Cobalt-Catalyzed Cascade C-H Activation/Annulation Polymerizations toward Diversified and Multifunctional...

Area of Science:

• Polymer Chemistry
• Organic Synthesis
• Materials Science

Background:

• Transition-metal-catalyzed C-H activation is crucial for functional polymer synthesis.
• Constructing multifunctional fused heterocyclic polymers via C-H activation-based polyannulations is challenging.
• Novel polymerization methods are needed for complex polymer architectures.

Purpose of the Study:

• To develop a novel cobalt(III)-catalyzed cascade C-H activation/annulation polymerization (CAAP) approach.
• To synthesize multifunctional sulfur-containing fused heterocyclic (SFH) polymers.
• To explore the properties and potential applications of the synthesized SFH polymers.

Main Methods:

• Employing cobalt(III) catalysis for cascade C-H activation and annulation polymerization.
• Utilizing aryl thioamides and internal diynes as readily available monomers.
• Characterizing the resulting SFH polymers using various analytical techniques.

Main Results:

• Efficient synthesis of SFH polymers with complex, multisubstituted S,N-doped polycyclic units in high yields (up to 99%) and molecular weights (up to 220,400).
• Demonstration of SFH polymers as reactive macromonomers for chain extension and modification.
• Enrichment of structural diversity via S-oxidation and N-methylation reactions.
• Obtained polymers exhibit excellent solution processability, high thermal stability, tunable fluorescence, stimuli-responsiveness, and high refractive indices (up to 1.8464).

Conclusions:

• The Co(III)-catalyzed CAAP provides an efficient route to novel SFH polymers.
• The synthesized SFH polymers possess unique properties suitable for advanced applications.
• Potential applications include metal ion detection, photodynamic therapy, photopatterning, and optical materials.