In Situ Formed N-Sulfonyl Guanidinium for Efficient Amide Coupling

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Medicinal Chemistry

Background:

• Amides are fundamental building blocks in chemistry and biology.
• Efficient and practical amide synthesis methods are highly sought after.
• Existing methods may suffer from harsh conditions, low yields, or epimerization.

Purpose of the Study:

• To develop a novel, effective, and practical method for amide and peptide synthesis.
• To utilize an inexpensive and robust coupling reagent for carboxylic acid and amine reactions.

Main Methods:

• In situ generation of N-sulfonyl guanidinium using 2-(tert-butyl)-1,1,3,3-tetramethylguanidine and trifluoromethanesulfonic anhydride.
• Formation of carboxylic acid-sulfonic acid mixed anhydrides.
• Subsequent reaction with amines at room temperature, facilitated by the guanidinium reagent.

Main Results:

• The N-sulfonyl guanidinium reagent efficiently couples carboxylic acids and amines.
• Amides and dipeptides are synthesized in excellent yields.
• The method demonstrates minimal epimerization during peptide synthesis.

Conclusions:

• The developed protocol offers a novel and useful strategy for synthesizing amides and peptides.
• The use of in situ generated N-sulfonyl guanidinium provides a robust and practical coupling system.
• This method is suitable for room temperature synthesis, preserving stereochemical integrity.