Light-empowered contra-thermodynamic stereochemical editing.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Photocatalysis

Background:

• Stereochemistry is crucial in organic synthesis, with traditional methods focusing on stereoselectivity-determining steps.
• Stereochemical editing offers a strategy for late-stage modification of molecular stereochemistry, independent of scaffold construction.
• Many stereochemical editing processes are thermodynamically unfavorable (contra-thermodynamic).

Purpose of the Study:

• To review the fundamental mechanisms of visible-light photocatalysis in stereochemical editing.
• To highlight the reactivity modes of photogenerated radical intermediates in contra-thermodynamic transformations.
• To showcase synthetically valuable applications of photocatalytic stereochemical editing.

Main Methods:

• Utilizing visible-light photocatalysis to generate reactive radical species.
• Employing photogenerated radicals to overcome thermodynamic barriers in stereochemical transformations.
• Investigating the mechanisms of radical intermediates in driving these reactions.

Main Results:

• Demonstrated photocatalysis as a powerful tool for contra-thermodynamic stereochemical editing.
• Highlighted key applications including deracemization, alkene isomerization, and epimerization of diols and sugars.
• Provided insights into the general reactivity modes of radical intermediates.

Conclusions:

• Visible-light photocatalysis offers a viable strategy for thermodynamically challenging stereochemical editing.
• This approach enables late-stage control and generation of diverse stereoisomers from single precursors.
• Photocatalytic methods expand the synthetic chemist's toolkit for precise stereochemical manipulation.