Tetrathienoanthracene-functionalized conjugated microporous polymers as an efficient, metal-free visible-light solid organocatalyst for heterogeneous photocatalysis

Abstract

Owning to their advantages of superior inherent porosity, high chemical stability, light-weight, and molecularly tunable optoelectronic properties, conjugated microporous polymers (CMPs) have been received increasing attention and research interest as...

Metal–organic framework (MOF)-, covalent-organic framework (COF)-, and porous-organic polymers (POP)-catalyzed selective C–H bond activation and functionalization reactions

“…111 Regarding CMPs, Han and coworkers carried out the synthesis of TTA-CMP, which contains tetrathienoanthracene units, through Sonogashira-Hagihara coupling. 175 Besides CDC reactions, they carried out the light-mediated synthesis of benzimidazoles from 1,2-diaminobenzene and different aromatic aldehydes. In this case, the reaction starts with imine condensation, which can easily undergo a single-electron transfer process from the excited state of the photocatalyst (Fig.…”

“…164 In addition, pristine POPs can be designed through the assembly of building blocks that already present some intrinsic catalytic activity in their molecular forms. Based on this principle, organic dyes such as Rose Bengal, 169 Eosine Y, 170 carbazoles, 174 phenyl phenothiazine 379 and tetrathienoanthracene, 175 among others, have been incorporated into different types of POPs, which have been used for different C–H activation and C–H functionalization reactions. The use of pristine organic materials can be considered the most employed strategy to prepare POPs with interesting photocatalytic activities, which can be applied to synthetic organic chemistry.…”

Porous organic polymers for light-driven organic transformations

“…7c). 109 The obtained TTA-CMPs featured a wide visible absorption range (band edge E 800 nm), a suitable optical bandgap (E g = 2.08 eV) and a sufficiently negative conduction band potential (E c = À1.20 V). These excellent photoelectric properties are also well reflected in two classical coupling reactions (CDC and the dehydrogenative-Mannich reaction) and a cyclo-condensation reaction (synthesis of benzimidazoles).…”

“…7b), 108 and Wang (Fig. 7c) 109 have coincidentally chosen sulfur-containing monomers to construct CMPs. From the structures, it can be seen that thiophene units are the core of these S-containing monomers, and their electron-rich properties and good light-trapping ability are the main reasons for their enhanced photocatalytic activity.…”

“…Wang's group also selected a sulfur-rich, planar, extended π-system structural unit, tetrathienoanthracene, to construct CMPs. 109 They found that TTA-CMP can mediate the photocatalytic synthesis of benzimidazoles with high yields. They also proposed a very reasonable catalytic process based on their mechanistic investigation experiments.…”