a. The carbonyl group of an amide is less reactive towards nucleophilic substitution reactions because of the so-called amide resonance interaction of nitrogen lone pair (RC=ONR’2 → RC- ON R2). (Relative reactivities of carbonyl compounds, increasing reactivity: nitriles < amides < esters, acids << ketones < aldehydes < acid chlorides.) However, the amides formed from imidazole (N- acylimidazoles) are highly reactive, and can be used to deliver acyl groups in much the same way as "active" esters, acid anhydrides and acid chlorides. An advantage to using N-acylimidazoles is that the imidazole that is released serves a base so additional base does not need to be added. Imidazole amides have been used in peptide and nucleoside chemistry to attach -amino acid residues to alcohols and amines. Using N-propanoylimidazole and N,N-dimethylpropanamide as examples explain why the imidazole amide is a good acylating agent.
a. The carbonyl group of an amide is less reactive towards nucleophilic substitution reactions because of the so-called amide resonance interaction of nitrogen lone pair (RC=ONR’2 → RC- ON R2). (Relative reactivities of carbonyl compounds, increasing reactivity: nitriles < amides < esters, acids << ketones < aldehydes < acid chlorides.) However, the amides formed from imidazole (N- acylimidazoles) are highly reactive, and can be used to deliver acyl groups in much the same way as "active" esters, acid anhydrides and acid chlorides. An advantage to using N-acylimidazoles is that the imidazole that is released serves a base so additional base does not need to be added. Imidazole amides have been used in peptide and nucleoside chemistry to attach -amino acid residues to alcohols and amines. Using N-propanoylimidazole and N,N-dimethylpropanamide as examples explain why the imidazole amide is a good acylating agent.
Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
Related questions
Question
please help with part B:
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 3 steps with 3 images
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.Recommended textbooks for you
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY