Critical role of Bronsted acid in Lewis-acid-catalyzed synthesis of Amadori and Heyns compounds of β-amino acids

Abstract

Amadori and Heyns rearrangement reactions are a century old reactions of the carbohydrates. The great body of literature on these reactions are concentrated on ɑ-amino acids. Reports on the synthesis and chemistry of Amadori and Heyns compounds derived from β-amino acids are scarce. We demonstrate herein, via Lewis-acid catalysis, synthesis of Amadori and Heyns compounds derived from β-amino acids consisting of β-alanine and β-phenylalanine with, D-xylose, D-galactose, D-fructose, D-mannose, D-maltose, D-lactose. The accomplished Lewis-acid catalyzed method is practical and devoid of separation techniques for achieving purity. We also report insight on the mechanism of Lewis-acid catalyzed Amadori and Heyns rearrangement reactions, and reveal the key role of Bronsted acid in Lewis-acid catalyzed Amadori and Heyns synthesis of β-amino acids.

Graphical Abstract

Key words:

• Amadori reaction
• Heyns reaction
• β-amino acids
• Lewis acid
• Bronsted acid
• Catalysis

Acknowledgment

We acknowledge support and facilities extended by Dr. Sridevi A. Singh, Director, CSIR-CFTRI for the execution of the work. Nanishankar V.Harohally specially thank his first guru Nagarathnamma Hosakote for the help extended during the course of the work.

Author contributions

Debasree Chanda and Gangothri M. Venkataswamy contributed equally for this paper.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by DST-WOS A grant awarded by DST, New Delhi.