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

• been also described [24][25]. Continuous flow approaches have already attracted much attention in the oil, plastic, and fine chemical industries [26]. The vision of faster, safer, cheaper, more flexible and robust production also initiated the paradigm shift from batch reactions to continuous flow

• 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

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

• dioxide (core-shell nanostructured particles), called MagSilicaTM to be used as fixed-bed materials in many different continuous flow processes (Figure 4A) [50]. These materials are excited very rapidly in a medium frequency (25 kHz) electromagnetic field, heating reaction mixtures in packed bed reactors

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

Coupling biocatalysis with high-energy flow reactions for the synthesis of carbamates and β-amino acid derivatives

• Alexander Leslie,
• Thomas S. Moody,
• Megan Smyth,
• Scott Wharry and
• Marcus Baumann

Beilstein J. Org. Chem. 2021, 17, 379–384, doi:10.3762/bjoc.17.33

• within continuous flow processes [17][18][19][20] to provide a greener and more chemoselective means for the synthesis of drug-like targets. Recently, we reported on an innovative telescoped process using immobilized CALB (Candida antarctica lipase B) to enable the conversion of residual benzyl alcohol

• -based aza-Michael addition reactions. This novel approach allows for the creation of important chemical building blocks whilst demonstrating a new use of biocatalysts in continuous flow processes. Scope of Cbz-carbamate products obtained via flow process (*tRes = 60 min, **T = 80 °C; isolated yields

Photocatalyic Appel reaction enabled by copper-based complexes in continuous flow

• Clémentine Minozzi,
• Jean-Christophe Grenier-Petel,
• Shawn Parisien-Collette and
• Shawn K. Collins

Beilstein J. Org. Chem. 2018, 14, 2730–2736, doi:10.3762/bjoc.14.251

• adapted to continuous flow using purple LED reactors. The batch and continuous flow processes were all made possible due to the ability to screen highly modular copper-based complexes for photocatalysis. Alcohol→bromide functional group transformations. Ligands used in the library generation of

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

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

• recycle experiment paved the way for the application of 5 in continuous-flow processes with long-term stability. Next, the heterogeneous procedure for the activation of aromatic α-diketones was applied to the model Stetter-like reaction of benzil 1a with chalcone 9a serving as activated α,β-unsaturated

Supported bifunctional thioureas as recoverable and reusable catalysts for enantioselective nitro-Michael reactions

• José M. Andrés,
• Miriam Ceballos,
• Alicia Maestro,
• Isabel Sanz and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2016, 12, 628–635, doi:10.3762/bjoc.12.61

• transformations [1][2][3][4][5]. In these processes one of the major problems is related to the recovering of the catalysts. The support of the small molecules on different materials has been proposed as a solution, including their use in continuous flow processes [6][7][8][9]. The most popular supports include

Camera-enabled techniques for organic synthesis

• Steven V. Ley,
• Richard J. Ingham,
• Matthew O’Brien and
• Duncan L. Browne

Beilstein J. Org. Chem. 2013, 9, 1051–1072, doi:10.3762/bjoc.9.118

• early stages of development were heavily influenced by a consideration of the potential for automated visual monitoring, and indeed this visual monitoring technique co-evolved with the gas-flow reactor as we assessed different gases and their potential reactivity in continuous flow processes. The

Flow photochemistry: Old light through new windows

• Jonathan P. Knowles,
• Luke D. Elliott and
• Kevin I. Booker-Milburn

Beilstein J. Org. Chem. 2012, 8, 2025–2052, doi:10.3762/bjoc.8.229

Aryl nitrile oxide cycloaddition reactions in the presence of pinacol boronic acid ester

• Sarah L. Harding,
• Sebastian M. Marcuccio and
• G. Paul Savage

Beilstein J. Org. Chem. 2012, 8, 606–612, doi:10.3762/bjoc.8.67

• ], and continuous-flow processes [3][4]. An important consideration when using these reactions for multistep syntheses is whether they are chemically compatible, without having to resort to protection/deprotection systems. For example, to generate a library of 3-bi(hetero)aryl isoxazoline analogues 3 a

Continuous-flow hydration–condensation reaction: Synthesis of α,β-unsaturated ketones from alkynes and aldehydes by using a heterogeneous solid acid catalyst

• Magnus Rueping,
• Teerawut Bootwicha,
• Hannah Baars and
• Erli Sugiono

Beilstein J. Org. Chem. 2011, 7, 1680–1687, doi:10.3762/bjoc.7.198

• reactor; green chemistry; heterogeneous catalysis, microwave; Introduction In recent years, the development of continuous-flow technologies has expanded considerably and has had a significant impact on modern organic synthetic chemistry. Continuous-flow processes offer advantages, such as operational

Continuous proline catalysis via leaching of solid proline

• Suzanne M. Opalka,
• Ashley R. Longstreet and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2011, 7, 1671–1679, doi:10.3762/bjoc.7.197

• ]. With researchers becoming increasingly interested in developing continuous-flow processes, the rapid assessment of catalyst conditions necessary for potential synthetic routes requires a simple approach to deal with limited-solubility catalysts. We have both a long-standing interest in the production

Efficient and selective chemical transformations under flow conditions: The combination of supported catalysts and supercritical fluids

• M. Isabel Burguete,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2011, 7, 1347–1359, doi:10.3762/bjoc.7.159

• to a limited number of fields, a significant development in this area can be envisaged for the near future due to the clear advantages of these systems over the conventional ones. Keywords: biphasic systems; continuous flow processes; enantioselective catalysis; immobilized catalysts; polymer

• potential of biphasic ILs–scCO2 systems. Indeed, this system was further implemented by the same authors to obtain a fully continuous process [20]. In this context, a simple approach to implement biphasic ILs–scCO2 systems into continuous flow processes is to absorb the ILs on a porous support material

• approach is attractive because it combines acid heterogeneous catalysts, as an environmentally and economically acceptable alternative to conventional homogeneous catalysts such as H2SO4 and HF, with the advantages of scFs. Thus, simple fixed-bed reactors can be developed for carrying out continuous flow

Scaling up of continuous-flow, microwave-assisted, organic reactions by varying the size of Pd-functionalized catalytic monoliths

• Ping He,
• Stephen J. Haswell,
• Paul D. I. Fletcher,
• Stephen M. Kelly and
• Andrew Mansfield

Beilstein J. Org. Chem. 2011, 7, 1150–1157, doi:10.3762/bjoc.7.133

• where the reactants are present in the irradiation chamber for a short period of time [18][19]. Therefore, the application of microwave chemistry to scalable, continuous-flow processes, with commercially available microwave equipment and suitable flow instrumentation, is becoming increasingly important

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

• established that, in both batch and continuous flow processes, 1,3-dicarbonyl derivatives are not equally reactive towards fluorine gas [12] and that the ease of selective direct fluorination depends on the nature and proximity of other functional groups. Substrates that have a high initial equilibrium enol

Unusual behavior in the reactivity of 5-substituted-1H-tetrazoles in a resistively heated microreactor

• Bernhard Gutmann,
• Toma N. Glasnov,
• Tahseen Razzaq,
• Walter Goessler,
• Dominique M. Roberge and
• C. Oliver Kappe

Beilstein J. Org. Chem. 2011, 7, 503–517, doi:10.3762/bjoc.7.59

• continuous flow processes is becoming increasingly important. In the past few years our research group [19][20][21][22][23][24][25] has reported a number of successful case studies where initial reaction optimization for a variety of synthetic transformations was performed under batch microwave conditions

• , followed by translation to high-temperature/high-pressure scalable continuous flow processes (“microwave-to-flow” paradigm) [26][27][28]. A recent example involves the synthesis of 5-substituted-1H-tetrazoles via an azide–nitrile cycloaddition pathway, using sodium azide (NaN3) as an inexpensive azide

Polyionic polymers – heterogeneous media for metal nanoparticles as catalyst in Suzuki–Miyaura and Heck–Mizoroki reactions under flow conditions

• Klaas Mennecke and
• Andreas Kirschning

Beilstein J. Org. Chem. 2009, 5, No. 21, doi:10.3762/bjoc.5.21

• DMF are employed and therefore leads to a minimum degree of leaching. The ease of preparation and the properties of polyionic catalyst 3 make it an attractive catalytic monolith for industrially relevant continuous flow processes particularly when employed in combination with a scavenger column for

• heterogenization of transition metals. A major hurdle for industrial applications of heterogenized homogeneous metal catalyst is associated with keeping metal leaching down to a minimum. Immobilization can be regarded as one enabling technique in organic chemistry [5][6] that in conjunction with continuous flow

• processes creates an ideal setup for an automated solution-phase synthesis. Furthermore, this combination of enabling techniques has great potential in the production of fine chemicals [7][8]. In continuation of our efforts in developing immobilization concepts for reagents and catalysts including

A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed- bed microreactor

• Andrew Bogdan and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2009, 5, No. 17, doi:10.3762/bjoc.5.17

• potential as continuous flow processes. Realizing this, we developed a catalytic packed-bed microreactor that could be used for the continuous flow oxidation of alcohols to aldehydes or ketones. Oxidations that do not require transition metal catalysts are particularly appealing since there is neither

Chemistry in flow systems

• Andreas Kirschning

Beilstein J. Org. Chem. 2009, 5, No. 15, doi:10.3762/bjoc.5.15

• focus on the development of flow devices for laboratory use and hence for industrial applications. An important field of research is the optimization and adaptation of known reactions and reaction sequences for use in flow systems. Advantageously, continuous-flow processes can be further improved by