lecture 6 Flashcards
can a phenol react with Br2 without it being activated
yess!
how does a phenol react with a Br2 without it being activated (step 1)
the lone pair on OH forms a double bond
the double bond goes to the single one
the double one then attacks one of the Br2
how does phenol react with Br2 without being activated (step 2)
the H next to the Br then makes a double bond
the double bond makes another double bond
the double bond to the O neutralises the OH
what is the product of phenol and Br2 without activation
para bromo phenol
4 bromo phenol
what must happen,, and what is repeated in order for Br2 to be added to phenol
the O lone pair is transported in order for a double bond to attack the Br2
then the H is removed and it’s e- are transported back towards the O in order to neutralise it
how many times can a phenol react with a Br2 without it needing activation
2,4,6-tribromophenol
OH is what directing…
it’s para directing
the Br is moved to the para and ortho positions
what is the friedel crafts acylation reaction
an acyl chloride + AlCl3
what happens in an friedel craft acylation
the acyl chloride is activated using AlCl3
(Cl attacks AlCl3,,, the AlCl4 is removed and gives R-C=O (acylium ions + it’s resonance forms)
what happens once the alkyl chloride is activated
it forms an acylium ion
this can be attacked by a nucleophile
how does the acylium ion and benzene react
double bond attacks the acylium ion C+
the H in benzene is then removed in order to regain its aromaticity
when a group is added to benzene it always has….
resonance structures
bc it has a +
and it has lost its aromaticity
can a Carbon act as an electrophile
yes!!
if the carbon is +
how can we form a Carbon Electrophile
react H+ with tert butanol
the OH attacks the H+
forms H2O
water is lost as a good LG
a CC+ is formed
benzene and CC+ reacts to giveee
3 resonance structures bc it loses aromaticity
then a H is removed
and tert butyl benzene is formed
