekekọta hydrohalic asịd

Electrophilic mgbakwunye na nke hydrogen halides na igirigi ibu sulphuric acid ime ma ọ bụghị. Ke acidic gburugburu ebe obibi na-dissociated n'ime a cation na reagent anion. Ghaghị ebubo ion (electrophile) awakpo π-nkekọ tinyere otu nke carbon atọm. Carbocation a kpụrụ, nke bụ n'akụkụ carbon atọm na-ghaghị ebubo. Next carbocation mkpatụ na anion etolite ikpeazụ ngwaahịa nke mmeghachi omume.

Ntụziaka nke mmeghachi omume n'etiti reagents na-emekarị asymmetrical Markovnikov

Electrophilic adianade n'etiti abụọ akpàràkpà ụmụ irighiri emee regioselectively. Nke a pụtara na abụọ e nwere ike isomers a kpụrụ ọkacha mma nanị otu. Regioselectivity akọwa Markovnikov isi, dị ka nke hydrogen bụ mmasị na a carbon atọm ejikọrọ na a ukwuu nke ndị ọzọ hydrogen atọm (ọzọ hydrogenated).

Iji ghọta nke a na-achị, ọ dị mkpa iji na-echeta na mmeghachi omume ọnụego na-adabere na nkwụsi ike nke etiti carbocation. Mmetụta nke elektrọn na-enye onyinye na acceptor substituents kwuru n'elu. N'ihi ya, electrophilic mgbakwunye na nke hydrobromic acid ka propene-edu ndú ka e guzobere 2-bromopropane. The etiti cation na a mma ụgwọ on Central carbon atọm ọzọ mụ carbocation na a mma ụgwọ nke ukwuu atọm. N'ihi ya, a bromine atọm na-meghachi omume na a abụọ carbon atọm.

Mmetụta nke elektrọn-wezụgara substituents na N'ezie nke na mmekọrịta

Ọ bụrụ na ndị mbụ molekul nwere elektrọn wezụgara substituent nke nwere a na-adịghị mma inductive na / ma ọ bụ mesomeric mmetụta, electrophilic mgbakwunye bụ megide n'elu iwu. Ihe Nlereanya nke ndị dị otú ahụ substituents: CF _3, COOH, CN. Na nke a, ihe ka ukwuu n'ebe dị anya nke oma ndebe nke bụ isi elektrọn wezụgara otu anam a ọzọ mụ carbocation. N'ihi ya, hydrogen jikọọ carbon atọm obere hydrogenated.

Universal version nke iwu ga-ele anya dị ka nke a: na na mmekọrịta nke ihe akpàràkpà alkene na ihe akpàràkpà reagent mmeghachi omume ha retara site n'ụzọ nke guzobere kasị mụ carbocation.