Strong Nu and Base: Primary
E2 minor
SN2 major
Strong Nu and Base: Primary exception
the use of a bulky base causes a flip in major and minor products
Strong Nu and Base: Secondary
E2 major
SN2 minor
Strong Nu and Base: Tertiary
E2 only
Strong Nu and Base examples
RO-
HO-
Weak Nu and Base: Primary
No reaction
Weak Nu and Base: Secondary
SN1 only or E1 only
Weak Nu and Base: secondary with H2S or HSR
SN1 only
Weak Nu and Base: Secondary with H2SO4
E1 only
Weak Nu and Base: Tertiary
E1
SN1
Weak Nu and Base: E1 Rxns are favored with
Heat
Base only (ex. H-, DBU)
E2 only
Nu Only (ex. X-, sulfur containing)
SN only based on tertiary, secondary or primary
SN2 nucleophile type
Nu-
SN2 preference for 3,2,1
1,2
SN2 stereochemistry
inversion
SN2 solvent of choice
aprotic
SN1 nucleophile type
Nu-H
SN1 preference for 3,2,1
3,2
SN1 stereochemistry
racemic loss of stereochemistry
SN1 solvent of choice
protic
E2 preference for 3,2,1
3>2>1
E2 major and minor products
Zaitsev>Hofmann
Zaitsev products
more substitutions
Hofmann products
less substitutions
E2 cis vs trans preference
trans
E2 base preference
strong B
Antiperiplanar
B-H and LG are 180 degrees apart for E rxn to occur
E1 preference for 3,2,1
3,2
E1 cis vs trans preference
trans
E1 major and minor products
Zaitsev always wins
E1 base preference
Weak B
E2 steps
1 step concerted
E1 steps
2 step process
More substituted= ??? stability
more (through delocalization)
E confirmation means
opposite sides
Z confirmation means
together
E/Z confirmation found by ranking
atomic number on either side of the double bond
Multiple double bonds naming suffix
-adiene
Strong Base with Weak Nu
E2
Weak Base with Strong Nu
SN2
2 examples of Strong Base with Weak Nu
DBU
H+
2 examples of Weak Base with Strong Nu
X-
-SH
Hydrohalogenation (Markovnikov) solvent
HX
Hydrohalogenation (Markovnikov) halogen addition
to more substituted side
Hydrohalogenation (Anti-Markovnikov) solvent
HX, ROOR
Hydrohalogenation (Anti-Markovnikov) halogen addition
to less substituted side
Acid-Catalyzed Hydration solvents (3)
H3O+
H20/H2SO4
dilute H2SO4
Acid-Catalyzed Hydration reaction rate vs. branching
tertiary is fastest
Acid-Catalyzed Hydration additions
H-OH
Acid-Catalyzed Hydration addition type
Mark
Draw Mechanism for Acid-Catalyzed Hydration
...
Oxyurcuration-demurcuration solvent
Hg(OAc)2, H2O/NaBH4
draw Oxyurcuration-demurcuration first step
...
Oxyurcuration-demurcuration addition groups
add OH to more substituted side
Hydroboration-oxidation solvent
BH3 THF/H2O2, NaOH
Hydroboration-oxidation addition type
syn
Hydroboration-oxidation forms which Mark product
Anti
Hydroboration-oxidation addition groups
OH-H
Hydrogenation solvent
H2/Pt
Hydrogenation addition groups
H-H
Hydrogenation addition type
syn
3 Chiral center trends with Hydrogenation
0-no new stereochemistry
1-racemic mix
2-pair of enantiomers
Wilkinson's catalyst is used for
Hydrogenation
Purpose of Wilkinson's catalyst
have an even mixture since Wilkinson's catalyst is homogeneous
Asymmetric Hydrogenation solvent
Wilkinson's catalyst
Asymmetric Hydrogenation addition groups
H
Chiral catalysts (2) for Asymmetric Hydrogenation
S-BINAP
Ru(BINAP)Cl2
Halogenation solvents (2)
Br2
Cl2
why arent I and F used for halogenations?
F is too violent
I is to bulky
Halogenation addition type
anti
Halohydrin Formation solvents
Br2/H2O or H2S
Halohydrin Formation addition groups
OH-Br
Halohydrin Formation OH group gets what side?
more substituted
Halohydrin Formation addition type
anti
Anti-Dihydroxylation solvents (2)
RCO3H/H3O+
mCPBA
Anti-Dihydroxylation addition groups
2 OH to opposite sides
Anti-Dihydroxylation forms an intermediate with an
epoxide
Draw mechanism for Anti-Dihydroxylation
...
Syn-Dihydroxylation solvents (2)
OsO4/NMO or NaHSO3
KMnO4/NaOH cold
Syn-Dihydroxylation addition groups
2 OH on same side
Draw Mechanism for Syn-Dihydroxylation
...
Better solvent with OsO4, why?
NMO, it is catalytic
Ozonolysis Solvent
O3/DMS
Ozonolysis breaks
alkene bonds
Ozonolysis adds
double bonded O to the ends of the new products
Draw Mechanism for Hydrohalogenation (Mark)
...
Draw Mechanism for Acid-catalyzed rxn
...
Draw Mechanism for Bromination
...
Draw Mechanism for Halohydrin Formation
...
Four types of arrow pushing mechanisms
Proton Transfer
Loss of LG
Carbocation Rearrangement
Nucleophilic Attack