EDOT-Decorated Covalent Organic Polymers as Versatile Metal-Free Photocatalysts for Organic Transformations

Covalentorganic polymers (COPs) with conjugated systems and chromophoresare often used as super-organic dyes and have potential in photocatalysis.It is necessary to exploit heterogeneous metal-free photocatalystswith wide applicability and high efficiency. 3,4-Ethylenedioxythiophene(EDOT) here was designed as the photoactive unit and constructed intothe EDOT-conjugated microporous polymer (EDOT-CMP) and EDOT-covalenttriazine framework (EDOT-CTF). The photoelectric properties of thetwo synthetic EDOT-COPs were thus enhanced. Of note is that EDOT-triazineendowed the EDOT-CTF with an obvious donor-acceptor structureand thus generated favorable exciton dissociation efficiency. EDOT-COPsproved to be versatile photocatalysts for photoredox reactions. Atleast eight conversions, e.g., oxidative couplingof benzylamines (85- > 99% yield) and construction of C-Sbondsin olefines (80-96% yield) and indoles (88-99% yield),could be promoted smoothly by EDOT-COPs and especially EDOT-CTFs.EDOT-COPs also showed high photoactivities for the degradation ofrhodamine B. The research about EDOT-COPs here contributes referencesfor the design and synthesis of widely applicable COP photocatalysts.