Two novel polymers of intrinsic microporosity decorated with chiral thioureas have been used as recoverable organocatalysts in enantioselective α-amination of 3-aryl-substituted oxindoles, creating a quaternary stereocenter. Both catalysts were able to promote the reaction in excellent yields and good enantioselection. Catalyst II, with a pyridyl nucleus, was used in recycling experiments maintaining the activity without additional reactivation, and in flow processes allowing the synthesis of the amination product in multigram scale.
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http://dx.doi.org/10.1039/d0ob01373k | DOI Listing |
Angew Chem Int Ed Engl
January 2025
State Key Laboratory of Separation Membranes and Membrane Processes, School of Materials Science and Engineering, Tiangong University, Tianjin, 300387, P. R. China.
The global quest for clean energy and sustainable processes makes advanced membrane extremely attractive for energy-intensive industrial gas separations. Here, we disclosed a series of ultra-high-performance gas separation membranes (PIM-3D-TB) from novel network polymers of intrinsic microporosity (PIM) that combine the advantages of solution processible PIM and small pore size distribution (PSD) of porous organic polymers (POP), which was synthesized by in situ copolymerization of triptycene-2,6-diamine as linear part and triptycene-2,6,13(14)-triamine (TTA) as crosslinker. The resulting PIM-3D-TB membranes demonstrated outstanding separation properties that outperformed the latest trade-off lines for H/CH and O/N.
View Article and Find Full Text PDFAdv Mater
January 2025
Laboratory of Advanced Theranostic Materials and Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, P. R. China.
Ionic conductive hydrogels have emerged as an excellent option for constructing dielectric layers of interfacial iontronic sensors. Among these, gradient ionic hydrogels, due to the intrinsic gradient elastic modulus, can achieve a wide range of pressure responses. However, the fabrication of gradient hydrogels with optimal mechanical and sensing properties remains a challenge.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, P. R. China.
Aerogels are regarded as the next generation of thermal insulators; however, conventional aerogels suffer from issues such as brittleness, low moisture resistance, and a complex production process. Subnanowires (SNWs) are emerging materials known for their exceptional flexibility, toughness, intrinsic hydrophobicity, and gelling capabilities, making them ideal building blocks for flexible, tough, hydrophobic, and thermally insulating aerogels. Herein, we present a simple and scalable strategy to construct SNW aerogels by freeze-drying hydroxyapatite (HAP) SNW dispersions in cyclohexane.
View Article and Find Full Text PDFACS Appl Polym Mater
January 2025
Department of Chemistry, Faculty of Science and Engineering, Swansea University, Grove Building, Singleton Park, Swansea SA2 8PP, U.K.
Heterogeneous catalysis is significantly enhanced by the use of highly porous polymers with specific functionalities, such as basic groups, which accelerate reaction rates. Polymers of intrinsic microporosity (PIMs) provide a unique platform for catalytic reactions owing to their high surface areas and customizable pore structures. We herein report a series of Tröger's base polymers (TB-PIMs) with enhanced basicity, achieved through the incorporation of nitrogen-containing groups into their repeat units, such as triazine and triphenylamine.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, People's Republic of China.
Visible-light-driven photocatalytic uranium extraction based covalent organic frameworks (COFs) are green and sustainable, but their performance is severely restricted by a strong exciton effect. Herein, inspired by the physiology of cardiac pacing, a novel fluorine-based COF (PyF-DaS-COF) with a biomimetic electronic pump has been fabricated and used for the photocatalytic extraction of uranium. Both experimental and theoretical calculations confirm that strongly electronegative fluorine plays a crucial role in exciton dissociation and charge transfer.
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