---
_id: '59510'
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>
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. <i>Gels</i>. 2025;11(4). doi:<a href="https://doi.org/10.3390/gels11040278">10.3390/gels11040278</a>
  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>
  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} }'
  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>.
  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>.'
  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>.
  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: '53166'
abstract:
- lang: eng
  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>
article_number: '171'
article_type: original
author:
- first_name: Naresh
  full_name: Killi, Naresh
  last_name: Killi
- first_name: Julian
  full_name: Bartenbach, Julian
  last_name: Bartenbach
- first_name: Dirk
  full_name: Kuckling, Dirk
  id: '287'
  last_name: Kuckling
citation:
  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>
  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>
  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} }'
  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>.
  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>.'
  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>.
  short: N. Killi, J. Bartenbach, D. Kuckling, Gels 9 (2023).
date_created: 2024-04-03T11:06:26Z
date_updated: 2024-04-03T11:07:31Z
department:
- _id: '163'
doi: 10.3390/gels9030171
intvolume: '         9'
issue: '3'
keyword:
- Knoevenagel reaction
- organocatalysis
- polymeric gel dots
- microfluidic reactions
- polymeric networks
language:
- iso: eng
publication: Gels
publication_identifier:
  issn:
  - 2310-2861
publication_status: published
publisher: MDPI AG
status: public
title: Polymeric Networks Containing Amine Derivatives as Organocatalysts for Knoevenagel
  Reaction within Continuously Driven Microfluidic Reactors
type: journal_article
user_id: '94'
volume: 9
year: '2023'
...