Activated Synthons for Faster Azapeptide Bond Formation
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Solution Overview
Problem
Existing azapeptides and aza-amino acid conjugates face challenges in synthesis due to slow peptide bond formation, enzymatic stability, and the formation of unwanted side products, with conventional coupling agents being inefficient and costly.
Innovation Solution
Development of compounds of Formula (IA) and (IB) that include N-phthalimidyl or NR1R2 groups, heteroaryl substituents, and specific side chain radicals, which serve as building blocks for synthesizing azapeptides and peptidomimetics, enhancing stability and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional coupling agents are used for azapeptide synthesis, then the synthesis can proceed with standard reagents, but the reaction rate is slow and unwanted side products are formed
Solution Approach 1:
The patent changes the chemical parameters by using activated esters ( NHS esters, hydroxysuccinimide esters, pentafluorophenyl esters) instead of conventional carboxylic acids. This activation transforms the poor leaving group (OH-) into excellent leaving groups, dramatically increasing the electrophilicity of the carbonyl carbon and accelerating the amide bond formation rate while reducing side reactions
Solution Approach 2:
The patent introduces activated ester intermediates as mediators between the carboxylic acid and amine. These activated esters serve as highly reactive intermediates that facilitate the coupling reaction by providing a better leaving group, thereby increasing both reaction rate and selectivity while minimizing side product formation
2Reliability
If aza-amino acids are used as synthons, then azapeptides can be synthesized with improved metabolic stability, but the carbonyl moiety reactivity is reduced leading to slower bond formation
Solution Approach 1:
The patent changes the reactivity parameter of the aza-amino acid carbonyl group by converting it to an activated ester. This transformation increases the electrophilicity of the carbonyl carbon despite the electron-withdrawing nature of the adjacent nitrogen, enabling fast amide bond formation while preserving the metabolic stability benefits of the aza-peptide bond
3Ease of manufacture
If conventional peptide synthesis methods are used, then standard amino acids can be employed, but enzymatic degradation occurs at higher rates
Solution Approach 1:
The patent segments the peptide backbone by replacing individual α-carbon atoms with nitrogen atoms to create aza-amino acid residues. This segmentation disrupts the recognition patterns of proteolytic enzymes while maintaining the overall peptide structure and function, thereby improving enzymatic stability
Solution Approach 2:
The patent creates composite structures by combining conventional amino acid residues with aza-amino acid residues in the same peptide chain. This composite approach allows retention of biological activity from natural amino acids while incorporating enzymatic stability from aza-amino acid segments
4Manufacturing precision
If two nitrogen atoms in the hydrazine system are both functionalized, then complete azapeptide structure can be formed, but orthogonal functionalization becomes difficult
Solution Approach 1:
The patent applies preliminary protection to one nitrogen atom with a protecting group before functionalizing the other nitrogen. This preliminary action allows selective functionalization of the unprotected nitrogen while the protected nitrogen remains inert, simplifying the synthesis pathway and avoiding complex orthogonal functionalization requirements
Data Source
AI summary
Synthesis of O-benzotriazole and O-imidazole synthons are described. Uses of synthons in synthesis of azapeptides and other peptidomimetics, azapeptides and other peptidomimetics synthesized from the synthons and uses of azapeptides and other peptidomimetics are also described.