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35 Cards in this Set
- Front
- Back
nucleophile
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good nucleophile is strong base
e- rich species that are attracted to positively polarized atoms nucleophile strength RO-> HO->RCO2>ROH>H2O |
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electrophile
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gets attacted by nucleophile
partially positive C attacted to electronegative atom |
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nucleophiles in protic solvent
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solvent that capable of hydrogen bonding
large atoms tend to be better nucleophile CN->I->RO->HO->Br->Cl->F->H2O |
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nucleophiles in aprotic solvnet
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F->Cl->Br->I
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SN1
unimolecular nucleophilic sub |
-2 steps
-favored in protic solvent -formation of carbocation (rate limiting step) -rate=k[RX] RX=leaving group -favors 3>2>1 carbon because this is order of stability for carbocation more stable faster the rxn -produce recemic product have equal amt of R and S thus no optical activity -favored with bulky nucleophiles |
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good leaving group
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weak base makes good leaving group
toslate>I-> Br-> Cl- > F- |
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SN2
bimoecular nucleophillic sub |
-1step
-favor aprotic solvent -favor 1>2>3 carbon -rate k[nuc][RX] -produce inverted product optically active -trigonal bypyramid transition state |
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trigonal bypyrimid transistion stae in which sub model?
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SN2
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strong nucleophile
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CN>I->RCO2>RO->HO->Br>Cl->F->H2O
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strong acid
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HCl, H2SO4, H3PO4, HNO3
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weak acid
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Cl-, SO4-, PO4-, NO3-
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toslate
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good LG
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Br
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good LG
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Cl
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good LG
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HCl
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strong acid
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H2SO4
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Strong acid
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H3PO4
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Strong acid
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HNo3
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Strong acid
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CN>I>RO>HO>Cr>Cl>F>H20
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nucleophile in protc solution
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F>cl>Br>I
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nucleophile in aprotic solution
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radicals
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species with unpaired electron
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what is most stable radical
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CR3 > CR2H> CRH2> CH3
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free radical halogentation rxn are practical only fo () and ()
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br and cl
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in free radical halogentaion rxn Br react () compared to cl
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slowly thus more likely to react in a manner that forms most stable alkyl radical
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in free radical halogenation
Cl indiscriminates and produce |
several different both stable and nonstable alkyl radical
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RO-
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weak nucleophile
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NH3
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weak nucleophile
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aprotic is needed in SN2 bc
how does H bond affect nu- in in protic during SN1 |
no H-bond means Nu- naked and free to atack electrophile(rate det. step)
in SN1 protic, Hbond works with Nu- but less then SN2 bc Nu is not in rate det. step |
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OH-
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strong nuceophile
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CN-
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strong nucleophlile
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NH2-
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strong nucleophile
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vinylic proton
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proton that is attach to the double bond
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alcohol and strong acid like H2SO4 lead to
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elimination
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strong base with
3, 2, 1, alklyl halide |
3- E1
2- E2 1- E2/Sn2 |
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weak base with
3, 2, 1, alklyl halide |
3-Sn1/E1 in protic
2-Sn2 in aprotic 1-Sn2 |