[{"volume":11,"user_id":"94","_id":"59510","publisher":"MDPI AG","status":"public","citation":{"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.” <i>Gels</i>, vol. 11, no. 4, 278, MDPI AG, 2025, doi:<a href=\"https://doi.org/10.3390/gels11040278\">10.3390/gels11040278</a>.","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. <i>Gels</i>. 2025;11(4). doi:<a href=\"https://doi.org/10.3390/gels11040278\">10.3390/gels11040278</a>","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={<a href=\"https://doi.org/10.3390/gels11040278\">10.3390/gels11040278</a>}, number={4278}, journal={Gels}, publisher={MDPI AG}, author={Killi, Naresh and Rumpke, Katja and Kuckling, Dirk}, year={2025} }","apa":"Killi, N., Rumpke, K., &#38; Kuckling, D. (2025). Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst. <i>Gels</i>, <i>11</i>(4), Article 278. <a href=\"https://doi.org/10.3390/gels11040278\">https://doi.org/10.3390/gels11040278</a>","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,” <i>Gels</i>, vol. 11, no. 4, Art. no. 278, 2025, doi: <a href=\"https://doi.org/10.3390/gels11040278\">10.3390/gels11040278</a>.","short":"N. Killi, K. Rumpke, D. Kuckling, Gels 11 (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.” <i>Gels</i> 11, no. 4 (2025). <a href=\"https://doi.org/10.3390/gels11040278\">https://doi.org/10.3390/gels11040278</a>."},"doi":"10.3390/gels11040278","language":[{"iso":"eng"}],"main_file_link":[{"url":"https://www.mdpi.com/2310-2861/11/4/278"}],"article_number":"278","intvolume":"        11","date_updated":"2025-04-11T07:13:26Z","publication_status":"published","publication_identifier":{"issn":["2310-2861"]},"author":[{"last_name":"Killi","first_name":"Naresh","full_name":"Killi, Naresh"},{"full_name":"Rumpke, Katja","last_name":"Rumpke","first_name":"Katja"},{"id":"287","full_name":"Kuckling, Dirk","last_name":"Kuckling","first_name":"Dirk"}],"title":"Synthesis of Curcumin Derivatives via Knoevenagel Reaction Within a Continuously Driven Microfluidic Reactor Using Polymeric Networks Containing Piperidine as a Catalyst","year":"2025","department":[{"_id":"163"}],"keyword":["flow chemistry","heterogeneous catalysis","sustainable synthesis","organo-catalysis","polymeric gel dots"],"type":"journal_article","date_created":"2025-04-11T07:12:02Z","abstract":[{"lang":"eng","text":"<jats:p>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.</jats:p>"}],"issue":"4","publication":"Gels"},{"date_updated":"2024-04-03T11:07:31Z","publication_status":"published","intvolume":"         9","article_type":"original","title":"Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors","year":"2023","author":[{"full_name":"Killi, Naresh","last_name":"Killi","first_name":"Naresh"},{"full_name":"Bartenbach, Julian","first_name":"Julian","last_name":"Bartenbach"},{"id":"287","last_name":"Kuckling","first_name":"Dirk","full_name":"Kuckling, Dirk"}],"publication_identifier":{"issn":["2310-2861"]},"doi":"10.3390/gels9030171","article_number":"171","language":[{"iso":"eng"}],"abstract":[{"text":"<jats:p>The Knoevenagel reaction is a classic reaction in organic chemistry for the formation of C-C bonds. In this study, various catalytic monomers for Knoevenagel reactions were synthesized and polymerized via photolithography to form polymeric gel dots with a composition of 90% catalyst, 9% gelling agent and 1% crosslinker. Furthermore, these gel dots were inserted into a microfluidic reactor (MFR) and the conversion of the reaction using gel dots as catalysts in the MFR for 8 h at room temperature was studied. The gel dots containing primary amines showed a better conversion of about 83–90% with aliphatic aldehyde and 86–100% with aromatic aldehyde, compared to the tertiary amines (52–59% with aliphatic aldehyde and 77–93% with aromatic aldehydes) which resembles the reactivity of the amines. Moreover, the addition of polar solvent (water) in the reaction mixture and the swelling properties of the gel dots by altering the polymer backbone showed a significant enhancement in the conversion of the reaction, due to the increased accessibility of the catalytic sites in the polymeric network. These results suggested the primary-amine-based catalysts facilitate better conversion compared to tertiary amines and the reaction solvent had a significant influence on organocatalysis to improve the efficiency of MFR.</jats:p>","lang":"eng"}],"issue":"3","publication":"Gels","type":"journal_article","keyword":["Knoevenagel reaction","organocatalysis","polymeric gel dots","microfluidic reactions","polymeric networks"],"department":[{"_id":"163"}],"date_created":"2024-04-03T11:06:26Z","status":"public","user_id":"94","volume":9,"_id":"53166","publisher":"MDPI AG","citation":{"ieee":"N. Killi, J. Bartenbach, and D. Kuckling, “Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors,” <i>Gels</i>, vol. 9, no. 3, Art. no. 171, 2023, doi: <a href=\"https://doi.org/10.3390/gels9030171\">10.3390/gels9030171</a>.","apa":"Killi, N., Bartenbach, J., &#38; Kuckling, D. (2023). Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors. <i>Gels</i>, <i>9</i>(3), Article 171. <a href=\"https://doi.org/10.3390/gels9030171\">https://doi.org/10.3390/gels9030171</a>","chicago":"Killi, Naresh, Julian Bartenbach, and Dirk Kuckling. “Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors.” <i>Gels</i> 9, no. 3 (2023). <a href=\"https://doi.org/10.3390/gels9030171\">https://doi.org/10.3390/gels9030171</a>.","short":"N. Killi, J. Bartenbach, D. Kuckling, Gels 9 (2023).","mla":"Killi, Naresh, et al. “Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors.” <i>Gels</i>, vol. 9, no. 3, 171, MDPI AG, 2023, doi:<a href=\"https://doi.org/10.3390/gels9030171\">10.3390/gels9030171</a>.","bibtex":"@article{Killi_Bartenbach_Kuckling_2023, title={Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors}, volume={9}, DOI={<a href=\"https://doi.org/10.3390/gels9030171\">10.3390/gels9030171</a>}, number={3171}, journal={Gels}, publisher={MDPI AG}, author={Killi, Naresh and Bartenbach, Julian and Kuckling, Dirk}, year={2023} }","ama":"Killi N, Bartenbach J, Kuckling D. Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel Reaction within Continuously Driven Microfluidic Reactors. <i>Gels</i>. 2023;9(3). doi:<a href=\"https://doi.org/10.3390/gels9030171\">10.3390/gels9030171</a>"}},{"date_created":"2019-04-29T13:07:39Z","department":[{"_id":"151"}],"keyword":["biomedical measurement","brain","cancer","neurophysiology","phantoms","phase locked loops","piezoelectric actuators","surgery","tactile sensors","transfer functions","tumours","PLL","biomedical tissue differentiation system","brain tumor resection","frequency control","frequency shift","gel-phantom","high sensitivity actuator-sensor system","neurosurgery","phase-locked loop","piezoelectric actuators","piezoelectric bimorph","self-oscillating circuit","sensor sensitivity","tactile differentiation","tactile sensor system","transfer function","tumor boundary","visual differentiation","Biomedical measurements","Circuits","Frequency control","Neoplasms","Neurosurgery","Phase locked loops","Piezoelectric actuators","Surges","Transfer functions","Voltage"],"type":"conference","citation":{"mla":"Uribe, David Oliva, et al. “Development of a Biomedical Tissue Differentiation System Using Piezoelectric Actuators.” <i>Frequency Control Symposium, 2008 IEEE International</i>, 2008, pp. 91–94, doi:<a href=\"https://doi.org/10.1109/FREQ.2008.4622963\">10.1109/FREQ.2008.4622963</a>.","bibtex":"@inproceedings{Uribe_Stroop_Hemsel_Wallaschek_2008, title={Development of a biomedical tissue differentiation system using piezoelectric actuators}, DOI={<a href=\"https://doi.org/10.1109/FREQ.2008.4622963\">10.1109/FREQ.2008.4622963</a>}, booktitle={Frequency Control Symposium, 2008 IEEE International}, author={Uribe, David Oliva and Stroop, Ralf and Hemsel, Tobias and Wallaschek, Jörg}, year={2008}, pages={91–94} }","ama":"Uribe DO, Stroop R, Hemsel T, Wallaschek J. Development of a biomedical tissue differentiation system using piezoelectric actuators. In: <i>Frequency Control Symposium, 2008 IEEE International</i>. ; 2008:91-94. doi:<a href=\"https://doi.org/10.1109/FREQ.2008.4622963\">10.1109/FREQ.2008.4622963</a>","ieee":"D. O. Uribe, R. Stroop, T. Hemsel, and J. Wallaschek, “Development of a biomedical tissue differentiation system using piezoelectric actuators,” in <i>Frequency Control Symposium, 2008 IEEE International</i>, 2008, pp. 91–94.","apa":"Uribe, D. O., Stroop, R., Hemsel, T., &#38; Wallaschek, J. (2008). Development of a biomedical tissue differentiation system using piezoelectric actuators. In <i>Frequency Control Symposium, 2008 IEEE International</i> (pp. 91–94). <a href=\"https://doi.org/10.1109/FREQ.2008.4622963\">https://doi.org/10.1109/FREQ.2008.4622963</a>","short":"D.O. Uribe, R. Stroop, T. Hemsel, J. Wallaschek, in: Frequency Control Symposium, 2008 IEEE International, 2008, pp. 91–94.","chicago":"Uribe, David Oliva, Ralf Stroop, Tobias Hemsel, and Jörg Wallaschek. “Development of a Biomedical Tissue Differentiation System Using Piezoelectric Actuators.” In <i>Frequency Control Symposium, 2008 IEEE International</i>, 91–94, 2008. <a href=\"https://doi.org/10.1109/FREQ.2008.4622963\">https://doi.org/10.1109/FREQ.2008.4622963</a>."},"publication":"Frequency Control Symposium, 2008 IEEE International","abstract":[{"text":"In neurosurgery, delineation of tumor boundaries during resection of brain tumors is of substantial relevance. During operation distinction between tumor and healthy tissue rely on the abilities of the surgeon based on visual and tactile differentiation. In this paper a high sensitivity actuator-sensor system using a piezoelectric bimorph is presented. Frequency shift and transfer function of the bimorphpsilas voltages are detected and evaluated. Sensorpsilas sensitivity is evaluated using two frequency controls strategies: A phase-locked loop (PLL) and a self-oscillating circuit. Results of measurements conducted on gel-phantoms are presented and discussed.","lang":"eng"}],"quality_controlled":"1","language":[{"iso":"eng"}],"_id":"9576","page":"91-94","user_id":"55222","doi":"10.1109/FREQ.2008.4622963","publication_identifier":{"issn":["1075-6787"]},"author":[{"first_name":"David Oliva","last_name":"Uribe","full_name":"Uribe, David Oliva"},{"full_name":"Stroop, Ralf","last_name":"Stroop","first_name":"Ralf"},{"first_name":"Tobias","last_name":"Hemsel","full_name":"Hemsel, Tobias","id":"210"},{"full_name":"Wallaschek, Jörg","first_name":"Jörg","last_name":"Wallaschek"}],"status":"public","title":"Development of a biomedical tissue differentiation system using piezoelectric actuators","year":"2008","date_updated":"2022-01-06T07:04:16Z"}]