--- _id: '59510' abstract: - lang: eng text: The use of organo-catalysis in continuous-flow reactor systems is gaining attention in medicinal chemistry due to its cost-effectiveness and reduced chemical waste. In this study, bioactive curcumin (CUM) derivatives were synthesized in a continuously operated microfluidic reactor (MFR), using piperidine-based polymeric networks as catalysts. Piperidine methacrylate and piperidine acrylate were synthesized and subsequently copolymerized with complementary monomers (MMA or DMAA) and crosslinkers (EGDMA or MBAM) via photopolymerization, yielding different polymeric networks. Initially, batch reactions were optimized for the organo-catalytic Knoevenagel condensation between CUM and 4-nitrobenzaldehyde, under various conditions, in the presence of polymer networks. Conversion was assessed using offline 1H NMR spectroscopy, revealing an increase in conversion with enhanced swelling properties of the polymer networks, which facilitated greater accessibility of catalytic sites. In continuous-flow MFR experiments, optimized polymer gel dots exhibited superior catalytic performance, achieving a conversion of up to 72%, compared to other compositions. This improvement was attributed to the enhanced swelling in the reaction mixture (DMSO/methanol, 7:3 v/v) at 40 °C over 72 h. Furthermore, the MFR system enabled the efficient synthesis of a series of CUM derivatives, demonstrating significantly higher conversion rates than traditional batch reactions. Notably, while batch reactions required 90% catalyst loading in the gel, the MFR system achieved a comparable or superior performance with only 50% catalyst, resulting in a higher turnover number. These findings underscore the advantages of continuous-flow organo-catalysis in enhancing catalytic efficiency and sustainability in organic synthesis. article_number: '278' author: - first_name: Naresh full_name: Killi, Naresh last_name: Killi - first_name: Katja full_name: Rumpke, Katja last_name: Rumpke - first_name: Dirk full_name: Kuckling, Dirk id: '287' last_name: Kuckling citation: ama: Killi N, Rumpke K, Kuckling D. Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst. Gels. 2025;11(4). doi:10.3390/gels11040278 apa: Killi, N., Rumpke, K., & Kuckling, D. (2025). Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst. Gels, 11(4), Article 278. https://doi.org/10.3390/gels11040278 bibtex: '@article{Killi_Rumpke_Kuckling_2025, title={Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst}, volume={11}, DOI={10.3390/gels11040278}, number={4278}, journal={Gels}, publisher={MDPI AG}, author={Killi, Naresh and Rumpke, Katja and Kuckling, Dirk}, year={2025} }' chicago: Killi, Naresh, Katja Rumpke, and Dirk Kuckling. “Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst.” Gels 11, no. 4 (2025). https://doi.org/10.3390/gels11040278. ieee: 'N. Killi, K. Rumpke, and D. Kuckling, “Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst,” Gels, vol. 11, no. 4, Art. no. 278, 2025, doi: 10.3390/gels11040278.' mla: Killi, Naresh, et al. “Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst.” Gels, vol. 11, no. 4, 278, MDPI AG, 2025, doi:10.3390/gels11040278. short: N. Killi, K. Rumpke, D. Kuckling, Gels 11 (2025). date_created: 2025-04-11T07:12:02Z date_updated: 2025-04-11T07:13:26Z department: - _id: '163' doi: 10.3390/gels11040278 intvolume: ' 11' issue: '4' keyword: - flow chemistry - heterogeneous catalysis - sustainable synthesis - organo-catalysis - polymeric gel dots language: - iso: eng main_file_link: - url: https://www.mdpi.com/2310-2861/11/4/278 publication: Gels publication_identifier: issn: - 2310-2861 publication_status: published publisher: MDPI AG status: public title: Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst type: journal_article user_id: '94' volume: 11 year: '2025' ... --- _id: '63970' abstract: - lang: eng text: Abstract Recent advances in solid-state nuclear magnetic resonance (NMR) spectroscopy, combined with dynamic nuclear polarization (DNP), quantum chemical DFT calculations, and gas-phase NMR spectroscopy investigating the structure and reactivity of heterogeneous catalysts are reviewed. The investigated catalysts range from classical mononuclear catalysts, like immobilized derivates of Wilkinson’s catalysts over binuclear catalysts such as the dirhodium paddlewheel catalyst to catalytic nanoparticles, employing various support materials, such as mesoporous silica gels, coordination polymers, and biomaterials such as cellulose. author: - first_name: Nadia full_name: Haro Mares, Nadia last_name: Haro Mares - first_name: Millena full_name: Logrado, Millena last_name: Logrado - first_name: Jan full_name: Kergassner, Jan last_name: Kergassner - first_name: Bingyu full_name: Zhang, Bingyu last_name: Zhang - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: Haro Mares N, Logrado M, Kergassner J, Zhang B, Gutmann T, Buntkowsky G. Solid-State NMR of Heterogeneous Catalysts. ChemCatChem. Published online 2024:e202401159. doi:10.1002/cctc.202401159 apa: Haro Mares, N., Logrado, M., Kergassner, J., Zhang, B., Gutmann, T., & Buntkowsky, G. (2024). Solid-State NMR of Heterogeneous Catalysts. ChemCatChem, e202401159. https://doi.org/10.1002/cctc.202401159 bibtex: '@article{Haro Mares_Logrado_Kergassner_Zhang_Gutmann_Buntkowsky_2024, title={Solid-State NMR of Heterogeneous Catalysts}, DOI={10.1002/cctc.202401159}, journal={ChemCatChem}, publisher={John Wiley & Sons, Ltd}, author={Haro Mares, Nadia and Logrado, Millena and Kergassner, Jan and Zhang, Bingyu and Gutmann, Torsten and Buntkowsky, Gerd}, year={2024}, pages={e202401159} }' chicago: Haro Mares, Nadia, Millena Logrado, Jan Kergassner, Bingyu Zhang, Torsten Gutmann, and Gerd Buntkowsky. “Solid-State NMR of Heterogeneous Catalysts.” ChemCatChem, 2024, e202401159. https://doi.org/10.1002/cctc.202401159. ieee: 'N. Haro Mares, M. Logrado, J. Kergassner, B. Zhang, T. Gutmann, and G. Buntkowsky, “Solid-State NMR of Heterogeneous Catalysts,” ChemCatChem, p. e202401159, 2024, doi: 10.1002/cctc.202401159.' mla: Haro Mares, Nadia, et al. “Solid-State NMR of Heterogeneous Catalysts.” ChemCatChem, John Wiley & Sons, Ltd, 2024, p. e202401159, doi:10.1002/cctc.202401159. short: N. Haro Mares, M. Logrado, J. Kergassner, B. Zhang, T. Gutmann, G. Buntkowsky, ChemCatChem (2024) e202401159. date_created: 2026-02-07T15:40:38Z date_updated: 2026-02-17T16:17:30Z doi: 10.1002/cctc.202401159 extern: '1' keyword: - solid-state nmr - heterogeneous catalysis - dynamic nuclear polarization - Nanocatalysis - Surface-reactions language: - iso: eng page: e202401159 publication: ChemCatChem publication_identifier: issn: - 1867-3880 publisher: John Wiley & Sons, Ltd status: public title: Solid-State NMR of Heterogeneous Catalysts type: journal_article user_id: '100715' year: '2024' ... --- _id: '35645' abstract: - lang: eng text: 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 P70 and NP70) 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 (P70) displayed 100% conversion within 16 h at 50 °C, while nonporous microparticles containing 70% of quinuclidine (NP70) 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 (P70) 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. article_type: original author: - first_name: Amit full_name: Kumar, Amit last_name: Kumar - first_name: Dirk full_name: Kuckling, Dirk id: '287' last_name: Kuckling - first_name: Leena full_name: Nebhani, Leena last_name: Nebhani citation: ama: Kumar A, Kuckling D, Nebhani L. Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction. ACS Applied Polymer Materials. 2022;4(12):8996-9005. doi:10.1021/acsapm.2c01330 apa: Kumar, A., Kuckling, D., & Nebhani, L. (2022). Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction. ACS Applied Polymer Materials, 4(12), 8996–9005. https://doi.org/10.1021/acsapm.2c01330 bibtex: '@article{Kumar_Kuckling_Nebhani_2022, title={Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction}, volume={4}, DOI={10.1021/acsapm.2c01330}, number={12}, journal={ACS Applied Polymer Materials}, publisher={American Chemical Society (ACS)}, author={Kumar, Amit and Kuckling, Dirk and Nebhani, Leena}, year={2022}, pages={8996–9005} }' chicago: 'Kumar, Amit, Dirk Kuckling, and Leena Nebhani. “Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction.” ACS Applied Polymer Materials 4, no. 12 (2022): 8996–9005. https://doi.org/10.1021/acsapm.2c01330.' ieee: 'A. Kumar, D. Kuckling, and L. Nebhani, “Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction,” ACS Applied Polymer Materials, vol. 4, no. 12, pp. 8996–9005, 2022, doi: 10.1021/acsapm.2c01330.' mla: Kumar, Amit, et al. “Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction.” ACS Applied Polymer Materials, vol. 4, no. 12, American Chemical Society (ACS), 2022, pp. 8996–9005, doi:10.1021/acsapm.2c01330. short: A. Kumar, D. Kuckling, L. Nebhani, ACS Applied Polymer Materials 4 (2022) 8996–9005. date_created: 2023-01-10T08:07:12Z date_updated: 2023-01-10T08:12:15Z department: - _id: '163' doi: 10.1021/acsapm.2c01330 intvolume: ' 4' issue: '12' keyword: - distillation−precipitation polymerization - porous microparticles - heterogeneous catalysis Baylis−Hillman reaction - reusable catalyst language: - iso: eng main_file_link: - url: https://pubs.acs.org/doi/10.1021/acsapm.2c01330 page: 8996-9005 publication: ACS Applied Polymer Materials publication_identifier: issn: - 2637-6105 - 2637-6105 publication_status: published publisher: American Chemical Society (ACS) status: public title: Quinuclidine-Immobilized Porous Polymeric Microparticles as a Compelling Catalyst for the Baylis–Hillman Reaction type: journal_article user_id: '94' volume: 4 year: '2022' ... --- _id: '63960' abstract: - lang: eng text: Recent advances in solid-state nuclear magnetic resonance (NMR) spectroscopy and dynamic nuclear polarization (DNP) of nanostructured materials are reviewed. A first group of materials is based on crystalline nanocellulose (CNC) or microcrystalline cellulose (MCC), which are used as carrier materials for dye molecules, catalysts or in combination with heterocyclic molecules as ion conducting membranes. These materials have widespread applications in sensorics, optics, catalysis or fuel cell research. A second group are metal oxides such as V-Mo-W oxides, which are of enormous importance in the manufacturing process of basic chemicals. The third group are catalytically active nanocrystalline metal nanoparticles, coated with protectants or embedded in polymers. The last group includes of lead-free perovskite materials, which are employed as environmentally benign substitution materials for conventional lead-based electronics materials. These materials are discussed in terms of their application and physico-chemical characterization by solid-state NMR techniques, combined with gas-phase NMR and quantum-chemical modelling on the density functional theory (DFT) level. The application of multinuclear 1H, 2H, 13C, 15N and 23Na solid state NMR techniques under static or MAS conditions for the characterization of these materials, their surfaces and processes on their surfaces is discussed. Moreover, the analytic power of the combination of these techniques with DNP for the identification of low-concentrated carbon and nitrogen containing surface species in natural abundance is reviewed. Finally, approaches for sensitivity enhancement by DNP of quadrupolar nuclei such as 17O and 51V are presented that enable the identification of catalytic sites in metal oxide catalysts. author: - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Pedro B. full_name: Groszewicz, Pedro B. last_name: Groszewicz - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: Gutmann T, Groszewicz PB, Buntkowsky G. Solid-state NMR of nanocrystals. Annual Reports on NMR Spectroscopy. 2019;97:1–82. doi:10.1016/bs.arnmr.2018.12.001 apa: Gutmann, T., Groszewicz, P. B., & Buntkowsky, G. (2019). Solid-state NMR of nanocrystals. Annual Reports on NMR Spectroscopy, 97, 1–82. https://doi.org/10.1016/bs.arnmr.2018.12.001 bibtex: '@article{Gutmann_Groszewicz_Buntkowsky_2019, title={Solid-state NMR of nanocrystals}, volume={97}, DOI={10.1016/bs.arnmr.2018.12.001}, journal={Annual Reports on NMR Spectroscopy}, author={Gutmann, Torsten and Groszewicz, Pedro B. and Buntkowsky, Gerd}, year={2019}, pages={1–82} }' chicago: 'Gutmann, Torsten, Pedro B. Groszewicz, and Gerd Buntkowsky. “Solid-State NMR of Nanocrystals.” Annual Reports on NMR Spectroscopy 97 (2019): 1–82. https://doi.org/10.1016/bs.arnmr.2018.12.001.' ieee: 'T. Gutmann, P. B. Groszewicz, and G. Buntkowsky, “Solid-state NMR of nanocrystals,” Annual Reports on NMR Spectroscopy, vol. 97, pp. 1–82, 2019, doi: 10.1016/bs.arnmr.2018.12.001.' mla: Gutmann, Torsten, et al. “Solid-State NMR of Nanocrystals.” Annual Reports on NMR Spectroscopy, vol. 97, 2019, pp. 1–82, doi:10.1016/bs.arnmr.2018.12.001. short: T. Gutmann, P.B. Groszewicz, G. Buntkowsky, Annual Reports on NMR Spectroscopy 97 (2019) 1–82. date_created: 2026-02-07T15:37:03Z date_updated: 2026-02-17T16:17:56Z doi: 10.1016/bs.arnmr.2018.12.001 extern: '1' intvolume: ' 97' keyword: - solid-state nmr - heterogeneous catalysis - dynamic nuclear polarization - Ferroelectrics - Nanocatalysis - Surface reactions language: - iso: eng page: 1–82 publication: Annual Reports on NMR Spectroscopy status: public title: Solid-state NMR of nanocrystals type: journal_article user_id: '100715' volume: 97 year: '2019' ... --- _id: '63956' abstract: - lang: eng text: The synthesis of novel robust and stable iridium-based immobilized catalysts on silica-polymer hybrid materials (Si-PB-Ir) is described. These catalysts are characterized by a combination of 1D P-31 CP-MAS and 2D P-31-H-1 HETCOR and J-resolved multinuclear solid state NMR experiments. Different binding situations such as singly and multiply coordinated phosphines are identified. Density functional theory (DFT) calculations are performed to corroborate the interpretation of the experimental NMR data, in order to propose a structural model of the heterogenized catalysts. Finally, the catalytic activity of the Si-PB-Ir catalysts is investigated for the hydrogenation of styrene employing para-enriched hydrogen gas. author: - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: S. full_name: Alkhagani, S. last_name: Alkhagani - first_name: N. full_name: Rothermel, N. last_name: Rothermel - first_name: H. H. full_name: Limbach, H. H. last_name: Limbach - first_name: H. full_name: Breitzke, H. last_name: Breitzke - first_name: G. full_name: Buntkowsky, G. last_name: Buntkowsky citation: ama: Gutmann T, Alkhagani S, Rothermel N, Limbach HH, Breitzke H, Buntkowsky G. P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts. Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics. 2017;231(3):653–669. doi:10.1515/zpch-2016-0837 apa: Gutmann, T., Alkhagani, S., Rothermel, N., Limbach, H. H., Breitzke, H., & Buntkowsky, G. (2017). P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts. Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics, 231(3), 653–669. https://doi.org/10.1515/zpch-2016-0837 bibtex: '@article{Gutmann_Alkhagani_Rothermel_Limbach_Breitzke_Buntkowsky_2017, title={P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts}, volume={231}, DOI={10.1515/zpch-2016-0837}, number={3}, journal={Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics}, author={Gutmann, Torsten and Alkhagani, S. and Rothermel, N. and Limbach, H. H. and Breitzke, H. and Buntkowsky, G.}, year={2017}, pages={653–669} }' chicago: 'Gutmann, Torsten, S. Alkhagani, N. Rothermel, H. H. Limbach, H. Breitzke, and G. Buntkowsky. “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel Heterogenized Iridium-Catalysts.” Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics 231, no. 3 (2017): 653–669. https://doi.org/10.1515/zpch-2016-0837.' ieee: 'T. Gutmann, S. Alkhagani, N. Rothermel, H. H. Limbach, H. Breitzke, and G. Buntkowsky, “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts,” Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics, vol. 231, no. 3, pp. 653–669, 2017, doi: 10.1515/zpch-2016-0837.' mla: Gutmann, Torsten, et al. “P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel Heterogenized Iridium-Catalysts.” Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics, vol. 231, no. 3, 2017, pp. 653–669, doi:10.1515/zpch-2016-0837. short: T. Gutmann, S. Alkhagani, N. Rothermel, H.H. Limbach, H. Breitzke, G. Buntkowsky, Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics 231 (2017) 653–669. date_created: 2026-02-07T15:35:41Z date_updated: 2026-02-17T16:18:04Z doi: 10.1515/zpch-2016-0837 extern: '1' intvolume: ' 231' issue: '3' keyword: - Chemistry - dynamic nuclear-polarization - solid-state nmr - DFT - heterogeneous catalysis - hydrido complexes - hydrogenation - immobilized catalyst - inorganic hybrid - iridium - materials - mesoporous - molecular-orbital methods - PHIP - phosphine complexes - reusable catalysts - silica - solid-state-NMR - wilkinsons catalyst language: - iso: eng page: 653–669 publication: Zeitschrift Fur Physikalische Chemie-International Journal of Research in Physical Chemistry & Chemical Physics publication_identifier: issn: - 0942-9352 status: public title: P-31-Solid-State NMR Characterization and Catalytic Hydrogenation Tests of Novel heterogenized Iridium-Catalysts type: journal_article user_id: '100715' volume: 231 year: '2017' ... --- _id: '64047' abstract: - lang: eng text: A novel strategy for the immobilization of Wilkinson’s catalyst on silica nanoparticles is presented, employing pyridyl linkers as anchoring groups. The coordination binding of the catalyst to the pyridyl linker via ligand exchange of the trans-phosphine group is verified by 1 D and 2 D solid-state NMR spectroscopy. Catalytic activities are monitored by GC employing the hydrogenation of styrene as model reaction, and the leaching properties as well as the robustness of the catalyst are investigated. The resulting immobilized catalyst shows high catalytic activity, which is within a factor of three comparable to the homogeneous catalyst, and excellent stability in leaching tests. Finally, it is efficient to produce hyperpolarization in solution by employing parahydrogen-enriched hydrogen gas for hydrogenation. author: - first_name: Mohamad full_name: Srour, Mohamad last_name: Srour - first_name: Sara full_name: Hadjiali, Sara last_name: Hadjiali - first_name: Grit full_name: Sauer, Grit last_name: Sauer - first_name: Kai full_name: Brunnengräber, Kai last_name: Brunnengräber - first_name: Hergen full_name: Breitzke, Hergen last_name: Breitzke - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Heiko full_name: Weidler, Heiko last_name: Weidler - first_name: Hans-Heinrich full_name: Limbach, Hans-Heinrich last_name: Limbach - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: Srour M, Hadjiali S, Sauer G, et al. Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance. ChemCatChem. 2016;8(21):3409–3416. doi:10.1002/cctc.201600882 apa: Srour, M., Hadjiali, S., Sauer, G., Brunnengräber, K., Breitzke, H., Xu, Y., Weidler, H., Limbach, H.-H., Gutmann, T., & Buntkowsky, G. (2016). Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance. ChemCatChem, 8(21), 3409–3416. https://doi.org/10.1002/cctc.201600882 bibtex: '@article{Srour_Hadjiali_Sauer_Brunnengräber_Breitzke_Xu_Weidler_Limbach_Gutmann_Buntkowsky_2016, title={Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance}, volume={8}, DOI={10.1002/cctc.201600882}, number={21}, journal={ChemCatChem}, author={Srour, Mohamad and Hadjiali, Sara and Sauer, Grit and Brunnengräber, Kai and Breitzke, Hergen and Xu, Yeping and Weidler, Heiko and Limbach, Hans-Heinrich and Gutmann, Torsten and Buntkowsky, Gerd}, year={2016}, pages={3409–3416} }' chicago: 'Srour, Mohamad, Sara Hadjiali, Grit Sauer, Kai Brunnengräber, Hergen Breitzke, Yeping Xu, Heiko Weidler, Hans-Heinrich Limbach, Torsten Gutmann, and Gerd Buntkowsky. “Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance.” ChemCatChem 8, no. 21 (2016): 3409–3416. https://doi.org/10.1002/cctc.201600882.' ieee: 'M. Srour et al., “Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance,” ChemCatChem, vol. 8, no. 21, pp. 3409–3416, 2016, doi: 10.1002/cctc.201600882.' mla: Srour, Mohamad, et al. “Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance.” ChemCatChem, vol. 8, no. 21, 2016, pp. 3409–3416, doi:10.1002/cctc.201600882. short: M. Srour, S. Hadjiali, G. Sauer, K. Brunnengräber, H. Breitzke, Y. Xu, H. Weidler, H.-H. Limbach, T. Gutmann, G. Buntkowsky, ChemCatChem 8 (2016) 3409–3416. date_created: 2026-02-07T16:12:46Z date_updated: 2026-02-17T16:13:06Z doi: 10.1002/cctc.201600882 extern: '1' intvolume: ' 8' issue: '21' keyword: - heterogeneous catalysis - hydrogenation - immobilization - phosphane ligands - rhodium language: - iso: eng page: 3409–3416 publication: ChemCatChem status: public title: Synthesis and Solid-State NMR Characterization of a Robust, Pyridyl-Based Immobilized Wilkinson’s Type Catalyst with High Catalytic Performance type: journal_article user_id: '100715' volume: 8 year: '2016' ... --- _id: '63963' abstract: - lang: eng text: A novel heterogeneous dirhodium catalyst has been synthesized. This stable catalyst is constructed from dirhodium acetate dimer (Rh2(OAc)4) units, which are covalently linked to amine- and carboxyl-bifunctionalized mesoporous silica (SBA-15NH2COOH). It shows good efficiency in catalyzing the cyclopropanation reaction of styrene and ethyl diazoacetate (EDA) forming cis- and trans-1-ethoxycarbonyl-2-phenylcyclopropane. To characterize the structure of this catalyst and to confirm the successful immobilization, heteronuclear solid-state NMR experiments have been performed. The high application potential of dynamic nuclear polarization (DNP) NMR for the analysis of binding sites in this novel catalyst is demonstrated. Signal-enhanced 13C CP MAS and 15N CP MAS techniques have been employed to detect different carboxyl and amine binding sites in natural abundance on a fast time scale. The interpretation of the experimental chemical shift values for different binding sites has been corroborated by quantum chemical calculations on dirhodium model complexes. author: - first_name: Torsten full_name: Gutmann, Torsten id: '118165' last_name: Gutmann - first_name: Jiquan full_name: Liu, Jiquan last_name: Liu - first_name: Niels full_name: Rothermel, Niels last_name: Rothermel - first_name: Yeping full_name: Xu, Yeping last_name: Xu - first_name: Eva full_name: Jaumann, Eva last_name: Jaumann - first_name: Mayke full_name: Werner, Mayke last_name: Werner - first_name: Hergen full_name: Breitzke, Hergen last_name: Breitzke - first_name: Snorri T. full_name: Sigurdsson, Snorri T. last_name: Sigurdsson - first_name: Gerd full_name: Buntkowsky, Gerd last_name: Buntkowsky citation: ama: 'Gutmann T, Liu J, Rothermel N, et al. Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst. Chemistry A European Journal. 2015;21(9):3798–3805. doi:10.1002/chem.201405043' apa: 'Gutmann, T., Liu, J., Rothermel, N., Xu, Y., Jaumann, E., Werner, M., Breitzke, H., Sigurdsson, S. T., & Buntkowsky, G. (2015). Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst. Chemistry A European Journal, 21(9), 3798–3805. https://doi.org/10.1002/chem.201405043' bibtex: '@article{Gutmann_Liu_Rothermel_Xu_Jaumann_Werner_Breitzke_Sigurdsson_Buntkowsky_2015, title={Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst}, volume={21}, DOI={10.1002/chem.201405043}, number={9}, journal={Chemistry A European Journal}, publisher={WILEY-VCH Verlag}, author={Gutmann, Torsten and Liu, Jiquan and Rothermel, Niels and Xu, Yeping and Jaumann, Eva and Werner, Mayke and Breitzke, Hergen and Sigurdsson, Snorri T. and Buntkowsky, Gerd}, year={2015}, pages={3798–3805} }' chicago: 'Gutmann, Torsten, Jiquan Liu, Niels Rothermel, Yeping Xu, Eva Jaumann, Mayke Werner, Hergen Breitzke, Snorri T. Sigurdsson, and Gerd Buntkowsky. “Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst.” Chemistry A European Journal 21, no. 9 (2015): 3798–3805. https://doi.org/10.1002/chem.201405043.' ieee: 'T. Gutmann et al., “Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst,” Chemistry A European Journal, vol. 21, no. 9, pp. 3798–3805, 2015, doi: 10.1002/chem.201405043.' mla: 'Gutmann, Torsten, et al. “Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst.” Chemistry A European Journal, vol. 21, no. 9, WILEY-VCH Verlag, 2015, pp. 3798–3805, doi:10.1002/chem.201405043.' short: T. Gutmann, J. Liu, N. Rothermel, Y. Xu, E. Jaumann, M. Werner, H. Breitzke, S.T. Sigurdsson, G. Buntkowsky, Chemistry A European Journal 21 (2015) 3798–3805. date_created: 2026-02-07T15:38:07Z date_updated: 2026-02-17T16:17:50Z doi: 10.1002/chem.201405043 extern: '1' intvolume: ' 21' issue: '9' keyword: - heterogeneous catalysis - immobilized catalyst - dynamic nuclear polarization - hyperpolarization - NMR spectroscopy language: - iso: eng page: 3798–3805 publication: Chemistry A European Journal publisher: WILEY-VCH Verlag status: public title: 'Natural Abundance 15N NMR by Dynamic Nuclear Polarization: Fast Analysis of Binding Sites of a Novel Amine-Carboxyl-Linked Immobilized Dirhodium Catalyst' type: journal_article user_id: '100715' volume: 21 year: '2015' ...