Homogeneous continuous flow nitration of O-methylisouronium sulfate and its optimization by kinetic modeling

• Jiapeng Guo,
• Weike Su and
• An Su

Beilstein J. Org. Chem. 2024, 20, 2408–2420, doi:10.3762/bjoc.20.205

• effects of mass and heat transfer. According to the mixing principle, there are active mixers and passive mixers. Passive mixers do not require overly complex equipment and external energy inputs and are extensively used in continuous flow reactions [20][21]. Passive mixers enhance the passive mixing of

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

• János Máté Orosz,
• Dóra Ujj,
• Petr Kasal,
• Gábor Benkovics and
• Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

• processes in the pharmaceutical industry [1][27]. During continuous flow reactions, the target molecules can be produced with better purity, selectivity and in higher yields, as well as in consistent quality due to the precise parameter control, low volume ratio and small quantities. The temperature control

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• routinely employed in both industry and academia, examples of such systems integrated in continuous flow reactions are scarce. Recently, two protocols were reported that use an Advion puriFlash® 5.250 system for continuous purifications [37][38]. The puriFlash® system is an automated liquid chromatography

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• consisting of O-allylation and Claisen rearrangement for the continuous synthesis of 2-allyl-4,6-difluorophenol (SiC = silicon carbide) [52]. Continuous flow reactions and comparison with batch reaction (oil bath). A. Pd-catalyzed transfer hydrogenations using ethanol in cyclohexene [53], B. multicomponent

• reactions. Continuous flow reactions and comparison with batch reaction (oil bath). A. pericyclic reactions and B. Pd-catalyzed reactions. Reactions under flow conditions using inductively heated fixed-bed materials serving as stoichiometric reagents. Reactions under flow conditions using inductively heated

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Recent advances in palladium-catalysed asymmetric 1,4–additions of arylboronic acids to conjugated enones and chromones

• Jan Bartáček,
• Jan Svoboda,
• Martin Kocúrik,
• Jaroslav Pochobradský,
• Alexander Čegan,
• Miloš Sedlák and
• Jiří Váňa

Beilstein J. Org. Chem. 2021, 17, 1048–1085, doi:10.3762/bjoc.17.84

• , continuous-flow reactions are currently a general challenge, especially for the pharmaceutical industry. The prerequisite for a successful continuous synthesis in the field of asymmetric addition reactions to enones is the mastery of recyclable heterogeneous catalysis. Very recently, we reported [57] the

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

• . Continuous-flow reactions were performed on a Labtrix® Start system and a Uniquis FlowSyn system. Reactions were monitored by Agilent 1200 high-performance liquid chromatography (HPLC) fitted with a UV–vis detector. HPLC analysis was performed on Agilent Zorbax C18-column (250 mm × 4.6 mm i.d, 5 µm) ambient

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

• could be used if precipitates are formed during a reaction which is often a problem in continuous flow reactions [33]. For mechanically mixing, a small magnetic stirring bar was placed in the reactor during printing. These reactors were used for the premixing of reactants or for the extraction steps

A general and atom-efficient continuous-flow approach to prepare amines, amides and imines via reactive N-chloramines

• Katherine E. Jolley,
• Michael R. Chapman and
• A. John Blacker

Beilstein J. Org. Chem. 2018, 14, 2220–2228, doi:10.3762/bjoc.14.196

• provide a tres for optimal conversion. This was achieved according to reaction kinetics and hydrophobicity of the amine, which affects its partition between phases. Herein, we report improvements to this process and the use of N-alkyl-N-chloramine in subsequent continuous-flow reactions (Figure 1). These

Diels–Alder reactions of myrcene using intensified continuous-flow reactors

• Christian H. Hornung,
• Miguel Á. Álvarez-Diéguez,
• Thomas M. Kohl and
• John Tsanaktsidis

Beilstein J. Org. Chem. 2017, 13, 120–126, doi:10.3762/bjoc.13.15

• tubes might have occurred, however, this could not be confirmed. Further details on these observations can be found in Supporting Information File 1. Using 13C NMR an approximate ratio of the two isomers, 3-3 and 3-4 (see Figure 2), was calculated for the continuous-flow reactions performed between 140

Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification

• Anna Zaghi,
• Daniele Ragno,
• Graziano Di Carmine,
• Carmela De Risi,
• Olga Bortolini,
• Pier Paolo Giovannini,
• Giancarlo Fantin and
• Alessandro Massi

Beilstein J. Org. Chem. 2016, 12, 2719–2730, doi:10.3762/bjoc.12.268

• dedicated reactor (Biotage InitiatorTM). Reactions were performed with temperature-controlled programs in glass vials (0.5–2 mL) sealed with a Teflon septum. Temperatures were measured externally by an IR sensor. As described in [32], the system used for continuous-flow reactions was composed of an HPLC

Continuous-flow synthesis of primary amines: Metal-free reduction of aliphatic and aromatic nitro derivatives with trichlorosilane

• Riccardo Porta,
• Alessandra Puglisi,
• Giacomo Colombo,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2016, 12, 2614–2619, doi:10.3762/bjoc.12.257

• procedure for continuous-flow reactions, products characterization and NMR spectra of the compounds. Acknowledgements A.P. thanks the University of Milan for the grant “Piano di Sostegno alla Ricerca 2015-17 - LINEA 2 Azione A (Giovani Ricercatori)”. M.B. thanks the University of Milan for the Transition

Continuous-flow Heck synthesis of 4-methoxybiphenyl and methyl 4-methoxycinnamate in supercritical carbon dioxide expanded solvent solutions

• Phei Li Lau,
• Ray W. K. Allen and
• Peter Styring

Beilstein J. Org. Chem. 2013, 9, 2886–2897, doi:10.3762/bjoc.9.325

• prepared and stirred thoroughly until completely mixed. The ratio of organic to scCO2 used in the autoclave corresponded to the 5:1 volumetric ratio used in the continuous flow reactions. The tetrahydrofuran and methanol were used to dissolve the organo iodide and act as a miscible, polar modifier to

• . The resulting organic mixture (top layer) was then withdrawn and dried over magnesium sulfate then analysed by gas chromatography using a Varian 3900 GC with reference to standard solutions of trans-4-methoxystilbene. Continuous flow reactions Particles of the catalyst, 2% Pd on silica, (250 mg

• flow reactions All reactions were performed in 300 or 100 cm stainless steel tubular plug flow reactors (PFRs) of 1 mm internal diameter. A larger diameter (3.9 mm) PFR was also used as a comparison in one example (Figure 2). Initial studies used flow rates commensurate with the concentration used in

One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

• Mark C. Bagley,
• Vincenzo Fusillo,
• Robert L. Jenkins,
• M. Caterina Lubinu and
• Christopher Mason

Beilstein J. Org. Chem. 2013, 9, 1957–1968, doi:10.3762/bjoc.9.232

• recent advent of new technology for mesoscale microwave-assisted continuous flow reactions [30], we set out to establish if readily-available ethynyl carbonyl precursors were capable of delivering diverse heterocyclic targets under a continuous flow regime under microwave heating. Ley and Baxendale et al

Flow Giese reaction using cyanoborohydride as a radical mediator

• Takahide Fukuyama,
• Takuji Kawamoto,
• Mikako Kobayashi and
• Ilhyong Ryu

Beilstein J. Org. Chem. 2013, 9, 1791–1796, doi:10.3762/bjoc.9.208

• automated microflow reactor [32], which revealed that running the continuous flow reactions at 70 °C for 10–15 min gave good yields of Giese addition products with effective suppression of the byproducts. Results and Discussion We employed an automated microflow reactor system, MiChS® System X-1 [33

Controlled synthesis of poly(3-hexylthiophene) in continuous flow

• Helga Seyler,
• Jegadesan Subbiah,
• David J. Jones,
• Andrew B. Holmes and
• Wallace W. H. Wong

Beilstein J. Org. Chem. 2013, 9, 1492–1500, doi:10.3762/bjoc.9.170

• evidence for the quasi-living nature [21] of the polymerization in flow processing (Table 1 and Figure 1). In fact, the molecular-weight data obtained in conventional batch reactions were very similar to those recorded in continuous-flow reactions (Figure 1). Matrix-assisted laser desorption ionization

Continuous-flow catalytic asymmetric hydrogenations: Reaction optimization using FTIR inline analysis

• Magnus Rueping,
• Teerawut Bootwicha and
• Erli Sugiono

Beilstein J. Org. Chem. 2012, 8, 300–307, doi:10.3762/bjoc.8.32

• loading to 0.1 mol % resulted in a significant drop in chemical yield, affording the product in lower yield while enantioselectivity was maintained (Table 3, entry 6). Although continuous-flow reactions provide many advantages, in certain cases it can be beneficial to conduct reactions under classical

Continuous gas/liquid–liquid/liquid flow synthesis of 4-fluoropyrazole derivatives by selective direct fluorination

• Jessica R. Breen,
• Graham Sandford,
• Dmitrii S. Yufit,
• Judith A. K. Howard,
• Jonathan Fray and
• Bhairavi Patel

Beilstein J. Org. Chem. 2011, 7, 1048–1054, doi:10.3762/bjoc.7.120

• : continuous flow reactions; fluorine; fluoropyrazole; gas-liquid flow reactor; selective direct fluorination; Introduction Organic systems which bear fluorine atoms are used in an ever widening range of applications in the life sciences. Many commercially significant pharmaceutical and agrochemical products

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• were found to be comparable to the analogous reaction carried out in batch under homogeneous conditions. Multiple runs (each lasting 5–8 h) were performed in the reactors with consistent results during as well as between each run. These continuous flow reactions were first conducted in CH2Cl2 and neat