Palladium-Catalyzed Aminocarbonylation in Solid-Phase Peptide Synthesis: A Method for Capping, Cyclization, and...

Area of Science:

• Organic Chemistry
• Peptide Chemistry
• Synthetic Chemistry

Background:

• Solid-phase peptide synthesis (SPPS) is a cornerstone of peptide research.
• Introducing N-capping groups is crucial for peptide stability and function.
• Existing methods for N-capping can be harsh or inefficient.

Purpose of the Study:

• To develop a novel, mild, and versatile method for N-capping peptides during solid-phase synthesis.
• To integrate aminocarbonylation with SPPS for efficient peptide modification.
• To explore the application of this method for diverse peptide functionalizations.

Main Methods:

• Development of a synthetic approach combining aminocarbonylation with SPPS.
• Utilizing a palladacycle precatalyst for mild reaction conditions.
• Employing a silacarboxylic acid as an in situ carbon monoxide (CO)-releasing molecule.
• Performing the reaction in a single vial for convenience.

Main Results:

• Successful introduction of N-capping groups onto solid-supported peptides under mild conditions.
• Demonstration of versatile side-chain substitutions and side-chain-to-side-chain cyclizations.
• Enabling selective [13C] acyl labeling of modified peptides.
• The reaction was efficiently performed in a single vial.

Conclusions:

• The reported method offers a mild and efficient strategy for N-capping peptides in SPPS.
• This approach provides versatility for creating diverse peptide structures and labeled peptides.
• The single-vial reaction simplifies the process and enhances its applicability.