Why is -OCH3 more strongly activating than -CH3 in electrophilic aromatic substitution? Facts I know: 1) More the electron density in benzene ring, the faster the reaction. 2) Lone pair on -OCH3 group undergoes resonance and makes ortho-para positions electron rich, and so does -CH3 by hyperconjugation.
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. ... However, in case of OH, the H atom is comparatively much much smaller than O, so here no Steric repulsion takes place.
Is OCH3 an activator or deactivator?
Methoxy group (och3) is an electron-withdrawing group and hence is it is a deactivator .
What effect does OCH3 shows?
Here, the oxygen (in OCH 3 ) is more electronegative than carbon due to which it will show -I effect which is electron-withdrawing. On the other hand, OCH 3 will lose or release electrons through resonance showing +R effect . Resonance mainly occurs as there is only a lone pair that is present on the oxygen.
Is OCH3 a strong activating group?
Any group with decreases the rate (relative to H) is called adeactivating 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 Oh an activator or deactivator?
| Ortho-Para-Directors | Very Strong Activators -NH 2 , -NHR, -NR 2 , -OH, -O – | Moderate Activators -OR, -NH-CO-R, -O-CO-R | Weak Activators -R, -C 6 H 5 | Mild Deactivators -F, -Cl, -Br, -I |
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Is OCH3 ortho or meta?
Experiments show us that they are ortho-para directors. So the fact that they can contribute to resonance (like OCH3) is what stabilizes the ortho-para products relative to meta . The bottom line for today is that groups that can donate electrons will stabilize the intermediate carbocation, favoring ortho-para products.
Is OCH3 EWG or EDG?
Complete answer: Yes, the OCH3 is an electron withdrawing group . The oxygen atom in the OCH3 group is more electronegative than the carbon atom. Due to this reason, it will show the −I effect which is electron-withdrawing.
Is OH A +R or group?
A hydroxy or hydroxyl group is a functional group with the chemical formula -OH and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups.
Is OH withdrawing or donating?
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.
Is C CH3 3 activated?
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.
Is ortho or para major product?
When electrophilic substitution reaction takes place, and the ortho and para products are formed then among them para is considered as the major product and ortho as a minor product.
Is BR Ortho para or meta?
Some common ortho para directing groups are –Cl, -Br, -I, -OH, -NH 2 , -CH 3 , -C 2 H 5 . The group which directs the second incoming group to the meta position, is called a meta- director. For example, alkylation of nitro benzene gives m-alkylnitro benzene as major product.
Which group is OCH3?
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. This is reflected in the positive value for σm.
Is COOH electron donating or withdrawing?
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. ... This is due to the electron withdrawing group pulling away electrons from the carbon, creating an even stronger positive charge.
Which group is more powerful than CH3?
Why is -OCH3 more strongly activating than -CH3 in electrophilic aromatic substitution? Facts I know: 1) More the electron density in benzene ring, the faster the reaction. 2) Lone pair on -OCH3 group undergoes resonance and makes ortho-para positions electron rich, and so does -CH3 by hyperconjugation.
