In: Chemistry
What will be the product of a nucleophilic acyl substitution reaction−a new carboxylic acid derivative, a mixture of two carboxylic acid derivatives, or no reaction−if the new group in the tetrahedral intermediate is
1. a stronger base than the substituent that was attached to the acyl group?
a.a new carboxylic acid derivative
b.a mixture of two carboxylic acid derivatives
c. no reaction
2. a weaker base than the substituent that was attached to the acyl group?
a.a new carboxylic acid derivative
b.a mixture of two carboxylic acid derivatives
c. no reaction
3. similar in basicity to the substituent that was attached to the acyl group?
a.a new carboxylic acid derivative
b.a mixture of two carboxylic acid derivatives
c. no reaction
1. If the new group (nucleophile) is a stronger base than the substituent on the acyl group, then A new carboxylic acid derivative will form.
for example : Acyl halides can be substituted by stronger bases like NH2- in nucleophilic acyl substitution to form amides.
2. If the new group (nucleophile) is a weaker base than the substituent on the acyl group then there will be No reaction. Since weak bases are better leaving groups, after forming the tetrahedral intermediate, the new group (nucleophile) will leave again and we will get the same (original) acyl product.
for example : Amides can not be substituted by weaker bases like Cl- in nucleophilic acyl substitution.
3. If the new group (nucleophile) is similar in basicity than the substituent on the acyl group then there will be A mixture of two carboxylic acid derivatives.
for example : Carboxylic acids after a nucleophilic acyl substitution reaction.by OR- can form Esters and be in a mixture.