Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction

Abstract

Poly(quinuclidin-3-yl methacrylate-co-divinylbenzene) microparticles having porous as well as nonporous morphology and varying contents of quinuclidine functionality were synthesized by distillation−precipitation polymerization. Further, the synthesized microparticles were explored to catalyze the Baylis−Hillman reaction between 4-nitrobenzaldehyde and acrylonitrile. Porous and nonporous microparticles functionalized with a catalytic moiety with a loading of 70% (labeled as P 70 and NP 70 ) were employed to optimize reaction parameters such as water content, solvent, and temperature for the Baylis−Hillman reaction between 4-nitrobenzaldehyde and acrylonitrile. Using optimal conditions, the catalytic efficiency of porous and nonporous microparticles at different feed compositions was determined. Porous microparticles containing 70% of quinuclidine (P 70 ) displayed 100% conversion within 16 h at 50 °C, while nonporous microparticles containing 70% of quinuclidine (NP 70 ) displayed a relatively less catalytic conversion, which is attributed to their lower surface area. Furthermore, the catalytic activity of porous microparticles containing 70% of quinuclidine (P 70 ) for the Baylis−Hillman reaction involving a variety of aryl aldehyde derivatives was determined, where the microparticles displayed impressive catalytic efficiency. In addition, the reusability of the microparticles functionalized with a catalytic moiety was evaluated for five cycles of catalytic reaction.

Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors

“…Subsequently, an improved conversion of the reaction and high turnover frequency of the catalyst can be obtained. Similarly, various polymeric networks have been developed in the form of micro or macrogels with the loading of various catalysts to perform several organic reactions, such as the aldol reaction [ 21 ], dimerization, Knoevenagel reaction, Baylis–Hillman reaction, Mannich reaction, etc., in the batch method [ 22 , 23 , 24 ]. Furthermore, packed-bed flow reactors are a type of reactor that uses a dense assembly of a catalytically active polymeric material as a carrier to facilitate chemical reactions.…”

Sustainable Sulfonic Acid Functionalized Tubular Shape Mesoporous Silica as a Heterogeneous Catalyst for Selective Unsymmetrical Friedel–Crafts Alkylation in One Pot

“…Therefore, the development of efficient and environmentally sustainable synthetic strategies is the prime task of organic chemists in chemical science. 16 Thus, in the past decade, tremendous work has been devoted to the consideration of eco-friendly synthetic approaches in both academia and industries using solvent-free techniques, 17 water media, 18 ionic liquids, 19 solid-supported catalysts, 20 phase transfer catalysts, 21 microwave irradiation, 22 or ball-milling processes. 23 In recent years, heterogeneous catalysis or solid-supported catalysts have drawn immense interest in the development of greener synthetic strategies due to their significant merits such as high surface area, easy availability, ordered porous structure, less or no corrosion, high thermal and chemical stability, low cost and persistence in all organic solvents, no waste or disposal problems, and recyclability.…”