Qhov Tseem Ceeb Qhov txawv - Alkylation vs Acylation
Alkylation thiab acylation yog ob qhov kev hloov pauv ntawm electrophilic hauv Organic chemistry. Qhov sib txawv tseem ceeb ntawm alkylation thiab acylation yog pab pawg koom nrog hauv kev hloov pauv. Ib pawg alkyl raug hloov hauv cov txheej txheem ntawm alkylation thaum ib pawg acyl hloov mus rau lwm qhov sib xyaw hauv acylation. Thaum qhov kev hloov pauv no tshwm sim hauv lub nplhaib benzene nyob rau hauv cov xwm txheej catalytic, nws hu ua "Friedel- crafts acylation/alkylation."
Alkylation yog dab tsi?
Kev hloov ntawm ib pawg alkyl los ntawm ib lub molecule mus rau lwm lub molecule yog hu ua 'alkylation.' Cov pab pawg alkyl pauv tuaj yeem yog alkyl carbocation, dawb radical, carbanion, lossis carbine. Alkyl pawg yog ib feem ntawm cov molecule uas muaj cov qauv dav dav ntawm C nH2 n + 1 (n - yog tus lej, nws sib npaug rau tus naj npawb ntawm Carbon hauv pawg alkyl).
Acylation yog dab tsi?
Cov txheej txheem ntawm kev ntxiv ib pawg acyl rau cov tshuaj lom neeg hu ua acylation. Acylating tus neeg sawv cev yog cov tshuaj sib xyaw uas muab cov acyl pawg hauv cov txheej txheem no. Cov piv txwv ntawm acylating agents yog; Acyl halides, acetyl chlorides.
Qhov txawv ntawm Alkylation thiab Acylation yog dab tsi?
Definition of Alkylation thiab Acylation:
Alkylation: Alkylation yog kev hloov ntawm ib pawg alkyl los ntawm ib lub molecule mus rau lwm lub molecule.
Acylation: Acylation yog txheej txheem ntawm kev ntxiv ib pawg acyl rau cov tshuaj lom neeg.
Agents:
Alkylation:
Cov piv txwv ntawm cov tshuaj alkylating yog;
- Alkyl carbocations
- dawb radical
- Carbanions
- Carbines
Acylation:
Acyl halides feem ntau yog siv los ua acylating agents; lawv muaj zog heev electrophiles thaum kho nrog qee cov hlau catalysts.
Acyl halides:
Ethanoil chloride CH3-CO-Cl
Acyl anhydrides ntawm Carboxylic acids
Alkylation thiab Acylation Mechanism:
Alkylation:
Alkylation ntawm benzene: Hauv qhov tshuaj tiv thaiv no, hydrogen atom hauv lub nplhaib benzene hloov los ntawm pawg methyl.
Acylation:
Acylation ntawm Benzene: Hauv qhov tshuaj tiv thaiv no, Hydrogen atom hauv lub nplhaib benzene hloov los ntawm CH3CO- pawg.
Daim ntawv thov ntawm Alkylation thiab Acylation:
Alkylation:
Hauv cov txheej txheem roj refining: Lub alkylation ntawm isobutene nrog olefins yog siv los txhim kho roj av. Nws tsim cov alkylates hluavtaws uas muaj C7-C8 chains. Cov no yog siv los ua cov khoom lag luam zoo rau cov roj av.
Hauv tshuaj: Ib chav tshuaj hu ua "alkylating antineoplastic agents" yog siv rau hauv cov txheej txheem alkylation hauv kev siv tshuaj khomob. Qhov no yog ua los ntawm alkylation ntawm DNA nrog cov tshuaj kom puas DNA ntawm cov qog nqaij hlav cancer.
Acylation:
In Biology:
Protein acylation: Tom qab kev hloov pauv ntawm cov proteins yog ua los ntawm kev txuas cov pab pawg ua haujlwm los ntawm acyl linkages.
Fatty acylation: Nws yog cov txheej txheem ntawm kev ntxiv fatty acids rau cov amino acids tshwj xeeb (myristoylation lossis palmitoylation).
txwv ntawm Alkylation thiab Acylation:
Alkylation:
- YThaum halides siv hauv alkylation, nws yuav tsum yog alkyl halide. Vinyl lossis aryl halides tsis tuaj yeem siv vim lawv qhov nruab nrab carbocations tsis ruaj khov.
- Cov tshuaj tiv thaiv no suav nrog cov txheej txheem carbocation rearrangement, thiab cov khoom sib txawv yuav tsim.
- Poly-alkylation: Txuas ntau dua ib pawg alkyl rau lub nplhaib. Qhov no tuaj yeem tswj tau los ntawm kev ntxiv cov benzene ntau dhau.
Acylation:
- Qhov acylation tsuas yog tsim cov ketones. Nws yog vim qhov decomposition ntawm HOCl rau CO thiab HCl raws li cov kev mob tshwm sim.
- Tsuas yog cov activated benzenes reactive hauv acylation. Nyob rau hauv cov ntaub ntawv no, benzenes yuav tsum reactive dua ib tug mono-halobenzene.
- Thaum cov pab pawg aryl amine muaj nyob, Lewis acid catalyst (AlCl3) tuaj yeem tsim qhov nyuaj ua rau lawv tsis muaj zog.
- Thaum muaj pab pawg amine thiab cawv, lawv tuaj yeem muab N lossis O acylations es tsis txhob siv lub nplhaib acylation.
Definition of Acyl Group:
Ib pawg ua haujlwm uas muaj ob chav sib koom ua ke oxygen atom thiab ib pawg alkyl rau carbon atom (R-C=O). Hauv cov organic chemistry, pawg acid feem ntau yog muab los ntawm carboxylic acids. Aldehydes, ketones thiab esters kuj muaj acyl pawg.
