Modular synthesis of aryl amines from 3-alkynyl-2-pyrones.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• 3-alkynyl-2-pyrones are versatile precursors in organic synthesis.
• Aryl amines are crucial building blocks in pharmaceuticals and materials science.

Purpose of the Study:

• To describe a novel synthetic route for aryl amines from 3-alkynyl-2-pyrones and secondary amines.
• To elucidate the reaction mechanism and identify key factors influencing efficiency.

Main Methods:

• Reaction of 3-alkynyl-2-pyrones with various secondary amines.
• Mechanistic investigation involving selective opening, decarboxylation, and rearrangement.
• Support from quantum chemical transition-state calculations.
• Data-driven modeling and scope exploration to assess reaction efficiency.

Main Results:

• Successful synthesis of aryl amines from diverse 3-alkynyl-2-pyrones and secondary amines.
• Proposed mechanism involving 1,6-selective opening, decarboxylation, and rearrangement.
• Quantum chemical calculations support the proposed regiochemical outcome.
• Reaction efficiency is significantly influenced by the steric bulk of the secondary amine.

Conclusions:

• A new, efficient method for aryl amine synthesis has been developed.
• The steric properties of secondary amines are critical for optimizing this transformation.
• The findings provide valuable insights for designing future synthetic strategies.