The major product of a monosubstituted benzene ring with an electron withdrawing group and an additional electrophile is a product with meta substitution. In contrast to electron donating groups,
electron withdrawing groups are deactivating
.
Are activating groups electron withdrawing?
Electron donating groups are typically divided into three levels of activating ability (The “extreme” category can be seen as “strong”.)
Electron withdrawing groups are assigned to similar groupings
. Activating substituents favour electrophilic substitution about the ortho and para positions.
Is deactivating or activating group?
Substituted rings are divided into two groups based on the type of the substituent that the ring carries: Activated rings: the substituents on the ring are groups that donate electrons. Deactivated rings: the substituents on the ring are groups that withdraw electrons.
What makes a group electron withdrawing?
Electron withdrawing group (EWG): An atom or group
that draws electron density from neighboring atoms towards itself
, usually by resonance or inductive effects.
Are methyl groups activating or deactivating?
Thus, the methyl group is
an activating group
. All activating groups are electron-donating groups.
Which is the strongest electron withdrawing group?
- Nitro groups (-NO
2
) - Aldehydes (-CHO)
- Ketones (-C=OR)
- Cyano groups (-CN)
- Carboxylic acid (-COOH)
- Esters (-COOR)
Is methoxy an electron withdrawing group?
b) -OCH3 (methoxy group) The methoxy group is
electron withdrawing
by the inductive effect of the oxygen atom, since the electronegativity of oxygen is 2.6.
Is OCH3 a deactivating group?
Common activating groups (not a complete list): Alkyl, NH2, NR2, OH, OCH3, SR.
Common deactivating
groups (not a complete list): NO2, CF3, CN, halogens, COOH, SO3H.
Is CH3 a deactivating group?
As we just saw, CH
3
is a perfect example of an activating group; when we substitute a hydrogen on benzene for CH
3
, the rate of nitration is increased. A deactivating group, on the other hand,
decreases the rate of an electrophilic
aromatic substitution reaction, relative to hydrogen.
Is a deactivating group?
If
electrophilic aromatic substitution of a monosubstituted benzene is slower than that of
benzene under identical conditions, the substituent in the monosubstituted benzene is called a deactivating group. All deactivating groups are electron-withdrawing groups. …
What are examples of electron-withdrawing groups?
Electron withdrawing groups have an atom with a slight positive or full positive charge directly attached to a benzene ring. Examples of electron withdrawing groups:
-CF
3 , –
COOH, -CN
. Electron withdrawing groups only have one major product, the second substituent adds in the meta position.
Is an OH group electron-withdrawing?
OH is
an electron donating group
. … Electron withdrawing groups have an atom directly attached to a benzene ring with a slight positive or full positive charge. Examples of groups that withdraw electrons: -CF
3
, -COOH, -CN.
Are aryl groups electron-withdrawing?
C6H5
is the aryl group corresponding to benzene. It is most commonly known as phenyl. It is known to be an electron withdrawing group.
Which is more activating OH or OCH3?
OCH3 group is more electron withdrawing
(i.e, shows more -I effect) than the OH group. Explanation: The reason is that, there are two lone pairs of oxygen. Oxygen has a smaller size, so in case of OCH3, the methyl group is close to the lone pair electrons, which leads to Steric repulsion.
Is ortho or para more stable?
Here, we are being asked to compare the stability of the para and ortho hydrogen. … – These two forms of molecular hydrogen are also referred to as spin isomers. – Now, due to antiparallel spin arrangement, para hydrogen has less energy and thus,
they are more stable than ortho hydrogen
.
Is Oh op directing?
since OH is +R/+M group thus provides e- to the benzene ring thus creates +ve charge on meta position and -ve charge on ortho and para position thus it is
ortho para directing group
…
