Chapter 19 Flashcards Preview

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Flashcards in Chapter 19 Deck (50):
1

electrophilic aromatic substitution

aromatic proton is replaced by electrophile
adding iron to reaction, causing the addition of halide

2

Halogenation

feBr3 reacts with Br2 to form complex that acts as Br+
aromatic ring is nucleophile and attacks electrophile to prodice sigma complex

3

Halogentation - product

produces aromatic ring with addition of a halide

4

Halogenation - reagants

FeBr3
Br2
or
ALBr3
Br2

5

Sulfonation - reagants

fuming H2sO4

6

sulfonation - products

aromatic ring + SO3H

7

sulfonation - concentrated fuming H2SO4

creates aromatic ring + SO3H

8

Sulfonation - dilute H2SO4

goes from aromatic ring + SO3H to benzene

9

Nitration - reagants

HNO3
H2SO4

10

Nitration - products

produces aromatic ring with NO2

11

To produce amino

once NO2 is added to ring, can be reacted to form NH2

12

To produce amino - reagants

Fe or Zn
HCl

13

Friedel craft akylation - reagants

halogenated akyl halide
AlCl3

14

Friedel craft akylation - carbocation structure

cant use primary, they will undergo rearrangement to form secondary or tertiary

15

Friedel craft akylation - products

addition of carbon chain on benzene

16

Friedel craft akylation - efficiency

can use substrates that undergo rearrangement

17

Friedel craft akylation - alkyl halide used

carbon connected to the halogen must be sp3
vinyl and aryl carbocations arent stable to form under friedels craft

18

Friedel craft akylation - installation of alkyl

activates ring to further alkylation
polyalkyations usually occurs

19

Friedel craft akylation - uncompatable groups

certain groups like nitros are incompatable

20

Friedel craft acylation - product

benzene with R group
R-C=O(Cl) group
aryl ketone

21

Friedel craft acylation - reagants

R-C=O(Cl) group
AlCl3

22

acylium ion

formed from removal of leaving group of R group
resonance stable and doesnt undergo rearrangement

23

Clemmensen reduction - product

reduces ketone to carbon chain

24

Clemmensen reduction - reagants

Zn(Hg)
HCl
Heat

25

Methyl group - activating

activates ring

26

Activating groups - position of the added

ortho para, usually para to stop steric hindarance

27

Deactivating groups - position of added

meta

28

Activating groups

donates electron density to the ring
usually have electronegative negative atom
makes ring positive

29

Deactivating groups

withdraws electron density from ring
usually electronegative positive atoms
makes ring negative

30

Halogens - the exception

are ortho para even though they are deactivators

31

Strong activators

presence of lone pair adjacent from ring
with electronegative atoms
lone pair delocalises into the ring

32

Moderate Activators

have lone pair delocalised outside ring
lone pair next to ring, nut lone part participates in resonance outside ring

33

Weak activators

donate electron density by weak effect of hyperconjugation
akyl groups

34

Weak Deactivators

halogens

35

Moderate deactivators

pi bond to electronegative atom
carboxylic acids
aldehydes

36

Strong deactivators

NO2
N-R3+
C-X3

37

Directing effect

each substituents have to be placed specifically

38

Directing effect - competition

more powerful activating group dominates

39

Blocking Groups

installed in order to block the position needed

40

Blocking group - properties

must be easily removable
sulfonation is generally used as its reversible

41

Nitration - limitation

cant be performed on ring with amino group

42

Friedels craft reaction - limitation

can be accomplished on rings with moderate or strong deactivators
must be activated or weak deactivator

43

Nucleophilic Aromatic Substitution

aromatic compound is treated with strong nucleophile which displaces leaving group

44

Nucleophilic Aromatic Substitution - reagants

NaOH 70 degrees
H30+

45

Nucleophilic Aromatic Substitution - criteria

ring must have powerful deactivator
must have leaving group
leaving group must be ortho or para to deactivator

46

Elimination - Addition - products

produces benzene ring with new
compound

47

Elimination addition - reagants

NaOH
H3O+
Heat

48

Elimination addition - reagants - low temps

NaNH2 NH3(l)
H3O+

49

Bromination

adds bromine

50

Bromination reagents

NBS
CCl4