A Covalent Triazine Framework for Photocatalytic Anti-Markovnikov Hydrofunctionalizations

Area of Science:

• Materials Science
• Organic Chemistry
• Photocatalysis

Background:

• Heterogeneous photocatalysts based on porous materials enhance organic transformations.
• Covalent triazine frameworks (CTFs) offer tunable properties for catalysis.
• Efficient mass and charge transfer are crucial for photocatalytic efficiency.

Purpose of the Study:

• To develop a novel porous crystalline covalent triazine framework (CTF)-based heterogeneous photocatalyst.
• To investigate its photoredox properties for various hydrofunctionalization reactions.
• To understand the mechanism underlying its catalytic activity.

Main Methods:

• Synthesis and characterization of a porous crystalline CTF.
• Application of the CTF as a photocatalyst for hydrocarboxylations, hydroamination, and hydroazidations.
• Mechanistic studies involving characterization and investigation of property changes upon protonation.

Main Results:

• The CTF exhibited excellent photoredox properties for hydrocarboxylations, hydroamination, and hydroazidations.
• Activation of styrenes and regioselective C-N and C-O bond formation were achieved at ambient conditions.
• The photocatalytic activity was linked to changes in the CTF's physicochemical and optoelectronic properties upon protonation.
• The approach was successfully extended to the late-stage functionalization of bioactive molecules.

Conclusions:

• A CTF-based heterogeneous photocatalyst enables efficient and selective hydrofunctionalization reactions.
• Protonation-induced property changes in the CTF are key to its photocatalytic mechanism.
• This catalytic system offers broad substrate scope and applicability in late-stage functionalization.