Vim tias cov carbocation xav tias lub hom phiaj, kev tawm tsam los ntawm nucleophile tuaj yeem tshwm sim los ntawm ob sab ntawm lub dav hlau. Qhov no ua rau kev tsim ntawm sib tov ntawm enantiomers, hu ua kev sib xyaw ntawm haiv neeg. Qhov no yog qhov sib piv rau SN2 uas tsuas yog tsim cov stereoisomer inverted ntawm cov reactant.
Puas racemization tshwm sim hauv SN2?
Yog tias ob qho txheej txheem tshwm sim rau tib qib hauv cov tshuaj tiv thaiv nrog lub chaw tshuaj tiv thaiv asymmetric, tus neeg sib tw tau txais. … Yog hais tias tuav thiab inversion tshwm sim rau tib theem, cov tshuaj tiv thaiv yields ib racemate (racemization).
Qhov twg muab kev sib tw sib tw SN1 lossis SN2?
Cov carbocation thiab nws cov hloov pauv yog tag nrho nyob rau hauv tib lub dav hlau (Daim duab 1), txhais tau hais tias cov nucleophile tuaj yeem tawm tsam los ntawm ob sab. Raws li qhov tshwm sim, ob qho tib si enantiomers tau tsim nyob rau hauv ib qho SN1 cov tshuaj tiv thaiv, ua rau muaj kev sib tw sib tw ntawm ob qho tib si enantiomers.
Yuav ua li cas E2 cov tshuaj tiv thaiv ua rau muaj kev sib tw sib tw?
SN2 thiab E2 cov tshuaj tiv thaiv muaj cov khoom zoo heev. … Thaum lub SN2 cov tshuaj tiv thaiv ntawm α-carbon stereocenter yuav ua rau inversion ntawm configuration, SN1 cov tshuaj tiv thaiv ntawm ib qho chaw zoo sib xws muab ib qho kev sib npaug ntawm inversion thiab tuav. Cov nyhuv no ua rau muaj kev sib xyaw ua ke racemic mix
Koj paub li cas yog nws Sn2 lossis E2?
Tus kheej ntawm nucleophile lossis lub hauv paus kuj txiav txim siab seb qhov twg yog qhov nyiam. E2 cov tshuaj tiv thaiv xav tau cov hauv paus muaj zog SN 2 cov tshuaj tiv thaiv xav tau cov nucleophiles zoo. Yog li ntawd ib tug zoo nucleophile uas yog lub hauv paus tsis muaj zog yuav nyiam SN2 thaum lub cev tsis muaj zog nucleophile uas yog lub hauv paus muaj zog yuav nyiam E2.
