organic_chemistry_sn2_sn1_e2_e1 - organic chemistry: SN2,...

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organic chemistry: S N 2, E2, S N 1, E1 S N 2 E2 S N 1/E1 S N 1 and E1 have identical rate determining steps, so they generally occur simultaneously and have the same properties. S N 2 and E2 S N 1/E1 mechanism one step—this single step is the rate-determining step (RDS) two steps—RDS is formation of carbocation big obstacle S N 2: steric hindrance blocking Nu (Nu is in RDS) E2: blocking B isn’t a big obstacle (B doesn’t join substrate) stabilizing carbocation (Nu/B isn’t in RDS, so blocking it isn’t an obstacle) stereo- chemistry S N 2: inversion (backside attack, since LG blocks frontside) E2: cis vs. trans determined by anti-periplanar transition-state S N 1: racemization (planar carbocation intermediate) E1: both cis and trans isomers will be produced regio- chemistry E2: possible products from deprotonation of any β -carbon major product w/ bulky base: less substituted (steric hindrance) major product with non-bulky base: more substituted E1: possible products from deprotonation of any β - C major product: more substituted alkene (e - -donating alkyl substituents stabilize alkenes) rate expression Rate = k [substrate] [Nu - or B - ], so [Nu - /B - ] rate (substrate and Nu - /B - are in RDS) Rate = k [substrate], so [Nu - /B - ] rate unchanged (only the substrate is in RDS) Nu quality requires good Nu/strong B (Nu/B is in RDS) bulky Nu/B favors E2 vs. S N 2 (blocking B isn’t a big obstacle) can work with a poor Nu/weak B (Nu/B isn’t in RDS) LG quality requires good leaving group (because leaving group is in RDS) requires good leaving group (because LG is in RDS) preferred solvent? polar aprotic (no O-H or N-H bonds)
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organic_chemistry_sn2_sn1_e2_e1 - organic chemistry: SN2,...

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