Direct Aziridine Synthesis from Amines and Styrene Derivatives via a Base-Promoted Oxidative Cascade Reaction

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Catalysis

Background:

• Aziridines are valuable heterocyclic compounds with broad applications in pharmaceuticals and materials science.
• Existing synthetic methods for aziridines often require harsh conditions or specific oxidants, limiting their scope and applicability.

Purpose of the Study:

• To develop a novel, base-promoted protocol for the direct synthesis of aziridines from readily available primary amines and styrene derivatives.
• To establish a mild and modular synthetic strategy for accessing diverse N-substituted aziridines.

Main Methods:

• A base-promoted cascade reaction involving hydroamination of styrenes, deprotonative benzylic halogenation, and subsequent cyclization.
• Utilizing 2-halothiophenes as selective halogen sources in a Curtin-Hammett oxidative scenario.
• Employing quantum chemical modeling to understand reaction mechanisms and selectivity.

Main Results:

• Successful direct synthesis of aziridines from primary anilines and alkylamines with diverse N-substituents.
• Demonstrated tolerance of the reaction to sensitive functional groups and difficult-to-oxidize substrates.
• Developed a protocol for transforming β-phenethylamines into N-H aziridine derivatives.

Conclusions:

• The developed base-promoted cascade process offers a new, complementary approach to aziridine synthesis.
• The method's mild conditions, modularity, and substrate scope highlight its broad synthetic potential.
• This work showcases the utility of base-promoted halogen transfer in cascade reactions for constructing complex molecules.