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Search for "flow chemistry" in Full Text gives 111 result(s) in Beilstein Journal of Organic Chemistry.
Flow synthesis of a versatile fructosamine mimic and quenching studies of a fructose transport probe
Beilstein J. Org. Chem. 2013, 9, 2022–2027, doi:10.3762/bjoc.9.238
- NBDM, enabling us to measure key photophysical properties that will facilitate future uptake studies. Keywords: flow chemistry; fructose mimic; gluts; NBDM; Introduction The impact of dietary fructose on human health is not well-understood. A growing body of work suggests that those eating diets high
- flow chemistry challenge. The output from the oxime step contains excess hydroxylamine and salts carried from the first step that poisoned the packed-bed catalyst we screened. In theory, continuous purification could remove these materials but existing strategies do not enable removal of water soluble
Microflow photochemistry: UVC-induced [2 + 2]-photoadditions to furanone in a microcapillary reactor
Beilstein J. Org. Chem. 2013, 9, 2015–2021, doi:10.3762/bjoc.9.237
- chemistry; furanone; microflow chemistry; photochemistry; Introduction Continuous-flow chemistry has recently emerged as a new methodology in organic chemistry [1][2][3][4]. The combination of microstructured dimensions and flow operations has also proven advantageous for photochemical applications [5][6
- test tube. The microcapillary unit had a 9-times larger surface-to-volume ratio, which resulted in a more efficient harvest of the available light. The results contribute to the growing field of ‘microflow photochemistry’ [5][6][7][8][9] and ‘green flow chemistry’ [42][43][44][45]. It is hoped that
- photoreactor equipped with low wattage UVC-lamps. Conversion rates and isolated yields were compared to analogue batch reactions in a quartz test tube. In all cases examined, the microcapillary reactor furnished faster conversions and improved product qualities. Keywords: cycloaddition; cyclobutane; flow
One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor
Beilstein J. Org. Chem. 2013, 9, 1957–1968, doi:10.3762/bjoc.9.232
- -substituted propargyl aldehydes undergo Hantzsch dihydropyridine synthesis in preference to Bohlmann–Rahtz reaction in a very high yielding process that is readily transferred to continuous flow processing. Keywords: Bohlmann–Rahtz; continuous flow processing; ethynyl ketones; flow chemistry; Hantzsch
- microwave-assisted transformations under flow processing have greatly expanded the range of chemistries scaled up and evaluated using this technology [1][9][16][33][34][35][36][37][38][39][40][41][42]. With all of these developments, it is becoming increasingly clear that flow chemistry, and to some degree
- microwave flow chemistry, is realizing its potential towards the next evolutionary step in synthetic chemistry [43]. In 2005 we described a new continuous flow reactor design for microwave-assisted synthesis that operates in the optimum standing-wave cavity of a proprietary instrument [44]. The principal
Continuous flow photocyclization of stilbenes – scalable synthesis of functionalized phenanthrenes and helicenes
Beilstein J. Org. Chem. 2013, 9, 1883–1890, doi:10.3762/bjoc.9.221
- backbone functionalized phenanthrenes and helicenes of various sizes in good yields. Keywords: continuous-flow reactor; flow chemistry; helicenes; light-driven cyclization reaction; photocyclization; stilbenes; Introduction Phenanthrenes are versatile intermediates toward polycyclic aromatic hydrocarbons
Raman spectroscopy as a tool for monitoring mesoscale continuous-flow organic synthesis: Equipment interface and assessment in four medicinally-relevant reactions
Beilstein J. Org. Chem. 2013, 9, 1843–1852, doi:10.3762/bjoc.9.215
- industry on production scales. In a research and development setting, there has been increasing interest in using flow chemistry on smaller scales. To this end, a wide range of companies now produce equipment for both micro- and mesofluidic flow chemistry [1][2]. Some of the advantages of these devices are
- increased experimental safety, easy scale-up and thorough mixing of reagents [3][4][5][6][7]. It is not surprising, therefore, that a wide range of synthetic chemistry transformations have been reported using this equipment [8][9]. When it comes to evaluating the outcome of reactions performed using flow
- chemistry and optimizing reaction conditions, one option is to use inline product analysis. This opens the avenue for fast, reliable assay in comparison with the traditional approach in which performance is evaluated based on offline product analysis. When interfaced with microreactors, inline analysis has
Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping
Beilstein J. Org. Chem. 2013, 9, 1837–1842, doi:10.3762/bjoc.9.214
- ; cycloaddition; Diels–Alder reaction; flow chemistry; gas chromatography; on-column reaction gas chromatography; Introduction The combination of synthesis and analysis in a single experiment offers many advantages. Time-consuming steps, i.e. work-up and separation of the reaction products, can be minimized, and
Ethyl diazoacetate synthesis in flow
Beilstein J. Org. Chem. 2013, 9, 1813–1818, doi:10.3762/bjoc.9.211
- ); flow chemistry; microreactor technology; Introduction Diazo compounds are frequently used versatile building blocks in organic chemistry [1][2]. From this class of compounds diazomethane and ethyl diazoacetate (1, EDA) are arguably the synthetically most useful ones. Due to the potentially explosive
Flow Giese reaction using cyanoborohydride as a radical mediator
Beilstein J. Org. Chem. 2013, 9, 1791–1796, doi:10.3762/bjoc.9.208
- 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
The application of a monolithic triphenylphosphine reagent for conducting Ramirez gem-dibromoolefination reactions in flow
Beilstein J. Org. Chem. 2013, 9, 1781–1790, doi:10.3762/bjoc.9.207
- application of a monolithic form of triphenylphosphine to the Ramirez gem-dibromoolefination reaction using flow chemistry techniques is reported. A variety of gem-dibromides were synthesised in high purity and excellent yield following only removal of solvent and no further off-line purification. It is also
- possible to perform the Appel reaction using the same monolith and the relationship between the mechanisms of the two reactions is discussed. Keywords: bromination; flow chemistry; Ramirez gem-dibromoolefination reaction; solid-supported reagent; triphenylphosphine monolith; Introduction The advantages
- of applying flow chemistry processing to organic synthesis have been extensively demonstrated in the literature, increasing the safety, efficiency and reproducibility of many organic chemistry reactions, causing this technology to be accepted as an important new tool to aid the modern research
[3 + 2]-Cycloadditions of nitrile ylides after photoactivation of vinyl azides under flow conditions
Beilstein J. Org. Chem. 2013, 9, 1745–1750, doi:10.3762/bjoc.9.201
- from the corresponding vinyl azide. Keywords: azirines; cycloaddition; flow chemistry; flow reactors; inductive heating; nitrile ylides; photochemistry; vinyl azides; Introduction Recently, photochemistry has seen a renaissance despite the fact that under batch conditions specialized reaction vessels
- photochemical process can efficiently be achieved. These facts led us to initiate an investigation on the photochemical activation of vinyl azides and the trapping of the intermediate nitrile ylides 3 [19] by different dipolarophiles exploiting the advantages of photo flow-chemistry [20][21]. Here, we report on
Gallium-containing polymer brush film as efficient supported Lewis acid catalyst in a glass microreactor
Beilstein J. Org. Chem. 2013, 9, 1698–1704, doi:10.3762/bjoc.9.194
- model substrate, and for the formation of oxazoles by ring closure of ortho-hydroxy oximes. The catalytic activity of the microreactor could be maintained by periodic reactivation by treatment with GaCl3. Keywords: dehydration of oximes; flow chemistry; gallium; microreactors; Lewis acid catalysis
Chemistry in flow systems III
Beilstein J. Org. Chem. 2013, 9, 1696–1697, doi:10.3762/bjoc.9.193
- Andreas Kirschning Leibniz University of Hannover, Schneiderberg 1B, 30167 Hannover, Germany 10.3762/bjoc.9.193 Keywords: flow chemistry; The third Thematic Series on flow chemistry published in the Beilstein Journal of Organic Chemistry demonstrates the emerging importance of transforming
- these aspects can be found in this third Thematic Series on flow chemistry. I am thankful to all my colleagues who contributed with their excellent research to this issue. The Beilstein Team is acknowledged for the handling of the manuscripts and referee reports in a very pleasant and professional
The rapid generation of isothiocyanates in flow
Beilstein J. Org. Chem. 2013, 9, 1613–1619, doi:10.3762/bjoc.9.184
- chemical transformation which typically eliminates the requirements for any conventional work-up or purification of the reaction stream. Keywords: chloroxime; dipolar cycloaddition; flow chemistry; flow synthesis; immobilised reagents; isothiocyanate; nitrile oxide; Introduction Flow based chemical
- ]. Indeed, flow chemistry is moving from an academic curiosity to become a common tool in many synthesis laboratories paralleling the emergence and adoption of another enabling technology, the microwave reactor [17]. An area which has benefited significantly from the many recent developments in our
- understanding of flow chemistry is the synthesis of reactive precursors and handling of sensitive intermediates [18][19][20][21][22][23]. However, despite the breadth of chemistries already explored there are certain functional transformations notably absent, one particular class of important building blocks
Efficient continuous-flow synthesis of novel 1,2,3-triazole-substituted β-aminocyclohexanecarboxylic acid derivatives with gram-scale production
Beilstein J. Org. Chem. 2013, 9, 1508–1516, doi:10.3762/bjoc.9.172
- safe and straightforward way. The obtained 1,2,3-triazole-substituted β-aminocyclohexanecarboxylates can be regarded as interesting precursors for drugs with possible biological effects. Keywords: β-amino acids; click chemistry; continuous-flow; copper; flow chemistry; triazoles; Introduction In
- to be environmentally benign technologies [48]. In consequence of these benefits, flow chemistry-based techniques have exerted a significant impact on modern synthetic chemistry, ranging from laboratory-based experiments to industrial-scale production. Here, we describe a safe and efficient CF
Controlled synthesis of poly(3-hexylthiophene) in continuous flow
Beilstein J. Org. Chem. 2013, 9, 1492–1500, doi:10.3762/bjoc.9.170
- : conjugated polymers; continuous-flow synthesis; controlled polymerization; flow chemistry; organic solar cell materials; Introduction Poly(3-hexylthiophene), P3HT, is the most investigated material in bulk heterojunction (BHJ) organic solar cells (OSC) [1]. The reasons for its dominance in the field include
Hypervalent iodine/TEMPO-mediated oxidation in flow systems: a fast and efficient protocol for alcohol oxidation
Beilstein J. Org. Chem. 2013, 9, 1437–1442, doi:10.3762/bjoc.9.162
- successfully achieved by using microreactor technology. This method can be used as an alternative for the oxidation of various alcohols achieving excellent yields and selectivities in significantly shortened reaction times. Keywords: alcohols; carbonyl compounds; flow chemistry; microreactor; oxidation
- shortened reaction times. Several other oxidative processes have already been reported in flow chemistry [16]. Results and Discussion Benzyl alcohol was chosen as a substrate in order to examine the efficiency of the reaction and the microreactor flow system. In a batch reaction, the mixture of benzyl
Simple and rapid hydrogenation of p-nitrophenol with aqueous formic acid in catalytic flow reactors
Beilstein J. Org. Chem. 2013, 9, 1156–1163, doi:10.3762/bjoc.9.129
- was reduced via hydrogen transfer from formic acid to p-nitrophenol and not by hydrogen generated by dehydrogenation of formic acid. Keywords: catalytic tubular reactor; flow chemistry; formic acid; hydrogenation; p-aminophenol; p-nitrophenol; Introduction The flow reaction process enables
Camera-enabled techniques for organic synthesis
Beilstein J. Org. Chem. 2013, 9, 1051–1072, doi:10.3762/bjoc.9.118
- of the future. Keywords: automation; computer vision; digital camera; flow chemistry; machine-assisted synthesis; Introduction The increasing prevalence of digital camera technology for capturing images, videos and visible information is having a profound impact on many aspects of our modern
- , traditional research facilities are extremely expensive to commission and run, and yet for a significant proportion of their lives they are under-used or even lying vacant. To overcome some of these inefficient practices, continuous processing methods such as flow chemistry [26][27][28][29][30][31][32] and
3D-printed devices for continuous-flow organic chemistry
Beilstein J. Org. Chem. 2013, 9, 951–959, doi:10.3762/bjoc.9.109
- processing advantages of flow chemistry for the synthesis of organic compounds. Robust and inexpensive 3D-printed reactionware devices are easily connected using standard fittings resulting in complex, custom-made flow systems, including multiple reactors in a series with in-line, real-time analysis using an
- ATR-IR flow cell. As a proof of concept, we utilized two types of organic reactions, imine syntheses and imine reductions, to show how different reactor configurations and substrates give different products. Keywords: 3D printing; flow chemistry; flow IR; in-line analysis; imine reduction; imine
- synthesis; millifluidics; reactionware; Introduction The use of flow chemistry and 3D-printing technology is expanding in the field of organic synthesis [1][2][3][4][5]. The application of continuous-flow systems is frequently found in chemistry, and is beginning to have a significant impact on the way
Flow photochemistry: Old light through new windows
Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229
- be made. Keywords: cycloaddition; flow chemistry; photocatalysis; photochemistry; photooxygenation; Introduction The use of ultraviolet light to carry out bond-forming reactions in synthetic organic chemistry has a long history dating back to the mid-19th century. The observation by Trommsdorff [1
- not generally think photo-retrosynthetically. As a result potentially shorter and more efficient synthetic routes to complex organic molecules, as well as access to new molecular space have long been avoided by mainstream synthetic chemists. Flow to the rescue? Over the last 15 years flow chemistry
- of bulk solutions, which combined with the extremely short lifetime of singlet oxygen means that lengthy irradiations are often required. These issues can be overcome through the use of continuous-flow chemistry: reactions performed in this manner have only a small amount of oxygenated solvent and
Photochemistry with laser radiation in condensed phase using miniaturized photoreactors
Beilstein J. Org. Chem. 2012, 8, 1213–1218, doi:10.3762/bjoc.8.135
- . Keywords: azides; chemical diversity; flow chemistry; heterocycles; laser; micro reactor; Introduction Classical combinatorial chemistry [1][2] approaches usually aim at the synthesis of multi-milligram amounts of new compounds to extend screening decks used in multiple screening campaigns [3]. An
- alternative method enabled by the maturing microreaction technology and the use of flow chemistry [4][5][6] is the integration of synthesis and screening in one integrated lab-on-a-chip approach [7]. Using this methodology we have integrated photochemistry in a miniaturized reaction setup to enable
- combinatorial flow chemistry in lab-on-a-chip applications. Photochemical processes are in this case particularly interesting because of their enhanced molecular activation [8]. Photochemistry in microreactors is an emerging research area [9], and especially photocatalytic reactions have been investigated in
Continuous proline catalysis via leaching of solid proline
Beilstein J. Org. Chem. 2011, 7, 1671–1679, doi:10.3762/bjoc.7.197
- . Keywords: aminoxylation; flow chemistry; heterogeneous catalysis; packed-bed microreactor; proline/thiourea catalysis; Introduction Continuous flow chemistry [1][2][3], performed in small dimension tubing or channels, differs from batch chemistry in that mixing and heat transfer are significantly faster
The application of a monolithic triphenylphosphine reagent for conducting Appel reactions in flow microreactors
Beilstein J. Org. Chem. 2011, 7, 1648–1655, doi:10.3762/bjoc.7.194
- 2NY, UK 10.3762/bjoc.7.194 Abstract Herein we describe the application of a monolithic triphenylphosphine reagent to the Appel reaction in flow-chemistry processing, to generate various brominated products with high purity and in excellent yields, and with no requirement for further off-line
- purification. Keywords: Appel reaction; bromination; flow chemistry; solid-supported reagent; triphenylphosphine monolith; Introduction Flow chemistry is well-established as a useful addition to the toolbox of the modern research chemist, with advantages accrued through increased efficiency, reproducibility
- ideal for use in a flow-chemistry setup. Elemental analysis showed an approximate loading of 1.87 mmol of phosphorus per gram, giving a calculated loading of 4.68 mmol of phosphorus per monolith, which is comparable to commercially available triphenylphosphine resins. Loading the monolith The monolith
Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline
Beilstein J. Org. Chem. 2011, 7, 1486–1493, doi:10.3762/bjoc.7.172
- alternative for improving the productivity of catalytic species results from the implementation of heterogenized catalysts in continuous-flow reactors. Flow chemistry has experienced a very important development in the last ten years as an emerging technology for organic synthesis [51][52][53][54][55][56][57
- ][58][59][60][61][62][63][64][65][66]. It offers as its main advantages facile automation and excellent heat and mass transfer, rendering the scale-up of a process a trivial task, in contrast with the obstacles always met in the scale-up of batch processes [67][68][69][70][71]. The combination of flow
- chemistry with solid-supported catalysts allows the advantages inherent to both technologies to be added together. Thus, the physical immobilization of the catalyst in a packed-bed reactor allows it to be submitted constantly to the reaction conditions, avoiding possible degradation of the catalyst during
Multistep flow synthesis of vinyl azides and their use in the copper-catalyzed Huisgen-type cycloaddition under inductive-heating conditions
Beilstein J. Org. Chem. 2011, 7, 1441–1448, doi:10.3762/bjoc.7.168
- requires further optimization. This and other examples [11][12][13] principally demonstrate that flow chemistry is an ideal enabling technology [14] for generating and utilizing hazardous azido reagents because only small amounts are generated at a time and are subsequently consumed in situ. The other
- benefits of flow chemistry, when working with highly reactive reagents, are the better heat-transfer characteristics due to a larger surface-to-volume ratio, as well as the increased mixing efficiency [15][16][17][18][19][20][21][22][23][24]. To practically eliminate the generation of explosive iodine
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