Replacement by Hydroxyl Group and Electrophilic Substitution Reactions Video Lecture - JEE

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alkanes and hollow areas part where e8
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we will see that by adding some electron
withdrawing row we will see that the
arrange hello Aries are more reactive
so if we add electron withdrawing group
and that to Ed ortho and para position
we'll discuss this wife at also and para
position right so it increases the
reactivity towards nucleophilic
subjection increases react because
electron withdrawing to well take
electrons by little decrease the
electron density so the nucleophile is
one which has more electrons is already
electron rich
so the my compound is not electron rich
can attack for example I'll show you
this particular compound if I have I
have a chlorine here the one earlier one
the same one I have seen for the same
reaction as sy it was a hints
chlorobenzene I had to add NaOH 623
Kelvin right and then 300 atmospheres
sure your form so now correct this
bigger reaction we have seen very - your
condition now you see that if I add my
guru here at para position the same
reaction you again need anywhere h right
but now you need only 443 can we get the
same substitution reaction here my CL
will be replaced with H and when I
trouble be here
you put one more nitro group here so
what you will observe here is this all
experimental values so you put one mona
intro here so what we have seen
experimentally is any o h it needs less
a temperature 6 v 68 film in you give or
replacement reaction solution reaction
as this becomes H whose N or - this is a
- a little pond ring let me add one more
- here this is what experiment Li has
been seen that is a chlorine here this n
not to use no.2
this is no.2 so this needs for the less
temperature just you need to just vomit
almost you can say she had a killer you
get the substitution reaction now you
have seen that we added my true group
only add ortho and para much right then
toward this electron withdrawing rule
will withdraw electron and it will
become less electron rich and then
nucleophile can attack it because it is
manipulative can attack correct this
carbon now the question is why did we
add only ad ortho and para version not
another version think so let's see right
so we have seen that end of the group is
only ortho position nor that meta
position Y so let's first draw normal
hello Ari let's see what is there in
that if I can find something in that so
we have drawn this couple of times let
me draw this once again I have a
chlorine with our always compares so
with this this will give electron here
if you come here you form a double bond
right so it will form a double bond here
the positive charge negative charge here
and this is the bar more reasoning
structure you want you can make it this
way so this bond break we have negative
charge here this positive it will come
and cost you nearly power bond this is
born here it is a double bond it's again
to this this make this
correct this is a negative charge here
so if you see here the negative charge
is at ortho position para position or
solution so what we have seen is this
halogen item right
they also deactivate the ring as I told
right but there are two and pair right
so with the halogen attack we see the
electron density is more at ortho and
para position right so for hello alkene
hello I mean actually electron density
is more at or 20 so this is right this
is one guy this is one let's suppose one
person who has more money at these
position right so if I attach salmon are
is a thief attack these position ortho
and para position then the thief will
get more electrons right more money
electrode is like money electron is
money and as I told if my compound is
bigger is not having much money then the
nucleophile can tie because nucleophile
has lot of money Nicola find this half
of money he's had a lot of charge right
negative charge so I want to make this
guy more poor so I know that this
particular hollow ring keeps more money
and ortho and para position right
so my no.2 is nothing but electron
withdrawing rule they are thieves
they steal money so if I attach the
thieves at these position where this
compound is keeping money because this
compound keeps its money at ortho and
para position then I can destabilize
that I can make them V but if I attach a
thief here it won't make any sense
because thief will not find anything
here the electron will never be here
right the beta position if you see there
are no electrons
not much electrons electron density at
meta position is very less so if I want
to destabilize this part in a compound
I want to make this bigger because it is
D step light if it has less electrons it
is more reactive so you want to make
this compound beggar I have to attach
thief that is another group is electron
withdrawing group nothing but me thief I
have to attach this theme at the
position where this party like amount
keeps its money the money's electrons so
this like this compound keeps its money
in ortho and para position does if you
add electron withdrawing row or the
thieves at ortho and para para position
is as if you added meta position does
not make sense right the thief will be
they have a tea bonded in electron to
see but if you attach this thing that is
electron withdrawing group and ortho and
para position thief will get electrons
and dance this particular bond will be
devoid of electrons and will become less
electron reach and it can it is ready
for attack it is unstable correct so you
understood why at ortho and para
position only we are adding this
electron withdrawing groups or thieves
because at ortho and para position this
particular component has electron that
is money so it is good that we attach
thief or the electron withdrawing group
at these position so if you see this
hello or eans they have two things one
thing is they withdraw electrons right
so if you compare with benzene since
they withdraw electron they make it pour
electron deficient that think they make
it this is electron rich both are
electron rich but if you compare benzene
and hello or eans this is more electron
rich because this chlorine is trying to
withdraw electron so that vice it is the
you're trying to attach electrophile
here electrophile is one we are looking
for electrons right this has more
electrons so the reaction is fast this
has less electrons and reaction is
little slow correct
so hello arrange electrophilic
substitution is also slow
correct also it is or 2n pad I think so
we will see that all the substitution
will generally happen at ortho and para
position you see that hydrogen will be
substituted with let's suppose the Nitro
group or chloro group at ortho and para
positions will see that this is ortho
and para right thing we see the
reactions very soon let's understand
that you compare
hello arrange benzene the electrophilic
substitution also is slower in hello
Aries as compared to normal then see why
because the hello Orion has this halogen
group which it draws electron and make
its electron deficient right thank you
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