Dimethyl Dihydroacridines as Photocatalysts in Organocatalyzed Atom Transfer Radical Polymerization of Acrylate Monomers. Issue 8 (21st January 2020)

• Record Type: Journal Article
• Authors: Buss, Bonnie L.; Lim, Chern‐Hooi; Miyake, Garret M.
• Is Part Of: Angewandte Chemie international edition. Volume 59:Issue 8(2020)
• Page Start: 3209
• Page End: 3217
• Publication Date: 2020-01-21
• Subjects: microreactors -- monomers -- organocatalysis -- photochemistry -- polymerization; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201910828
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Development of photocatalysts (PCs) with diverse properties has been essential in the advancement of organocatalyzed atom transfer radical polymerization (O‐ATRP). Dimethyl dihydroacridines are presented here as a new family of organic PCs, for the first time enabling controlled polymerization of challenging acrylate monomers by O‐ATRP. Structure–property relationships for seven PCs are established, demonstrating tunable photochemical and electrochemical properties, and accessing a strongly oxidizing 2 PC .+ intermediate for efficient deactivation. In O‐ATRP, the combination of PC, implementation of continuous‐flow reactors, and promotion of deactivation through addition of LiBr are critical to producing well‐defined acrylate polymers with dispersities as low as 1.12. The utility of this approach is established through demonstration of the oxygen‐tolerance of the system and application to diverse acrylate monomers, including the synthesis of well‐defined di‐ and triblock copolymers. Abstract : Polymers in flow : Organic photoredox catalysis is applied to the controlled synthesis of poly(acrylates). This advancement is enabled by the development of new organic photoredox catalysts, dimethyl dihydroacridines, with unique properties. The use of continuous flow reactors is also key to the success of the method.