Migrating Group Strategy for Remote Functionalization of Seven-Membered Rings.

Area of Science:

• Organic Chemistry
• Synthetic Methodology
• Photocatalysis

Background:

• Seven-membered rings are crucial in bioactive molecules but challenging to synthesize.
• Traditional methods often require complex ring assembly or pre-functionalized building blocks.
• Direct functionalization of simpler cyclic precursors is an attractive synthetic alternative.

Purpose of the Study:

• To develop a novel photocatalytic strategy for the synthesis of substituted seven-membered rings.
• To enable direct functionalization of readily available cyclic precursors.
• To address limitations in current synthetic methodologies for medium-sized rings.

Main Methods:

• Photocatalytic transannular ketone migration using sodium decatungstate and thiol cocatalysts.
• Utilizing light-emitting diode (LED) irradiation under mild conditions.
• Employing a dynamic kinetic approach involving reversible hydrogen atom transfer and radical-mediated migration.

Main Results:

• Conversion of 1,1-disubstituted acylcycloheptanes into 1,4-disubstituted products.
• Demonstration of site-selective C-H functionalization within the seven-membered ring.
• Regioselective access to densely substituted seven-membered ring systems.

Conclusions:

• The developed photocatalytic method provides an efficient and regioselective route to substituted seven-membered rings.
• This strategy overcomes challenges associated with traditional synthesis of medium-sized rings.
• The approach offers a valuable new tool for accessing complex molecular architectures in medicinal chemistry and materials science.