The key difference between O acylation and N acylation is that O acylation forms an oxygen-containing final product whereas N acylation forms a nitrogen-containing final product.
Acylation is the chemical process adding an acyl group to a chemical compound. In this process, the compound which provides the acyl group is called the acylating agent. An acyl group has the chemical formula R-C(=O)- where R is either an aryl or an alkyl group. According to the final product of acylation, there are three major acylation processes as C acylation, O acylation and N acylation. This article discusses O acylation and N acylation reactions.
CONTENTS
1. Overview and Key Difference
2. What is O Acylation
3. What is N Acylation
4. Side by Side Comparison – O Acylation vs N Acylation in Tabular Form
5. Summary
What is O Acylation?
O acylation is a type of acylation process in which the final product contains an oxygen atom connecting the acyl group to the reactant compound. In other words, there is an oxygen atom between the acyl group and the reactant compound’s moiety. O acylation is a type of nucleophilic acyl substitution reaction. For this process, the acylating agent is usually acyl chloride or acyl anhydride. This type of acylation occurs with the reactant molecules containing –OH groups such as aryl or alkyl alcohols.
Figure 01: A Typical Acylation Process
What is N Acylation?
N acylation is a type of acylation in which the final product contains a nitrogen atom, connecting the acyl group to the reactant compound. In other words, there is a nitrogen atom between the acyl group and the reactant compound’s moiety.
Figure 02: Mechanism of an N Acylation Reaction
N acylation is a type of electrophilic acylation substation reaction. For this process, the acylating agent is usually acyl chloride or acyl anhydride. This type of reactions occurs with the reactant molecules containing –NH groups such as aniline. For example, N acylation of aniline is an efficient route when acetic anhydride is used as the acylating agent.
What is the Difference Between O Acylation and N Acylation?
According to the final product of the acylation process, there are three major acylation processes as C acylation, O acylation and N acylation. O acylation is a type of acylation process in which the final product contains an oxygen atom, connecting the acyl group to the reactant compound, while N acylation is a type of acylation in which the final product contains a nitrogen atom, connecting the acyl group to the reactant compound.
Therefore, the key difference between O acylation and N acylation is that O acylation forms an oxygen-containing final product whereas N acylation forms a nitrogen-containing final product. The reactants that undergo O acylation reactions are –OH group-containing compounds such as phenols. The reactants that undergo N acylation are the compounds containing –NH groups such as aniline. Moreover, O acylation is a type of nucleophilic acyl substitution reaction while N acylation is a type of electrophilic acylation substation reaction.
The following infographic summarizes the difference between O acylation and N acylation in tabular form.
Summary – O Acylation vs N Acylation
According to the final product of the acylation process, there are three major acylation processes as C acylation, O acylation and N acylation. The key difference between O acylation and N acylation is that O acylation forms an oxygen-containing final product whereas N acylation forms a nitrogen-containing final product.
Reference:
1. Ouarna, Souad, et al. “An Eco-Friendly and Highly Efficient Route for N-Acylation under Catalyst-Free Conditions.” Oriental Journal of Chemistry, 20 June 2015, Available here.
2. Hunt, Ian. “Ch24 – Acylation of Phenols.” Department of Chemistry, University of Calgary, Available here.
Image Courtesy:
1. “Acylation Friedel-Crafts” By Prepapc – Own work, CC BY-SA 3.0) via Commons Wikimedia
2. “Mechanism of N-acylation using HATU” By Dar58 at English Wikipedia, CC BY-SA 3.0) via Commons Wikimedia