Investigation of sol–gel supported palladium catalysts for Heck coupling reactions in o/w-microemulsions

Volovych, I.; Kasaka, Yasemin; Schwarze, Michael; Nairoukh, Zackaria; Blum, Jochanan; Fanun, Monzer; Avnir, David; Schomäcker, Reinhard

doi:10.1016/j.molcata.2014.06.016

Cited by 15 publications

(19 citation statements)

References 42 publications

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“…1 consists of three steps: (a) Suzuki coupling, (b) hydrogenation (reduction of the nitro group in the coupling product), and (c) condensation to the nal product. Heck coupling of iodobenzene and styrene catalysed by sol-gel immobilized palladium catalysts 17 and Suzuki coupling catalysed by carbon supported palladium. To prevent waste in tandem reactions, the amounts of solvent have to be minimised (reduced E-factor), e.g.…”

Section: Introductionmentioning

confidence: 99%

A novel process concept for the three step Boscalid® synthesis

et al. 2016

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Nowadays, the development of chemical processes using environmentally friendly solvents is of high importance. As an alternative to conventional reaction media based on organic solvents, we show a novel aqueous surfactant-based process concept which is used for the three step synthesis of the fungicide Boscalid®. By applying three phase microemulsion systems for the Suzuki coupling reaction, the first step within the Boscalid® synthesis, a simple product and catalyst separation can be achieved, whereby the water-soluble homogeneous Pd/SPhos catalyst complex can be reused several times.Together with an easily recyclable heterogeneous PtIr@TiO 2 catalyst, which is applied for the hydrogenation reaction in the second step, followed by base-assisted condensation to the final product Boscalid® in the third step, overall yields up to 90% are achievable for the whole reaction sequence. This result was obtained without any purification step in between that requires the use of further solvents. In this way the total synthesis costs can be reduced and solvent wastage can be avoided.

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Section: Introductionmentioning

confidence: 99%

A novel process concept for the three step Boscalid® synthesis

et al. 2016

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“…A concentration of 0.5 mol L −1 correlates with a nearly 3‐fold CMC of OMIM and a 55‐fold CMC of DodecMIM. By using DodecMIM, more surfactant molecules are available for micelle formation, higher solubilization is reached, resulting in higher conversion and yields 9, 13, 19.…”

Section: Resultsmentioning

confidence: 99%

“…This leads to higher solubilization within the micelles and higher reaction rates. At a constant surfactant concentration of 0.5 mol L -1 , the catalyst activity increases with the increasing length of the alkyl chain molecules are available for micelle formation, higher solubilization is reached, resulting in higher conversion and yields [9,13,19].…”

Section: Determination Of Palladium and Phosphorous Leachingmentioning

confidence: 99%

Ionic Liquids as Surfactants in Aqueous Multiphase Systems for the Pd‐Catalyzed Hydrocarboxylation

Weber

Isbrücker

Schmidt

et al. 2020

Chemie Ingenieur Technik

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This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Dedicated to Prof. Dr.-Ing. Matthias Kraume on the occasion of his 65th birthday The suitability of ionic liquids (alkylmethylimidazolium bromides) as surfactants in an aqueous multiphase system for the Pd-catalyzed hydrocarboxylation of 1-dodecene is discussed. Attention is paid to the influence of these ionic liquids on the reaction performance and the phase separation. All tested ionic liquids are suitable as surfactants, but their concentration has a strong impact on the reaction performance. The resulting product concentrations are crucial for the phase behavior and so for the phase separation. In recycling experiments, the Pd-catalyst is successfully separated and reused.

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“…by micellar enhanced ultra filtration (MEUF) or adsorption on silica or granite sand. 39 The application of heterogeneous catalysts is very advantageous because of easy separation and high stability of the immobilized particles, whereas entrapment of active material during the synthesis and mass transport limitations during the reaction can lead to decreased activities.…”

Section: Reactions With Heterogeneous Micro-and Mesoporous Silica Sup...mentioning

confidence: 99%