Iodine-Mediated Multicomponent Deaminative Cyclization for Direct Transformation of Inert Amides into Aromatic...

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Heterocyclic Chemistry

Background:

• Amide bonds are resonance-stabilized, making the C-N bond difficult to cleave and posing challenges for functionalization.
• Traditional methods for amide functionalization often yield linear esters, limiting the synthesis of complex structures.

Purpose of the Study:

• To develop a novel multicomponent strategy for direct amide functionalization.
• To enable the selective activation, deamination, and cyclization of amides in a one-pot process.
• To synthesize structurally unique aromatic heterocyclic scaffolds, specifically α-pyrone aromatic lactones.

Main Methods:

• A multicomponent [3+2+1] deaminative cyclization strategy was employed.
• The reaction utilized readily available aryl ethyl ketones, 4-hydroxy-1-methylquinolin-2(1H)-one, and active methylene amides.
• The cyclization was performed under iodine (I2)/dimethyl sulfoxide (DMSO) conditions.

Main Results:

• The protocol achieved selective amide activation, deamination, and cyclization in a single pot.
• Structurally unique α-pyrone aromatic lactones were efficiently assembled.
• This method overcomes limitations of traditional ester formation, enabling direct amide-to-lactone transformation.

Conclusions:

• This work establishes a new platform for the functionalization of inert amide bonds.
• The developed protocol provides a powerful tool for the synthesis of complex aromatic heterocycles.
• The strategy offers a direct route to aromatic lactones from amides within a multicomponent framework.