Photoredox-mediated metal-free ring-opening metathesis polymerization (MF-ROMP) is a convenient metal-free method to produce a variety of ROMP polymers. Transitioning MF-ROMP from a batch to a continuous flow process has yet to be demonstrated and could potentially benefit the production efficiency, safety, and modularity of reaction conditions. We designed and evaluated continuous flow and droplet flow setups and compared the results for MF-ROMP across a short series of common monomers. By using the droplet flow reactor setup, we achieved flow conversions comparable to that of batch and circumvented issues with diffusion-limited mixing and air exposure.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acsmacrolett.3c00545 | DOI Listing |
ACS Macro Lett
November 2023
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
Photoredox-mediated metal-free ring-opening metathesis polymerization (MF-ROMP) is a convenient metal-free method to produce a variety of ROMP polymers. Transitioning MF-ROMP from a batch to a continuous flow process has yet to be demonstrated and could potentially benefit the production efficiency, safety, and modularity of reaction conditions. We designed and evaluated continuous flow and droplet flow setups and compared the results for MF-ROMP across a short series of common monomers.
View Article and Find Full Text PDFOrg Lett
May 2023
Institute of Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40255 Düsseldorf, Germany.
An efficient metal-free, photoredox-mediated cascade cyclization of aryl 1-haloalk-5-ynyl ketones has been developed. Using catalytic amounts of eosin Y (EY) and EtNMe as a reductive quencher, various aryl 1-haloalk-5-ynyl ketones have been transformed into the corresponding cyclization products in up to 98% yield. As a result, synthetic access to differently α-functionalized cyclopenta[]naphthones and direct construction of cyclopenta[]naphtholes has been developed.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2023
Department of Macromolecular Science, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China.
Organocatalyzed reversible-deactivation radical polymerizations (RDRPs) are attractive for many applications. Here, we developed photoredox-mediated RDRP by activating (hetero)aryl sulfonyl chloride (ArSO Cl) initiators with pyridines and designing a novel bis(phenothiazine)arene catalyst. The in situ formed sulfonyl pyridinium intermediates effectively promote controlled chain-growth from ArSO Cl, enabling access to various well-defined polymers with high initiation efficiencies and controlled dispersities under mild conditions.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2021
Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Stereochemistry can have a profound impact on polymer and materials properties. Unfortunately, straightforward methods for realizing high levels of stereocontrolled polymerizations are often challenging to achieve. In a departure from traditional metal-mediated ring-opening metathesis polymerization (ROMP), we discovered a remarkably simple method for controlling alkene stereochemistry in photoredox mediated metal-free ROMP.
View Article and Find Full Text PDFAcc Chem Res
October 2020
Department of Chemistry, University of Washington, Seattle, Washington 98115, United States.
Ring-opening metathesis polymerization (ROMP), which is derived from transition-metal-based olefin metathesis, has evolved into one of the most prevalent technologies for making functional polymeric materials in academia and in industry. The initial discovery of and advances in ROMP used ill-defined mixtures of metal salts to initiate polymerization. The initiators most commonly used today, developed with tremendous efforts, are well-defined metal-alkylidene complexes that have enabled a good mechanistic understanding of the polymerization as well as improvement of the initiators' activity, stability, and functional group tolerance.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!