Txoj hauv kev kom tau txais cov tshuaj txo qis yog dab tsi? Ntawm no yog ntau txoj hauv kev los ua amines uas tsis ua rau ntau dhau alkylation. Txoj kev no yog qhov yooj yim heev thiab pob tshab txawm rau cov pib hauv chemistry. Tsuas yog ob peb yam yooj yim. Txawm li cas los xij, koj yuav xav tau ntau cov tshuaj reagents uas nyuaj nrhiav kev lag luam. Cov qauv no, piv txwv li, tuaj yeem siv los ua kom txo qis ntawm cov amino acids.
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Pib nrog aldehyde lossis ketone, tsim ib qho imine (analogous rau nitrogen aldehyde lossis ketone). Txo cov imine nrog cov tshuaj txo qis xws li sodium cyanoborohydride (NaBH3CN), sodium borohydride (NaBH4) lossis sodium acetoxyborohydride (NaBH(Oac)3). Nws hloov tawm amine tshiab. Tsis tas yuav cais cov imine nruab nrab (uas tuaj yeem ua rau qee qhov tsis ruaj khov). Kev txo qis tuaj yeem ua tiav hauv qhov chaw (piv txwv li hauv tib lub hwj tshuaj tiv thaiv kab mob),ces muab lub sij hawm txaus rau daim ntawv.
txheej txheem no hu ua reductive amination. Lub npe "reductive amination" kuj tau ntsib. Nov yog ib qho piv txwv tshwj xeeb: hydro-methylbenzylamine.
Cia peb hais tias koj muaj thawj amine zoo li benzylamine thiab koj xav ua hydro-methylbenzylamine. Koj yuav ua li cas? Kev kho ncaj qha ntawm benzylamine nrog tus neeg sawv cev alkene (piv txwv li, methyl iodide) yuav ua rau muaj kev tsim loj ntawm cov tsis xav tau tertiary amine (piv txwv li, dealkylation).
Yog, koj tuaj yeem sim cais cov amine theem nrab uas yog tsim los ntawm tertiary amine, tab sis peb yuav tsis mus daws qhov 10-30% concentration uas txoj kev no muab. Kev sib cais sib xyaw yog qhov zoo ntawm daim ntawv, tab sis nws tuaj yeem ua rau mob tiag tiag hauv kev xyaum. Puas muaj lwm txoj hauv kev los ua qhov no? Sim txo qis amination. Qhov no yog txoj kev tswj hwm ntau dua ntawm kev tsim cov nitrogen-carbon bonds.
Tom qab lub mine raug tsim, nws yuav tsum raug txo kom cov amine. Cov neeg paub txog kev txo qis sodium borohydride (NaBH4) tuaj yeem siv rau txoj haujlwm no. Tej zaum nws yuav nco qab tias NaBH4 yog siv los txo aldehydes thiab ketones. Muaj ob qho lwm yam uas siv cov tshuaj txo qis qis: sodium cyanoborohydride (NaBH3CN) thiab sodium acetoxyborohydride (NaBH (Oac) 3). Rau peb lub hom phiaj, lawv tuaj yeem suav tias yog tib yam. Hauv kev xyaum, NaBH3CN me ntsis zoo dua NaBH4.
Daim ntawv thov
Kev txo qis amination yog heevntau yam thiab tuaj yeem siv los tsim kom muaj ntau yam sib txawv ntawm pawg alkyl ntawm amines. Qhov zoo tshaj yog cov bands ib zaug xwb.
Ketones kuj ua haujlwm
YYuav ua li cas txog ketones? Lawv ua hauj lwm ib yam nkaus! Siv ib qho ketone, uas yuav coj peb mus rau cov ceg alkyl hloov pauv ntawm cov amine. Piv txwv li, siv acetone hauv kev txo qis tom ntej no muab ib pawg isopropyl. Ntxiv mus, txhua yam yog yooj yim.
Sequential amination yog lwm qhov tseem ceeb ntawm cov tshuaj tiv thaiv kev txo qis. Qhov tshwj xeeb yog tias ob (lossis peb, yog tias ib qho pib nrog ammonia) cov txheej txheem tuaj yeem siv ua ntu zus. Piv txwv li, saib cov synthesis ntawm tertiary amine. Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias qhov sib lawv liag ntawm cov tshuaj tiv thaiv tsis yog qhov tseem ceeb ntawm no. Peb tuaj yeem ua thawj qhov kev txo qis nrog benzaldehyde thawj zaug thiab acetone thib ob thiab tseem tau txais cov khoom qub.
Intramolecular reductive amination
Thaum kawg, muaj cov ntaub ntawv intramolecular uas ib txwm ua rau cov tub ntxhais kawm mob taub hau. Yog tias cov molecule muaj ob pawg amine thiab carbonyl, nws tuaj yeem muab cov amine cyclic. Thaum rub tawm cov khoom ringing, nws raug nquahu kom suav thiab suav koj cov ces kaum. Ntau tus tub ntxhais kawm ua yuam kev thaum rov kos dua, uas tsim nyog siv sijhawm.
Ua haujlwm rov qab: npaj rau kev txo qis qis
Qhov no yuav siv sij hawm me ntsis, tab sis txo qis amination yog ib txoj hauv kev muaj zog heev los ua amines. Nws muaj txiaj ntsig zoo kom muaj peev xwm xav rov qab los ntawm cov khoom amine mus rau cov khoom siv raw zoo li cas.
Feem ntau, kev txo qis amination yog qhov muaj zog thiab muaj txiaj ntsig zoo rau kev tsim cov amines. Txhua tus menyuam kawm ntawv tuaj yeem nkag siab. Yog tias koj xav rov ua cov tshuaj tiv thaiv no hauv tsev, txoj hauv kev yooj yim tshaj rau tus pib yog ua kom txo qis ntawm glutamic acid.
