Organocatalyzed Photoredox Polymerization from Aromatic Sulfonyl Halides: Facilitating Graft from Aromatic C–H Bonds

Abstract

Aromatic sulfonyl halides are readily accessible from many sources. With newly synthesized N-arylphenothiazine catalysts, organocatalyzed photoredox polymerization has been developed with arylsulfonyl halides initiators using white or purple LEDs light sources. This method allows the preparation of poly(meth)acrylates and poly(meth)acrylamides possessing a broad scope of (hetero)aryl chain ends without metal-contamination concern. Investigations such as MALDI-TOF analysis, chain extension, and "ON/ OFF" control experiments confirmed the fidelity of the polymer structure and reliability of this method. Moreover, this method facilitates the two-step preparation of brush polymers from polystyrene through an electrophilic aromatic substitution/ organocatalyzed photopolymerization sequence.

Photoorganocatalyzed Divergent Reversible‐Deactivation Radical Polymerization towards Linear and Branched Fluoropolymers

“…a monomer that can polymerize, and act as a branching site exclusively after incorporated into polymer) [6] . Organic compounds of Eosin Y (PC1) [16] and phenothiazine (PC2) [10c, 17] were selected due to their different potentials at excited states (PC1 and PC2, E ⊖ (PC .+ /PC*)=−1.25 and −1.94 V vs . SCE, Figure 1 A, Figures S1 and S2).…”

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

“…Organophotocatalysis has been exploited to promote this reduction. For example, Chen and co-workers designed the new organic dye OD17 in 2018 (Scheme 43, E(PC •+ /PC*) ≈ −1.9 V), able of reducing the arylsulfonyl chlorides 43.1 (E red = −0.94 V) to initiate the synthesis of the polyacrylates and polyacrylamides 43.3 [173]. To bypass the strong reductive conditions communally used for the activation of sulfamoyl chlorides to form the corresponding sulfamoyl radicals, Gouverneur and co-workers developed an efficient method based on chloride abstractions.…”

“…Illustrative example for the reductive photocatalytic generation of sulfonyl radicals from arylsulfonyl chlorides: the acrylate and acrylamide polymerization reported by Chen and co-workers[173].…”

Emerging Organic Photoredox Catalysts for Organic Transformations

“…The E ox * of 38 was similar to 29 , but only 38 provided well‐controlled semifluorinated (meth)acrylate polymers in the presence of TTC upon visible‐light irradiation due to the low visible‐light absorption of 29 . However, simply improving the absorption profile in the visible‐region of 29 and 39 was insufficient for the preparation of poly(meth)acrylates and poly(meth)acrylamides possessing (hetero)aryl chain ends . The proposed mechanism was similar to that of O‐ATRP except for using an arylsulfonyl halide instead of an alkyl halide as the initiator.…”