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Search for "flow reactor" in Full Text gives 110 result(s) in Beilstein Journal of Organic Chemistry.

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

  • Emine Kayahan,
  • Mathias Jacobs,
  • Leen Braeken,
  • Leen C.J. Thomassen,
  • Simon Kuhn,
  • Tom van Gerven and
  • M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

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Published 08 Oct 2020

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

  • Shahboz Yakubov and
  • Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

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  • through small-diameter (μm–mm) channels. Lectka and co-workers reported the processing of their benzil-photosensitized enone-directed C(sp3)–H fluorination in a custom-built flow reactor, comprised of a syringe pump, a coil of fluorinated ethylene propylene (FEP) tubing (7.5 m; inner diameter 1.6 mm
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Published 03 Sep 2020

Heterogeneous photocatalysis in flow chemical reactors

  • Christopher G. Thomson,
  • Ai-Lan Lee and
  • Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

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  • the molar attenuation coefficient of the photocatalyst (ε), its concentration (c), and the optical path length (l). This also applies to immobilising an HPCat in a flow reactor, which generally confines and concentrates the material within a transparent vessel with high surface-to-volume ratio
  • conjugated polymer and applied the material for singlet oxygen photosensitisation [131]. Both of these were applied as HPCats in a commercial flow reactor for photocatalysis. Whilst flow chemistry is generally used to enhance the efficiency of HPC processes, we recently demonstrated that it can also enhance
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Published 26 Jun 2020

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

  • Mateo Berton,
  • Kevin Sheehan,
  • Andrea Adamo and
  • D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

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  • fresh organomagnesium reagents on a discovery scale and will do so independent from the operator’s experience in flow and/or organometallic chemistry. Keywords: Knochel–Hauser base; lithium chloride; magnesium; on-demand; packed-bed reactors; plug and flow reactor; synthesizer; turbo Grignard reagent
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Published 19 Jun 2020

A method to determine the correct photocatalyst concentration for photooxidation reactions conducted in continuous flow reactors

  • Clemens R. Horn and
  • Sylvain Gremetz

Beilstein J. Org. Chem. 2020, 16, 871–879, doi:10.3762/bjoc.16.78

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  • centered on the combination of light with continuous flow reactors [1][2][3][4][5][6]. The reason for this increased interest is that continuous flow photochemical reactors can overcome various limitations that occur when the same reaction run in batch reactors [7]. For example, the flow reactor can
  • , which, for a flow reactor, is the product of the light intensity and time [27][28][29]. The light intensity can be considered as the limiting factor in a flow setup as the space around the reaction channel is limited, as is the power of the light source. The exposure time has less limitations as it is
  • reagent uses the Bouguer–Lambert–Beer law as a starting point to estimate a concentration close to the optimum. The law in its basic definition is not entirely applicable to a flow reactor but will nevertheless provide a convenient starting point [30][31]. The analysis of the required concentration of the
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Published 27 Apr 2020

Recent advances in photocatalyzed reactions using well-defined copper(I) complexes

  • Mingbing Zhong,
  • Xavier Pannecoucke,
  • Philippe Jubault and
  • Thomas Poisson

Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42

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  • and propylene oxide as a proton scavenger under flow conditions (0.05 mL/min; residence time = 20 h). The use of flow conditions drastically enhanced the kinetics of the reaction, moving from 120 h reaction time in batch to 20 h using a continuous flow reactor. The reaction allowed the synthesis of a
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Published 23 Mar 2020

Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid

  • Kaj M. van Vliet,
  • Nicole S. van Leeuwen,
  • Albert M. Brouwer and
  • Bas de Bruin

Beilstein J. Org. Chem. 2020, 16, 398–408, doi:10.3762/bjoc.16.38

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  • shell. We anticipated that in a flow setup using tubing with a small internal diameter (0.71 mm) the photocatalyzed reaction pathways could be more efficient. However, in this case, performing the reaction under flow conditions did not lead to better results. The reaction performed in a flow reactor led
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Published 16 Mar 2020

Safe and highly efficient adaptation of potentially explosive azide chemistry involved in the synthesis of Tamiflu using continuous-flow technology

  • Cloudius R. Sagandira and
  • Paul Watts

Beilstein J. Org. Chem. 2019, 15, 2577–2589, doi:10.3762/bjoc.15.251

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  • reaction was quenched within the flow reactor using aqueous HCl (0.11 M, 1.1 equiv) when necessary. Samples were collected and analysed using HPLC resulting in 4.84 min retention time for azide 5. For characterisation, an appropriate amount of toluene and water was added to the reaction mixture after
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Published 30 Oct 2019

Tuning the stability of alkoxyisopropyl protection groups

  • Zehong Liang,
  • Henna Koivikko,
  • Mikko Oivanen and
  • Petri Heinonen

Beilstein J. Org. Chem. 2019, 15, 746–751, doi:10.3762/bjoc.15.70

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  • ., 8a (Figure 2). Recently, the same kind of enol ether formation was considered in connection to an optimization of the conditions for MIP protection on secondary and benzylic hydroxy groups of mandelonitrile derivatives in a flow reactor process [9]. All of the studied acetals are stable toward basic
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Published 21 Mar 2019

Low-budget 3D-printed equipment for continuous flow reactions

  • Jochen M. Neumaier,
  • Amiera Madani,
  • Thomas Klein and
  • Thomas Ziegler

Beilstein J. Org. Chem. 2019, 15, 558–566, doi:10.3762/bjoc.15.50

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  • in flow chemistry. We developed a rack of four syringe pumps controlled by one Arduino computer, which can be manufactured with a commonly available 3D printer and readily available parts. Also, we printed various flow reactor cells, which are fully customizable for each individual reaction. With
  • systems is the low chemical resistance of the used printing materials towards most organic solvents [11]. For the development and construction of our flow reactor we had to print and design numerous devices in order to find the most suitable parameters. All reactors were printed with a filament flow of
  • performed under batch conditions according to the literature [38] (Scheme 3). The following conversion of glucose 4 into trichloroacetimidate 5 was done in a flow reactor type R1 with a reaction time of 3.5 min. This way, a yield of 67% was obtained for this glycosylation step. Once again we found that
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Published 26 Feb 2019

Assessing the possibilities of designing a unified multistep continuous flow synthesis platform

  • Mrityunjay K. Sharma,
  • Roopashri B. Acharya,
  • Chinmay A. Shukla and
  • Amol A. Kulkarni

Beilstein J. Org. Chem. 2018, 14, 1917–1936, doi:10.3762/bjoc.14.166

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  • a flow reactor tube of required length and diameter or a microchannel reactor having various geometries or a static mixer) or a continuous stirred tank reactor or a fixed bed reactor or other intensified process equipment viz. spinning disc reactor, impinging jet reactor etc.) and a thermostat which
  • , multiple temperature zones can also be provided if required. The reactor module also includes mixers (M1–M9) that are commonly used in flow chemistry [64][65]. The continuous flow reactor can also be equipped with in-line static mixing elements [63]. The second module includes the intermediate storage
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Published 26 Jul 2018

Mild and selective reduction of aldehydes utilising sodium dithionite under flow conditions

  • Nicole C. Neyt and
  • Darren L. Riley

Beilstein J. Org. Chem. 2018, 14, 1529–1536, doi:10.3762/bjoc.14.129

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  • %, respectively. Flow-based reduction of aldehydes and ketones In developing a flow protocol a Uniqsis FlowSyn Stainless Steel Flow reactor with a Multi X automated sampler was utilized. The reactor set-up (Figure 1) involved the use of two HPLC pumps, a 2 mL mixing chip connected in series to a 14 mL HT PTFE
  • process can be run continuously with minimal loss in reactor productivity. Uniqsis FlowSyn Stainless Steel Flow reactor. Flow reactor configuration for the reduction of aldehydes and ketones. NMR spectra showing the optimisation of the dithionite reduction for the reduction of benzaldehyde. Selective
  • reduction of an aldehyde in the presence of a ketone. Flow reactor set-up for the continuous reduction of aldehydes. Sodium dithionite-mediated reductions under basic conditions. Reduction of aldehydes and ketones under batch and flow conditions. Optimization of the reduction of benzaldehyde under flow
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Published 22 Jun 2018

Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting

  • Jonas Weidner,
  • Stefan Barwe,
  • Kirill Sliozberg,
  • Stefan Piontek,
  • Justus Masa,
  • Ulf-Peter Apfel and
  • Wolfgang Schuhmann

Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121

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  • of the various cobalt–metalloid alloys supported on Ni RDE electrodes revealed CoB to be the most efficient HMF oxidation catalyst. Using a CoB modified Ni foam as anode material, and Ni foam as the cathode in a continuous flow reactor with an anion exchange membrane separating the anodic and
  • of the activities of all investigated CoX-based catalysts (X = B, Si, P, As and Te) is highlighted in Table 1. HMF oxidation in a continuous flow reactor The surprisingly high HMF oxidation activity of CoB made it especially interesting to further study the product distribution and FDCA yield in a
  • continuous mode. For this, a flow reactor was employed which contains two nickel foam (NF) electrodes separated by an anion exchange membrane (Supporting Information File 1, Figure S2). The NF anode (1 cm × 1 cm) was modified with CoB by means of spray coating while pure NF was used as cathode material. The
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Published 13 Jun 2018

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

  • Veronika Hladíková,
  • Jiří Váňa and
  • Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

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  • solid-supported CuSAC reaction in batch or flow reactor.
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Published 05 Jun 2018

Biocatalytic synthesis of the Green Note trans-2-hexenal in a continuous-flow microreactor

  • Morten M. C. H. van Schie,
  • Tiago Pedroso de Almeida,
  • Gabriele Laudadio,
  • Florian Tieves,
  • Elena Fernández-Fueyo,
  • Timothy Noël,
  • Isabel W. C. E. Arends and
  • Frank Hollmann

Beilstein J. Org. Chem. 2018, 14, 697–703, doi:10.3762/bjoc.14.58

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  • overcome by conducting the reaction in a flow-reactor setup reaching unpreceded catalytic activities for the enzyme in terms of turnover frequency (up to 38 s−1) and turnover numbers (more than 300000) pointing towards preparative usefulness of the proposed reaction scheme. Keywords: alcohol oxidase
  • reactor enzymatic oxidation Next, we performed the PeAAOx-catalysed oxidation of trans-hex-2-enol in a slug-flow reactor setup (Supporting Information File 1, Figure S1 and Figures S9–S11). In a first set of experiments we systematically varied the residence time of the reaction mixture in the flow
  • decreasing the flow rates and using a longer flow reactor (6 mL volume instead of 3 mL). Pleasingly, already in these first experiments a TN for the enzyme of more than 300000 was observed at long residence times. This also underlines the robustness of the enzyme under the flow conditions. Compared to Figure
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Published 26 Mar 2018

High-yielding continuous-flow synthesis of antimalarial drug hydroxychloroquine

  • Eric Yu,
  • Hari P. R. Mangunuru,
  • Nakul S. Telang,
  • Caleb J. Kong,
  • Jenson Verghese,
  • Stanley E. Gilliland III,
  • Saeed Ahmad,
  • Raymond N. Dominey and
  • B. Frank Gupton

Beilstein J. Org. Chem. 2018, 14, 583–592, doi:10.3762/bjoc.14.45

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  • resonance of residual CHCl3 (or 0 ppm of TMS) for proton spectra and the 77.23 ppm resonance of CDCl3 for carbon spectra were used as internal references. Continuous-flow experiments were carried out using the E-series flow reactor instrument purchased from Vapourtec Ltd. PFA tubing (1/16 OD × 1 mm ID) was
  • ); 13C NMR (125 MHz, CDCl3) δ 207.4, 44.0, 30.3, 27.2, 6.7. Spectra were obtained in accordance with those previously reported [3]. Synthesis of 5-(ethyl(2-hydroxyethyl)amino)pentan-2-one (6) Telescope of compound 6: Prior to the start of the experiment, the flow reactor unit was rinsed with dry THF and
  • previously reported [38][39]. Synthesis of (E)-5-(ethyl(2-hydroxyethyl)amino)pentan-2-one oxime (11) Flow: Prior to the start of the experiment, the flow reactor unit was rinsed with dry THF and flushed with nitrogen gas. At room temperature, the stock solutions of 5-iodopentan-2-one (10, 1.0 M) and 2
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Published 08 Mar 2018

Continuous multistep synthesis of 2-(azidomethyl)oxazoles

  • Thaís A. Rossa,
  • Nícolas S. Suveges,
  • Marcus M. Sá,
  • David Cantillo and
  • C. Oliver Kappe

Beilstein J. Org. Chem. 2018, 14, 506–514, doi:10.3762/bjoc.14.36

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  • reactors for each step were setup, the reaction conditions re-optimized when necessary, and finally all the steps integrated in a single continuous stream. The thermolysis of vinyl azide 1 was performed in a continuous flow reactor consisting of a perfluoroalkoxy (PFA) coil (0.5 mL, 0.8 mm i.d.) immersed
  • phase. Decomposition of 2-(bromomethyl)oxazoles 6 was successfully avoided by further integrating into the continuous-flow reactor the final nucleophilic halide displacement step with NaN3. The resulting 2-(azidomethyl)oxazole derivatives 7 presented higher stability and could be isolated without
  • to give the desired product. After optimization of all individual steps in batch and continuous-flow mode, the complete sequence has been integrated in a single continuous-flow reactor, in which the vinyl azide is fed as substrate and the final 2-(azidomethyl)oxazole is formed and collected from the
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Published 23 Feb 2018

Latest development in the synthesis of ursodeoxycholic acid (UDCA): a critical review

  • Fabio Tonin and
  • Isabel W. C. E. Arends

Beilstein J. Org. Chem. 2018, 14, 470–483, doi:10.3762/bjoc.14.33

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  • production of UDCA. Different chemical, chemoenzymatic and enzymatic routes will be considered. In addition, the precursors availability as well as the substrate loading in the process and the requisites for potential new routes will be discussed. Furthermore, the potential benefits of a flow reactor setup
  • dehydroxylation reactions are highlighted with a red, blue and green arrow, respectively. Names of compounds are indicated in the box. The general stereoinformation of steroid scaffold is shown in Figure 2. R = 4-pentanoic acid. Schematic representation of the flow reactor for the continuous conversion of CDCA to
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Published 20 Feb 2018

Continuous-flow retro-Diels–Alder reaction: an efficient method for the preparation of pyrimidinone derivatives

  • Imane Nekkaa,
  • Márta Palkó,
  • István M. Mándity and
  • Ferenc Fülöp

Beilstein J. Org. Chem. 2018, 14, 318–324, doi:10.3762/bjoc.14.20

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  • were selected on the basis of the solubility of the starting materials. A schematic representation of the flow reactor setup is illustrated in Figure 1. Products 9–14 thus prepared were identified by means of HPLC–MS and NMR spectroscopic analysis. All physical and spectroscopic data of pyrimidinones 9
  • our system. Surprisingly, however, we could detect traces of di-endo-3-phenyl-4a,5,8,8a-tetrahydro-5,8-ethanoquinazolin-4(3H)-one (15b), resulting from desulfurisation of 8b (Scheme 2). This observation prompted us to investigate whether desulfurisation can occur under the flow reactor conditions. In
  • requiring harsh conditions in batch methods. A simple, efficient and scalable production was implemented with a short processing time, which might open up new horizons for a potential CF industrial synthesis of heterocycles. Schematic outline of the continuous-flow reactor. Flow synthesis for the
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Published 01 Feb 2018

CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na

  • Hélène Guyon,
  • Hélène Chachignon and
  • Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

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  • trifluoromethylation with CF3SO2Na are highly efficient, the original Langlois’ conditions were nevertheless applied to a series of heteroarenes. Li and co-workers reported the synthesis of 3-trifluoromethylcoumarins 64 by Cu(I)-catalysed trifluoromethylation with CF3SO2Na and t-BuOOH in a continuous-flow reactor [61
  • ]. After optimisation of the reaction conditions in batch, the optimal reaction conditions were established in a continuous-flow reactor at a flow rate of 100 µL min−1 at 60 °C for 40 min. The substrate scope was evaluated on 11 coumarins and showed that both electron-rich and electron-deficient functional
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Published 19 Dec 2017

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

  • Marcus Baumann,
  • Ian R. Baxendale and
  • Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

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  • ). EtOAc was promising and made extraction very easy but during the reactions small quantities of a dark red, sticky, precipitate were observed (Table 1, entry 12). This was considered problematic for processing in a meso flow reactor due to the potential for causing blockages. It was however found that
  • cyclisation products 12 and 14, assigned structure of byproduct 15. Synthetic strategy towards desired indole product 8. Initial flow reactor setup for the synthesis of intermediate 11. Coflore ACR setup for the synthesis of intermediate 11. Quenching and work-up of the reaction stream from the Coflore ACR
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Published 29 Nov 2017

Grip on complexity in chemical reaction networks

  • Albert S. Y. Wong and
  • Wilhelm T. S. Huck

Beilstein J. Org. Chem. 2017, 13, 1486–1497, doi:10.3762/bjoc.13.147

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  • network motif based on autocatalytic production and delayed inhibition of an enzyme that was kept out-of-equilibrium. (d) Schematic representation of the flow reactor that is used to implement flow. (e) The output of the reactor was measured using an enzymatic activity in an offline analysis. The response
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Published 28 Jul 2017

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

  • Chinmay A. Shukla and
  • Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

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  • micromixer followed by a flow reactor (usually depicted in the form of a helical coil or a packed column), which is maintained at a desired temperature or a given temperature profile. The outlet stream of the reactor is subsequently mixed with the new reagent and allowed to react for further transformation
  • temperature profiles inside the reactor. Whenever it is not possible to insert temperature sensors along the flow reactor/microreactor due to its compact dimensions (although miniaturized sensors are available almost everywhere), the temperature should be monitored at the inlet (preferably at mixing points
  • and also to avoid undesired side reactions possibly due to prolonged contact of the reactants. The mixed stream has to be followed by a flow reactor with a jacket, where the jacket side fluid can be the manipulating variable whereas the outlet concentration of the reactor can be set as a control
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Published 19 May 2017

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

  • Carmen Moreno-Marrodan,
  • Francesca Liguori and
  • Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

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  • the hydrogenation of 3, the ex-situ particles were deposited onto a ZnO/Sintered Metal Fibers support, having selected this material for its excellent mass transfer properties. The catalyst was then integrated into a bubble column flow reactor with staged catalytic layers, showing two order magnitude
  • from a diffusion-controlled to kinetic-limited regime [163][181]. The non-accumulation of co-products adsorbed on the catalyst surface may also significantly contribute to the minimization of active site inhibition under the conditions of continuous flow [27]. Flow reactor design. Performance
  • differences among different continuous-flow reactor designs are difficult to rationalize due to the number of additional variables related to the catalyst involved, which include: - the role played by the supported metal, e.g., type, loading, MNP size, shape and location [182][183]), - the role played by the
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Published 20 Apr 2017

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

  • Flavio Fanelli,
  • Giovanna Parisi,
  • Leonardo Degennaro and
  • Renzo Luisi

Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51

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  • Ar–Csp3, Ar–Csp2 and Ar–Csp bond-forming reactions. The use of a photochemical flow reactor, consisting of a polyfluorinated tube reactor wrapped around a 500 W Hg lamp, allowed to overcome batch limitations paving the way for metal-free arylation reactions via phenyl cations. Derivatives 14a–g were
  • artemisinic acid. Flow reactor system for multistep synthesis of (S)-rolipram. Pumps are labelled a, b, c, d and e; Labels A, B, C, D, E and F are flow lines. X are molecular sieves; Y is Amberlyst 15Dry; Z is Celite. (Reproduced with permission from [84], copyright 2015 Nature Publishing Group).
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Published 14 Mar 2017
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