Total Synthesis of Feglymycin Using Umpolung Amide Synthesis.

Area of Science:

• Organic Chemistry
• Medicinal Chemistry
• Chemical Biology

Background:

• Peptide synthesis is crucial for advancing chemical biology, catalysis, and drug discovery.
• Conventional amide synthesis methods have limitations, including restricted chemical space access and stereochemical inaccuracies.
• Current methods, especially in solid-phase peptide synthesis, often rely on hazardous reagents and excess coupling agents, which is unsustainable.

Purpose of the Study:

• To develop a more sustainable and efficient method for peptide synthesis.
• To replace conventional amide synthesis with umpolung amide synthesis (UmAS) in the preparation of complex peptides.
• To enable the enantioselective synthesis of noncanonical amino acid residues.

Main Methods:

• The study employed umpolung amide synthesis (UmAS) to form half of the amide bonds in the antiviral tridecapeptide feglymycin.
• Enantioselective synthesis of noncanonical residues was achieved starting from inexpensive aldehydes.
• A chiral Brønsted acid organocatalyst and potassium iodide/urea·hydrogen peroxide (KI/UHP) were utilized.

Main Results:

• Successful synthesis of the antiviral tridecapeptide feglymycin using a combination of UmAS and conventional methods.
• UmAS facilitated the enantioselective synthesis of each noncanonical residue.
• The process simplified key synthetic components, utilizing a chiral Brønsted acid organocatalyst and KI/UHP.

Conclusions:

• The total synthesis demonstrates a strategic integration of complementary amide synthesis techniques.
• This approach offers a greener alternative for synthesizing peptides containing noncanonical amino amides.
• The findings provide a benchmark for sustainable peptide synthesis, advancing drug discovery and chemical biology tools.