Ex-situ generation of gaseous nitriles in two-chamber glassware for facile haloacetimidate synthesis

• Nikolai B. Akselvoll,
• Jonas T. Larsen and
• Christian M. Pedersen

Beilstein J. Org. Chem. 2025, 21, 2465–2469, doi:10.3762/bjoc.21.188

• their subsequent reaction with O-nucleophiles in the second chamber. The method is easy to setup, control and gives access to new haloacetimidates under mild conditions, similar to the ones used for the synthesis of the more commonly used trichloroacetimidates. Keywords: gaseous reagents; glycosyl

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

• intensification. The implicit high pressure self-contained environment created by a pumped flow system allows for superior reaction kinetics often achieved by elevating the working temperature of the system. This capability also opens up the opportunity for the integration of volatile and gaseous reagents into

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

• material [55][56][57]. Flow chemistry also enables chemists to safely use hazardous gaseous reagents that are otherwise avoided, whilst simultaneously increasing the gas/liquid–gas/solid interfacial surface area which enhances reactivity [58][59][60][61]. This was highlighted by Noël and co-workers, who

• aromatic heterocycle substrates within 8–20 min, transformations that would require days in batch protocols (Scheme 1) [62]. Flow systems can be pressurised easily with back pressure regulators, enhancing the solubility of gaseous reagents in the reaction solvents [36][63]. Flow processes are also commonly

Synthesis of acylglycerol derivatives by mechanochemistry

• Karen J. Ardila-Fierro,
• Andrij Pich,
• Marc Spehr,
• José G. Hernández and
• Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

• mechanochemical synthesis of Cu–carbene complexes from N,N-diarylimidazolium salts, dioxygen and metallic copper [40], which involved a mechanochemical reaction with gaseous reagents [41]. Pleasingly, this time the reaction afforded product 4a, although the yield remained low (59%), even after three hours of

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

A flow reactor setup for photochemistry of biphasic gas/liquid reactions

• Josef Schachtner,
• Patrick Bayer and
• Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2016, 12, 1798–1811, doi:10.3762/bjoc.12.170

• ], multiphasic reactions including solid-phase protocols [18], addition of gaseous reagents [19], high-pressure conditions [20], cascade conversions without intermediate work-up operations [21], as well as thin film, falling film [22], micro-channel [23], and tube-in-tube reactors [24][25] for reactions between

• possibly additives, the gas phase, containing the gaseous reagents, and the light (Figure 1). Only very few microreactor setups for such “quasi tri-phasic” processes have been reported [33][34]; most of them are film/falling film [22], microchannel [23][35] or simple tube reactors [35][36][37]. The reactor

• valve causes pressure spikes which prohibits a steady volume stream through the mass flow controller. Mass flow controller The mass flow controller fulfills an identical role as its liquid phase complement, the pulsation-free pump. The precise control of the mass flow of the gaseous reagents (here

The synthesis of active pharmaceutical ingredients (APIs) using continuous flow chemistry

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2015, 11, 1194–1219, doi:10.3762/bjoc.11.134

• protocol completed the synthesis of vildagliptine (77). Again, it was highlighted that the control of the exothermic Vilsmeier reagent formation and subsequent handling of this toxic and unstable intermediate was ideally suited to a continuous production and consumption in flow protocol. Gaseous reagents

• allowing safe and efficient use of gaseous reagents as well as more effective ways of quickly transitioning between very low and very high temperatures that are key for streamlining modern flow synthesis routes. Although the widely used H-Cube system had provided a popular solution for safe and convenient

• hydrogenation reactions at lab scale [76][77][78][79], the safe utilisation of other gaseous reagents at above ambient pressure was a relatively neglected area in flow chemistry for a long time. Only a few examples of flow hydrogenations and carbonylations had been reported [80][81][82][83]. The redevelopment

Pd/C-catalyzed aerobic oxidative esterification of alcohols and aldehydes: a highly efficient microwave-assisted green protocol

• Marina Caporaso,
• Giancarlo Cravotto,
• Spyros Georgakopoulos,
• George Heropoulos,
• Katia Martina and
• Silvia Tagliapietra

Beilstein J. Org. Chem. 2014, 10, 1454–1461, doi:10.3762/bjoc.10.149

• versatility of these reactors in promoting reactions with gaseous reagents in a closed cavity [56]. In this present work, we report an efficient Pd/C-catalyzed aerobic oxidative esterification of aldehydes and alcohols in the presence of molecular oxygen in a closed MW reactor. The optimized procedure does

One-pot sequential synthesis of isocyanates and urea derivatives via a microwave-assisted Staudinger–aza-Wittig reaction

• Diego Carnaroglio,
• Katia Martina,
• Giovanni Palmisano,
• Andrea Penoni,
• Claudia Domini and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2013, 9, 2378–2386, doi:10.3762/bjoc.9.274

• established as a reliable technique which can be applied on a range of scales [26]. Despite MW irradiation being commonly used in organic synthesis, only few publications describe this technique with gaseous reagents in closed vessels and in heterogeneous gas-phase reactions that are important for industrial

• results have been obtained under MW irradiation in a closed vessel also with gaseous reagents. The optimized procedure benefited from the use of a quasi-stoichiometric amount of PS-PPh2 and can be applied for the efficient, safe, rapid, and cost-effective production of urea derivative libraries

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

• presence of oxygen in the solvent stream. With increased concentrations of oxygen in the reactor atmosphere, this oxidation proceeded with faster rates (Figure 18b). Having determined that the gaseous reagents were passing through the semipermeable tubing, we were able to use the tube-in-tube reactor for