Rose Bengal Immobilized on Supported Ionic‐Liquid‐like Phases: An Efficient Photocatalyst for Batch and Flow Processes

Abstract

The catalytic activity of Rose Bengal (RB) immobilized on supported ionic liquid (IL)‐like phases was evaluated as a polymer‐supported photocatalyst. In these systems, the polymer was designed to play a pivotal role. The polymeric backbone adequately modified with IL‐like moieties (supported IL‐like phases, SILLPs) was not just an inert support for the dye but controlled the accessibility of reagents/substrates to the active sites and provided specific microenvironments for the reaction. The structure of SILLPs could be finetuned to adjust the catalytic efficiency of the RB‐SILLP composites, achieving systems that were more active and stable than the related systems in the absence of IL‐like units.

Selective Production of Maleic Acid from Furfural via a Cascade Approach Combining Photochemistry and Electro- or Biochemistry

“…Besides furfural, 2 can also be synthesized starting from furan, 2-furoic acid, or furfuryl alcohol using similar conditions. While starting from 2-furoic acid or furfuryl alcohol results in similar yields, − a lower yield (35%) was reported when starting from furan . Using a custom-made photoreactor setup (see Supporting Information), the photochemical oxidation of 1 was reproduced in good yield and high selectivity (>95%) to 2 .…”

Diverse Supports for Immobilization of Catalysts in Continuous Flow Reactors

“…García‐Verdugo and coworkers [39] modified the polymer backbones with ionic‐liquids (ILs) by polymerization of monomers containing imidazolium fragments and prepared IL‐like polymeric materials (PILs) for the immobilization of Rose Bengal (RB) for continuous flow reactions. The polymeric supports were not inert but controlled the accessibility of reagents/substrates to the active sites and provided specific microenvironments for the reaction.…”

Multifunctional Polymers Based on Ionic Liquid and Rose Bengal Fragments for the Conversion of CO2 to Carbonates

“…6−10 The combination of an organocatalyst with the ionic liquidlike phase of SILLPs was thus considered and Rose Bengal (RB) was initially selected. RB can be easily immobilized onto SILLPs by covalent anchoring (ester formation) or by ionic exchange, just by exposing the corresponding SILLPs to a solution of RB, 27 and Zhang, Zhou, and co-workers have exploited rhodamine B (RhB) and rhodamine 6G (Rh6G) in the presence of a base (Et 3 N) as organocatalytic systems for the cycloaddition of CO 2 with epoxides. 28 RhB and Rh6G are xanthene dyes from the same family of Rose Bengal, which encouraged the study of the cheap and easily prepared polymeric composites RB-SILLPs for this process.…”