Radical Sampling Enabled Saturated N-Heterocycle Cyclization.

Area of Science:

• Organic Chemistry
• Medicinal Chemistry
• Synthetic Chemistry

Background:

• Nitrogen-containing saturated heterocycles are crucial in drug discovery.
• Current methods for synthesizing these heterocycles are often limited in scope and efficiency.
• A key challenge is the selective activation of C-H bonds in unfunctionalized amines.

Purpose of the Study:

• To develop a general and efficient strategy for synthesizing versatile saturated heterocycles.
• To expand the scope of existing methods by utilizing unfunctionalized amines.
• To overcome the challenge of selective C-H bond activation in heterocycle synthesis.

Main Methods:

• A modular strategy involving in situ condensation of aldehydes and amines.
• Radical generation and cyclization using a radical sampling mechanism.
• Leveraging kinetic differences in competing cyclization pathways for selectivity.

Main Results:

• Successful construction of versatile saturated heterocycles directly from aldehydes and amines.
• Demonstration of a general cyclization strategy applicable to unfunctionalized amines.
• Efficient synthesis of target six-membered rings through selective radical intermediate quenching.

Conclusions:

• The reported radical sampling strategy provides a general and efficient route to valuable nitrogen-containing heterocycles.
• This approach significantly expands the modularity and accessibility of these important scaffolds.
• The method offers a streamlined pathway for drug discovery and development.