Ch. 18 B, Exam 1 Reactions: Write the Reagents

Resonance Effects

Orbital overlap with p character

Inductive Effects

Bond polarization

Meta

How to EWG direct?

Ortho/Para

How to EDG direct?

Ortho/Para

How to Halogens direct?

The better activator takes priority

What if two groups do NOT direct to the same location?

Between two meta substituents

Where can you not add?

Deactivators

Are EWG activators or deactivators?

Deactivators

Are halogens activators or deactivators?

Activators

Are EDG activators or deactivators?

They are good Nu's, so they react more quickly

Why are EDG good activators?

Nucleophilic Aromatic Substitution

Nucleophile replaces leaving group on aromatic ring

NAS Addition-Elimination (SNAR)

1. Ring must have a strong EWG 2. Ring must have a LV 3. LV must be O/P to EWG

What are the three things there must be for SNAR to occur?

NAS Elimination-Addition (Benzyne)

NAS Addition-Elimination (SNAR) reagents

NaOH

NAS Elimination-Addition (Benzyne) Reagents

1. NaNH2, NH3

2. H3O+

NAS (SNAR and Benzyne)

Which set of aromatic substitution reactions do we not need to worry about directing effects?

X2, FeX3

HNO3, H2SO4

SO3, H2SO4

RX, AlX3

RC(=O)X, AlX3

H2SO4, H2O

H2, Ni

H2, Pd

Na, CH3OH, NH3

*Edg - NOT reduced

* Ewg - reduced

NBS

*adds Br to benzylic carbon

H2O

*Can do other subs/elim rxns

Na2Cr2O7, H2SO4, H2O

*will only oxidize at benzylic carbons that have H's

1. NaH

2. RX

*Williamson ether synthesis

* adds R to the O

H2SO4, ROH

*Acid Cat addition to alkenes (makes an ether)

*Adds OR markov

* May have C+ rearrangement

1. Hg(OAc)2, ROH

2. NaBH4

*Alkoxymercuration-demerc

*Adds OR markov

H2SO4, mild heat

*Acid-cat dehydration

*makes a symmetric ether

1. Strong Nu

2. H3O+

*Epoxide rxn

*Attacks LEAST subs C

* Adds R to least subs C

H2SO4, ROH or just HX

*Epoxide rxn

*Attacks MOST subs C