Qhov sib txawv tseem ceeb ntawm regioselectivity thiab stereoselectivity yog tias regioselectivity yog hais txog kev tsim ntawm ib qho chaw isomer tshaj lwm tus. Meanwhile, stereoselectivity yog hais txog kev tsim ntawm ib qho stereoisomer tshaj lwm tus.
Cov ntsiab lus regioselectivity thiab stereoselectivity yog qhov tseem ceeb heev hauv cov organic synthesis. Cov ntsiab lus no piav qhia txog cov qauv ntawm cov khoom kawg ntawm cov tshuaj tiv thaiv. Cov ceg ntawm chemistry uas kawm regioselectivity yog hu ua regiochemistry thaum lub ceg ntawm chemistry uas kawm stereoselectivity hu ua stereochemistry.
Regioselectivity yog dab tsi?
Regioselectivity yog hais txog kev tsim lossis rhuav tshem cov tshuaj lom neeg hauv ib qho kev coj mus rau tag nrho lwm cov lus qhia uas ua tau. Lub tswv yim no tuaj yeem siv rau kev txiav txim siab txoj haujlwm ntawm cov tshuaj sib xyaw uas cov tshuaj reagent tuaj yeem cuam tshuam, piv txwv li protons cuam tshuam los ntawm lub hauv paus muaj zog.
Daim duab 01: Halohydrin Formation Reaction Qhia Regoselectivity
Lub sij hawm regioselectivity tshwm sim los ntawm kev sib xyaw ntawm ob lub tswv yim tshuaj uas tshwm sim hauv tib cov tshuaj tiv thaiv; "regio + xaiv" txhais tau hais tias tsim ntawm qhov chaw isomer (los yog kev cai lij choj isomer) yog nyiam (los yog xaiv). Txhua qhov kev cuam tshuam nrog kev xaiv tsa rov ua dua muab cov kev sib xyaw ntawm kev cai lij choj isomers nrog cov khoom tseem ceeb thiab cov khoom me me. Txawm li cas los xij, qee zaum cov khoom me tsis tuaj yeem ntes tau vim tias nws tau tsim los ntawm qhov tsawg heev.
Stereoselectivity yog dab tsi?
Stereoselectivity yog hais txog kev tsim ntawm qhov sib npaug ntawm cov stereoisomers thaum muaj tshuaj tiv thaiv. Nws tsuas yog txhais tau hais tias cov tshuaj tiv thaiv muab ib qho stereoisomer tshaj lwm tus raws li cov khoom kawg ntawm cov tshuaj tiv thaiv. Tsis tas li ntawd, hom kev tshwm sim no tshwm sim rau ob lub sijhawm sib txawv. Ib qho yog thaum lub sij hawm tsis yog-stereospecific creation ntawm ib tug tshiab stereocenter, thiab lwm yam yog thaum lub sij hawm tsis-stereospecific transformation ntawm ib tug stereocenter uas twb muaj lawm. Qhov kev xaiv no tshwm sim vim muaj kev cuam tshuam tsis zoo thiab cov teebmeem hluav taws xob.
Stereoselectivity yuav txawv ntawm qhov sib txawv tab sis tsis muaj qhov tshwm sim ua ib qho tag nrho stereoisomer; tag nrho cov tshuaj tiv thaiv no muab kev sib xyaw ntawm stereoisomers nrog ib qho tseem ceeb thiab cov khoom me me. Txawm li cas los xij, qee zaum cov khoom me tsis tuaj yeem ntes tau vim tias nws tau tsim los ntawm tus nqi tsawg heev.
Muaj ntau hom stereoselectivity.
Enantioselective - ib daim ntawv enantiomer tshaj lwm cov isomers; chiral molecule tsim los ntawm achiral molecule, qib ntawm kev xaiv yog ntsuas los ntawm enantiomeric tshaj
Diasereoselective - ib qho diastereomer daim ntawv hla lwm isomer; ib lossis ntau qhov chaw chiral cov ntaub ntawv los ntawm ib qho chaw achiral lossis ib lub chaw chiral preexisting, qhov degree ntawm kev xaiv tuaj yeem ntsuas los ntawm diastereomeric ntau dhau
Stereoconvergence - rov qab ntawm stereoselectivity nyob rau hauv uas ob qhov sib txawv stereoisomers tsim ib qho stereoisomer
Qhov txawv ntawm Regioselectivity thiab Stereoselectivity yog dab tsi?
Cov ntsiab lus regioselectivity thiab stereoselectivity yog qhov tseem ceeb heev hauv cov organic synthesis. Qhov sib txawv tseem ceeb ntawm regioselectivity thiab stereoselectivity yog tias regioselectivity yog hais txog kev tsim ntawm ib qho chaw isomer tshaj lwm tus, whereas stereoselectivity yog hais txog kev tsim ntawm ib qho stereoisomer tshaj lwm tus. Yog li ntawd, regioselectivity tsim ib txoj hauj lwm los yog kev cai lij choj isomer thaum stereoselectivity tsim stereoisomer. Txawm li cas los xij, ob txoj hauv kev ua rau lwm tus isomer ua cov khoom me nrog rau cov isomer nyiam, uas yog cov khoom loj. Tsis tas li ntawd, txoj kev kawm ntawm regioselectivity los nyob rau hauv regiochemistry, whereas txoj kev kawm ntawm stereoselectivity los nyob rau hauv stereochemistry.
Hauv qab infographic qhia txog qhov sib txawv ntawm regioselectivity thiab stereoselectivity.
Summary – Regioselectivity vs Stereoselectivity
Cov ntsiab lus regioselectivity thiab stereoselectivity yog qhov tseem ceeb heev hauv cov organic synthesis. Qhov sib txawv tseem ceeb ntawm Regioselectivity thiab Stereoselectivity yog tias regioselectivity yog hais txog kev tsim ntawm ib qho chaw isomer tshaj lwm tus, whereas stereoselectivity yog hais txog kev tsim ntawm ib qho stereoisomer tshaj lwm tus. Txoj kev kawm ntawm regioselectivity los nyob rau hauv regiochemistry, whereas txoj kev kawm ntawm stereoselectivity los nyob rau hauv stereochemistry.
