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23 Cards in this Set
- Front
- Back
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Rate of reaction for Sn2?
Stereochemistry of Sn2? Number of steps Sn2? |
Rate=K[nuc][R-LG]
Inversion of Stereochemistry One step (nuc attacks and LG leaves simultaneously) |
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Mechanism of E2
Configuration of bond for E2 |
Base attacks beta-H electrons move to form double bond
Configuration dependent on alignment (beta-H trans or cis to LG) |
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What happens if there is more than one beta-H for E2?
What happens if there is more than one beta-C for E2? |
Both stereochemistries
the more substituted beta-C has its hydrogen removed because it is better at delocalizing the charge of the carbocation |
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Sn1 vs. E1
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LG leaves in both leaving a carbocation and LG-
Sn1 Racemic mix of attached nucleo (different stereo) Eq E double bond plus Z diasteriomer |
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1* with....
Good nuc, weak base Poor nuc, protic solvent Strong base unhindered Strong base |
Sn2
Slow Sn2 Sn2/E2 E2 |
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2* with....
Good nuc, weak base Poor nuc, protic solvent Strong base unhindered Strong base |
Sn2
Slow Sn1 E2(Sn2) E2 |
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3* with....
Good nuc, weak base Poor nuc, protic solvent Strong base unhindered Strong base |
Sn1
Sn1/E1 E2 E2 |
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What are good nucleophiles but weak bases?
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P, N, S, N3, Cn, I
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WHat are protic solvents?
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ROH, H20 has NH or OH bonds
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What is a strong base unhindered
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OH-
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What is an example of a big strong base
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tBuO
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What mechanism does heat favor?
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Elimination
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How can you speed up Sn1/E1
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Polar protic solvents (stabilization of the carbocation)
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Reagent: H30+ or H20/H2SO4
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E/N: H/OH
Regioselectivity: Markonikov Stereoselectivity: C-->not stereo enantiomer (1 chiral) |
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Reagent: H-X
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E/N: H/X
Regioselectivity: Markonikov Stereoselectivity: C+ intermediate enantiomer (1 chiral) |
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Reagent: 1) BH3 2)NaOH,H202, H20
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E/N: H/OH
Regioselectivity: Anti-Markonikov Stereoselectivity: syn enantiomer (2 chiral) |
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Reagent: KMnO4 or OsO4
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E/N: OH/OH
Regioselectivity: None Stereoselectivity: syn enantiomer |
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Reagent: R-C=O-OOH
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E/N: O
Regioselectivity: None Stereoselectivity: None enantiomer; 2C+O triangle |
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Ozone
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E/N: O/O
Regioselectivity: None Stereoselectivity: None Ph-H3C-C=O + H(or OH if H2O2 reagent)-C-H3C=O |
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H2/Pt
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E/N: H/H
Regioselectivity: none Stereoselectivity: syn |
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X2/H2O
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E/N: X/OH
Regioselectivity: Markonikov Stereoselectivity: anti enantiomer |
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X2
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E/N: X/X
Regioselectivity: None Stereoselectivity: anti enantiomer |
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X2/ROH
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E/N: X/OR
Regioselectivity: Markonikov Stereoselectivity: anti enantiomer |
