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Search for "continuous flow system" in Full Text gives 23 result(s) in Beilstein Journal of Organic Chemistry.
C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis
Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43
- -situ imine formation is currently impossible with catalytic or stoichiometric amounts of amine due to decarbonylation of furfural under the reaction conditions [21]. We thus present here an adaptation of our Ru(0)-catalyzed C3-alkylation strategy of furfural derivatives to a continuous flow system
- reactants and catalyst. Initial tests with the commercial complex [Ru3(CO)12] at high temperature with different residence times provided the desired C3-alkylated imine I2a in NMR yields ranging from 30% to 65% (Table 1, entries 1–3 and Table S1 in Supporting Information File 1, p. S10). A continuous flow
- system was thus found to be compatible with the realization of this type of C‒H functionalization. This process led to a significant reduction of the reaction time compared to the batch, in particular by increasing the temperature to 200–250 °C, without significant losses of activity and selectivity
Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin
Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25
- and reduction. All reaction steps were studied separately and optimized under continuous flow conditions. After the optimization, the reaction steps were coupled in a semi-continuous flow system, since a solvent exchange had to be performed after the tosylation. However, the azidation and the
- ) were obtained (Table 3, entry 2). However, increasing the ratio of water in the solvent mixture afforded better results (Table 3, entries 3–6). The appropriate ratio of DMF/H2O was determined as 1:4, which gave NH2-β-CD (4) in a yield of 93% (Table 3, entry 5). Semi-continuous flow system for the
- with batch methods, it can be concluded that similar yields were obtained in both cases, however, under continuous flow conditions, the reaction time could be reduced from hours to minutes. Finally, we made an attempt to connect the three reaction steps with each other in a continuous flow system. It
Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies
Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70
- is important not only in the context of energy storage, CO2 reduction, and climate change prevention, but also because they provide a country-independent source of energy. However, for use in a continuous flow system, the catalyst must have extremely high SAR and catalytic activity. Recently, a
Rapid gas–liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide
Beilstein J. Org. Chem. 2022, 18, 660–668, doi:10.3762/bjoc.18.67
- highly productive process for industrial manufacturing. Investigation of epoxidation of cyclohexene with air in continuous flow system The flow system for the cyclohexene epoxidation with air was constructed and an investigation of flow conditions, temperature, and residence time was conducted
- performing the reaction in a continuous flow system. To the best of our knowledge, this is for the first time to achieve the epoxidation of cyclohexene using air within only 1.4 min by carefully avoiding any unwanted release which could result in a hazardous situation. In our flow conditions, the volume of
- . Conclusion In the present study, we developed the continuous flow system for the aerobic cyclohexene oxide production based on appropriate temperature and residence time control. Moreover, the production of cyclohexene oxide with high yield and selectivity was achieved under the conditions of a very short
Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography
Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27
- hand, we envisioned a system which would eliminate a further time-consuming unit operation, product purification. Inspired by recent reports of the incorporation of the Advion puriFlash 5.250 system in a continuous flow system [38], we aimed to apply this system to our flow setup. The puriFlash system
A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries
Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90
Heterogeneous photocatalysis in flow chemical reactors
Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125
Safe and highly efficient adaptation of potentially explosive azide chemistry involved in the synthesis of Tamiflu using continuous-flow technology
Beilstein J. Org. Chem. 2019, 15, 2577–2589, doi:10.3762/bjoc.15.251
- azidation reaction (Scheme 3). We herein present a comprehensive study on various mesyl shikimate 4 azidation procedures; with goal of safely and selectively making azide 5 in flow. Continuous flow C-3 mesyl shikimate azidation using sodium azide (NaN3). A continuous flow system fitted with a 19 µL reactor
- Chemtrix continuous-flow system (Figure 7). Mesyl shikimate (0.1 M) was treated with a mixture of either DPPA or TMSA (0.11 M, 1.1 equiv) and TEA (0.12 M, 1.2 equiv) in a continuous-flow system (Figure 7). The reaction was quenched with aqueous HCl (0.05 M, 0.5 equiv) within the flow system. Using DPPA as
- accompanied by a 6% conversion loss. TMSA was another azidating agent, which was investigated for mesyl shikimate azidation in a continuous-flow system (Figure 7). The reaction conversion and selectivity at varying conditions is presented graphically (Figure 11 and Figure 12). Just as with the other
A chemoselective and continuous synthesis of m-sulfamoylbenzamide analogues
Beilstein J. Org. Chem. 2017, 13, 303–312, doi:10.3762/bjoc.13.33
- CDCl3 with tetramethylsilane as internal standard or DMSO-d6 on a Bruker Avance III Nanobay 400 MHz spectrometer at room temperature. The automated continuous synthesis was conducted using a commercially available continuous-flow system (syrris AFRICA, Figure 2). Representative procedure for m
Continuous-flow synthesis of highly functionalized imidazo-oxadiazoles facilitated by microfluidic extraction
Beilstein J. Org. Chem. 2017, 13, 239–246, doi:10.3762/bjoc.13.26
- -oxadiazoles starting from carboxylic acids is reported. This process was applied to the multistep synthesis of imidazo[1,2-a]pyridin-2-yl-1,2,4-oxadiazoles, using a three reactor, multistep continuous-flow system without isolation of intermediates. This continuous-flow method was successfully combined with a
Self-optimisation and model-based design of experiments for developing a C–H activation flow process
Beilstein J. Org. Chem. 2017, 13, 150–163, doi:10.3762/bjoc.13.18
- algorithm would learn the response surface as fast as it was the case for its previous application. A framework of closed-loop or self-optimisation combining smart DoE algorithms, process analytics, chemoinformatics and automated reactor systems. Schematics of the automated continuous-flow system used for
Development of a continuous process for α-thio-β-chloroacrylamide synthesis with enhanced control of a cascade transformation
Beilstein J. Org. Chem. 2016, 12, 2511–2522, doi:10.3762/bjoc.12.246
- as an alternative solvent. As 1H NMR analysis indicated that the crude reaction product from batch tests (using methanol as solvent) consisted of 98% α-thioamide 2, the process was subsequently transferred to a continuous flow system (Scheme 5). A variety of temperatures (60–120 °C), bases (NaOMe
Synthesis and immunological evaluation of protein conjugates of Neisseria meningitidis X capsular polysaccharide fragments
Beilstein J. Org. Chem. 2014, 10, 2367–2376, doi:10.3762/bjoc.10.247
- to 3 min, 46 mg of the α-H-phosphonate 7 were obtained in 0.5 h at higher isolated yield (76%) and purity than batch reaction. Based on the maximum volume of the syringes employed in our continuous-flow system (5 mL, see Supporting Information File 1), we can estimate that a production rate of 2.2 g
Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions
Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325
- time. For a continuous flow system this can be defined in terms of the molar or volumetric flow rates (uM or uV), the conversion as a mol fraction (x) and the number of mol of substrate at the start of the reaction (nS) and the number of mol of catalyst (nCAT) as shown in Equation 1. The TOFs were also
- of the continuous flow system. The reactor shown is the 3.9 mm i.d. PFR. For the 1 mm i.d. reactor this was a coil of the 300 cm or 100 cm tube according to the specific reaction. Total conversion of 4-iodoanisole as a function of reactor run time for three reaction temperatures. Total conversion of
Temperature measurements with two different IR sensors in a continuous-flow microwave heated system
Beilstein J. Org. Chem. 2013, 9, 2079–2087, doi:10.3762/bjoc.9.244
- Uppsala, Sweden 10.3762/bjoc.9.244 Abstract In a continuous-flow system equipped with a nonresonant microwave applicator we have investigated how to best assess the actual temperature of microwave heated organic solvents with different characteristics. This is non-trivial as the electromagnetic field
- temperature under the influence of an electromagnetic field is not a trivial problem. In this evaluation we have used a fiber optic probe which allows the measurement of temperatures inside a reactor in a continuous-flow system using a nonresonant microwave heating device, and investigated two IR sensors as
Flow Giese reaction using cyanoborohydride as a radical mediator
Beilstein J. Org. Chem. 2013, 9, 1791–1796, doi:10.3762/bjoc.9.208
- precursors, ethyl acrylate as a radical trap, and sodium cyanoborohydride as a radical mediator, were examined in a continuous flow system. With the use of an automated flow microreactor, flow reaction conditions for the Giese reaction were quickly optimized, and it was found that a reaction temperature of
- 70 °C in combination with a residence time of 10–15 minutes gave good yields of the desired addition products. Keywords: continuous flow system; cyanoborohydride; flow chemistry; iodoalkanes; microreactor; tin-free Giese reaction; Introduction Organo halides are among the most useful precursors to
Continuous-flow hydration–condensation reaction: Synthesis of α,β-unsaturated ketones from alkynes and aldehydes by using a heterogeneous solid acid catalyst
Beilstein J. Org. Chem. 2011, 7, 1680–1687, doi:10.3762/bjoc.7.198
- was purified by column chromatography (n-hexane/DCM [2:1 to 1:1]). The schematic arrangement of the continuous-flow system. Preparation of chalcone 3b on larger scale. Optimization of hydration–condensation reactions.a Flow hydration–condensation of alkynes 1 and aldehydes 2.a Supporting Information
Continuous proline catalysis via leaching of solid proline
Beilstein J. Org. Chem. 2011, 7, 1671–1679, doi:10.3762/bjoc.7.197
- , use and management of solids [30][31][32][33] and reactions [34][35] in flow as well as in proline catalysis [36][37]. This prompted us to consider new strategies for the implementation of proline in a continuous-flow system without resorting to proline analogues or tethered catalysts [38][39][40
Koch–Haaf reaction of adamantanols in an acid-tolerant hastelloy-made microreactor
Beilstein J. Org. Chem. 2011, 7, 1288–1293, doi:10.3762/bjoc.7.149
- : continuous flow system; hastelloy; Koch–Haaf reaction; microreactor; Introduction The recent evolution of microreactor technology has allowed synthetic chemists to use this precisely sophisticated reaction apparatus in place of the well-established glassware batch flask [1][2][3][4][5][6][7][8][9][10
Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor
Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59
- continuous flow system, synthetic intermediates can be generated and consumed in situ, which eliminates the need to store toxic, reactive or explosive intermediates and thus makes the synthetic protocol safer. However, initial attempts to convert the azide–nitrile cycloaddition protocols to a high
Continuous flow enantioselective arylation of aldehydes with ArZnEt using triarylboroxins as the ultimate source of aryl groups
Beilstein J. Org. Chem. 2009, 5, No. 56, doi:10.3762/bjoc.5.56
- continuous flow enantioselective processes [52] are still scarce [22][53][54][55][56][57] in spite of the enormous potential of this methodology. Herein, we report the development of a continuous flow system for the preparation of enantioenriched diarylmethanols using triarylboroxins as the ultimate aryl
- 89% ee. Continuous flow system System set-up For the continuous flow experiments, a system similar to that previously described for the enantioselective ethylation of aldehydes [23] was used (Figure 3). The flow reactor consists of a vertically mounted, fritted and jacketed low-pressure
- of reagents for the generation of PhZnEt, the observed enantioselectivities were comparable to those recorded with the homogeneous catalyst 1. Thus, further improvement of the present continuous flow system could possibly be achieved with the use of alternative sources of the arylating species [33
Radical carbonylations using a continuous microflow system
Beilstein J. Org. Chem. 2009, 5, No. 34, doi:10.3762/bjoc.5.34
- pressurized carbon monoxide gas. Good to excellent yields of carbonylated products were obtained via radical formylation, carbonylative cyclization and three-component coupling reactions, using tributyltin hydride or TTMSS as a radical mediator. Keywords: continuous flow system; microreactor; radical
Asymmetric reactions in continuous flow
Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19
- advantage of a continuous flow system, the resolution of a mixture of the racemic acetyl-amino acid (DL-58) was carried out in tandem with a microextractor for the selective separation of the resulting chiral products (Scheme 17). The racemic substrate was introduced into the microreactor in a buffered
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