Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• or crystals, or adsorbed on metallic substrates [9][10][11][12]. Conversion of the non-planar soluble precursor into the flat π-conjugated target compound is triggered on demand by a stimulus such as thermal activation, irradiation with light or injection of electrons, leading to the elimination of

Electrochemical vicinal oxyazidation of α-arylvinyl acetates

• Yi-Lun Li,
• Zhaojiang Shi,
• Tao Shen and
• Ke-Yin Ye

Beilstein J. Org. Chem. 2022, 18, 1026–1031, doi:10.3762/bjoc.18.103

• ][18][19][20][21][22] not only because it employs the passage of charge instead of chemical oxidants or reductants but also offers opportunities for the precise control of reactivity by "dialing-in" the specific potential on demand [23][24][25]. Specifically, the electrochemical oxyfunctionalization of

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

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

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides

• Mateo Berton,
• Kevin Sheehan,
• Andrea Adamo and
• D. Tyler McQuade

Beilstein J. Org. Chem. 2020, 16, 1343–1356, doi:10.3762/bjoc.16.115

• Grignards is reported. A low-cost pod-style synthesizer prototype, which incorporates single-use prepacked perfluorinated cartridges and bags of reagents for the automated on-demand lab-scale synthesis of carbon, nitrogen, and oxygen turbo magnesium bases is presented. This concept will provide access to

• fresh organomagnesium reagents on a discovery scale and will do so independent from the operator’s experience in flow and/or organometallic chemistry. Keywords: Knochel–Hauser base; lithium chloride; magnesium; on-demand; packed-bed reactors; plug and flow reactor; synthesizer; turbo Grignard reagent

• [5][6]; (3) new chemistry by conducting reactions outside of normal operating pressures and temperatures [7][8]; (4) new opportunities for the realization of automated chemistry, including on-demand systems [9][10][11][12]. We have recently focused on systems where solid-reagent cartridges are

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• applications related to Chemistry 4.0 standards. These were mainly photopolymer coatings, which can be found for applications in the graphic industry or to protect selected substrates. The huge release of heat on demand upon turning ON or OFF the NIR light source enables them for photothermal treatment in

• “molecular oven/furnace” in heat-based physical and/or chemical processes. There, they can generate heat in an ON/OFF procedure on demand [58]. Many examples of cyanines focus on the use of absorption in the NIR [64]. Among of the disclosed applications, photopolymerization depicts one representative method

• therapy named this phenomenon photothermal treatment [78][79][80] In addition, heat generation on demand also explains the function of laser drying developed for the graphic industry [11][12][13][14] or laser welding [21][22][23][24][25] where the release of heat by a photonic event responsibly patterns a

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

• Panagiotis S. Gritzapis,
• Panayiotis C. Varras,
• Nikolaos-Panagiotis Andreou,
• Katerina R. Katsani,
• Konstantinos Dafnopoulos,
• George Psomas,
• Zisis V. Peitsinis,
• Alexandros E. Koumbis and
• Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

• DNA-photocleavers, and are proposed as new leads for “on demand” biotechnological applications in drug discovery and medicine. Keywords: DNA binding; DNA photocleavage; N–O homolysis; oxime carbamates; photocleavage agents; Introduction Small organic molecules able to bind DNA provide promises for

• act as novel effective photobase generating DNA-photocleavers with predicted DNA photocleaving, able, as well, to be subjected to photoinduced sensitizing. Thus as a novel class of photocleavers, oxime carbamates may serve in the discovery of new leads for “on demand” biotechnological, technological

In search of visible-light photoresponsive peptide nucleic acids (PNAs) for reversible control of DNA hybridization

• Lei Zhang,
• Greta Linden and
• Olalla Vázquez

Beilstein J. Org. Chem. 2019, 15, 2500–2508, doi:10.3762/bjoc.15.243

• hybridization has demonstrated an enormous potential to regulate on-demand biological responses such as gene expression [1]. There are indeed a number of successful examples based on photocaged strategies [2][3][4][5], in which modified nucleic acids interfere irreversibly with gene expression in vitro [6][7

Azologization of serotonin 5-HT₃ receptor antagonists

• Karin Rustler,
• Galyna Maleeva,
• Piotr Bregestovski and
• Burkhard König

Beilstein J. Org. Chem. 2019, 15, 780–788, doi:10.3762/bjoc.15.74

• pharmacological response on demand [31][32][33]. To introduce photoresponsiveness into a biological system, different approaches are feasible, e.g., the use of caged ligands (CL) [34][35][36][37], photoswitchable tethered ligands (PTLs) [38][39][40], photoswitchable orthogonal remotely tethered ligands (PORTLs

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

• flow [2][3][4]. One use of such multiple step reactions is, for instance, the on-demand production of pharmaceuticals using compact, reconfigurable continuous flow systems [5]. The combination of flow chemistry with 3D-printed reactors is also a growing terrain in the last years [6][7][8][9][10][11][12

Cobalt–metalloid alloys for electrochemical oxidation of 5-hydroxymethylfurfural as an alternative anode reaction in lieu of oxygen evolution during water splitting

• Jonas Weidner,
• Stefan Barwe,
• Kirill Sliozberg,
• Stefan Piontek,
• Justus Masa,
• Ulf-Peter Apfel and
• Wolfgang Schuhmann

Beilstein J. Org. Chem. 2018, 14, 1436–1445, doi:10.3762/bjoc.14.121

• , which can be made accessible on demand [1]. Energy storage in hydrogen as a highly versatile energy carrier, which can be inexhaustibly obtained from water, is very appealing [2]. For the conversion of renewable energy into storable hydrogen, electrochemical water splitting turns out to be among the

A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

• Marcus Baumann,
• Ian R. Baxendale and
• Fabien Deplante

Beilstein J. Org. Chem. 2017, 13, 2549–2560, doi:10.3762/bjoc.13.251

• also deemed highly desirable to be able to produce material on demand using a flexible scale flow chemistry approach. Since the report of the first synthetic access to indoles by Fischer in 1835 more than a dozen further unique indole syntheses have been reported showcasing the importance of developing

• employed CDI cyclisation providing higher overall yields and improved quality product direct from the reactor. Indeed, the final product 8 was of sufficient purity for direct application allowing on demand and scalable production from a stable intermediate 12 in less than 2 h from reactor start-up

• , this created a convenient staging point to generate intermediate holding batches of material for subsequent on demand processing. Overall we envisage this laboratory scale design to offer several opportunities for further development enabling quick up regulation of production in the future

Synthesis of naturally-derived macromolecules through simplified electrochemically mediated ATRP

• Paweł Chmielarz,
• Tomasz Pacześniak,
• Katarzyna Rydel-Ciszek,
• Izabela Zaborniak,
• Paulina Biedka and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2017, 13, 2466–2472, doi:10.3762/bjoc.13.243

• polymerizations was well-controlled by applying optimal potential values during preparative electrolysis to prevent the possibility of intermolecular coupling of the growing polymer arms. This appears to be the first report using on-demand seATRP for the synthesis of QC-(PtBA-Br)5 pseudo-star polymers. The

• naturally-derived macromolecules showed narrow MWDs (Đ = 1.08–1.11). 1H NMR spectral results confirm the formation of quercetin-based polymers. These new flavonoid-based polymer materials may find applications as antifouling coatings and drug delivery systems. Keywords: flavonoids; on-demand seATRP

• ',5,6-pentahydroxyflavone-based core with 2-bromoisobutyryl bromide as initiation molecule, and grafting of the PtBA arms of the flavonoid-based moiety by facile seATRP technique. To demonstrate the possibility of temporal control, on-demand seATRP was carried out utilizing multiple-step potential

Automating multistep flow synthesis: approach and challenges in integrating chemistry, machines and logic

• Chinmay A. Shukla and
• Amol A. Kulkarni

Beilstein J. Org. Chem. 2017, 13, 960–987, doi:10.3762/bjoc.13.97

• speeding up the optimization, process development and actual translation of chemistry to products. This implies that integration of various core and peripheral domains from the relevant sciences and engineering is absolutely essential and unavoidable to automate on-demand and end-to-end synthesis of

Contribution of microreactor technology and flow chemistry to the development of green and sustainable synthesis

• Flavio Fanelli,
• Giovanna Parisi,
• Leonardo Degennaro and
• Renzo Luisi

Beilstein J. Org. Chem. 2017, 13, 520–542, doi:10.3762/bjoc.13.51

• hydrochloride. Remarkably, for future applications of the platform, the produced medicines also met the U.S. Pharmacopeia standards. The future use of this kind of platform would concern the “on-demand” production or the “instantaneous” production of short-lived pharmaceuticals (Figure 4). Other advantageous

The synthesis of functionalized bridged polycycles via C–H bond insertion

• Jiun-Le Shih,
• Po-An Chen and
• Jeremy A. May

Beilstein J. Org. Chem. 2016, 12, 985–999, doi:10.3762/bjoc.12.97

• catalyst control for these reactions should be pursued. Ideally, the catalyst would dictate the diastereoselectivity, the enantioselectivity, and the location of C–H bond insertion to provide any of the possible product isomers selectively on demand. Bridged polycyclic natural products. Strategic

Enabling technologies and green processes in cyclodextrin chemistry

• Giancarlo Cravotto,
• Marina Caporaso,
• Laszlo Jicsinszky and
• Katia Martina

Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30

• miniaturized continuous flow reactor, also called microreactor, offers many advantages over conventional scale reactors, including considerable improved energy exploitation, increased reaction speed and yield, safety, reliability, scalability, on-site/on-demand production, etc., and a much finer degree of

Effective immobilisation of a metathesis catalyst bearing an ammonium-tagged NHC ligand on various solid supports

• Krzysztof Skowerski,
• Jacek Białecki,
• Stefan J. Czarnocki,
• Karolina Żukowska and
• Karol Grela

Beilstein J. Org. Chem. 2016, 12, 5–15, doi:10.3762/bjoc.12.2

• still of interest. It brings some additional possibilities to be explored, such as on-demand catalyst removal and insertion controlled by a magnetic field. If it is required, complex 8 can then easily be recovered from the support by simply washing the heterogeneous material 8-Fe with a polar solvent

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• combination of biological systems for centralised hydrogen storage through CO2 reduction as formate, with cheap zeolite catalysts for decentralised on demand hydrogen regeneration appears a very promising sustainable approach toward a hydrogen economy (Figure 6). In vitro production of CO with CODH Reduction

• mediated application of solar energy for the fixation of CO2. Finally, electrons can be stored within chemical species that may then be oxidised by organisms to regenerate the electrons on-demand [20]. Hydrogen and formic acid appear most suited for such applications, due to their chemical properties, and

Convenient preparation of high molecular weight poly(dimethylsiloxane) using thermally latent NHC-catalysis: a structure-activity correlation

• Stefan Naumann,
• Johannes Klein,
• Dongren Wang and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2015, 11, 2261–2266, doi:10.3762/bjoc.11.246

• in situ from thermally labile CO2 adducts. This type of NHC delivery offers the double advantage of improved stability and storability of the NHC adduct and the possibility to generate “on demand” polymerization systems where the catalyst can be activated by heating. This way, a latent, easy-to

• thermally labile pre-catalysts both practically feasible and advantageous. Conclusion In conclusion, we have demonstrated the first polymerization of D4 using NHC-carboxylates. Sterically non-hindered, highly nucleophilic protected NHCs like 5Me-Me-CO2 offer access to an “on demand”, metal-free and

Asymmetric 1,4-bis(ethynyl)bicyclo[2.2.2]octane rotators via monocarbinol functionalization. Ready access to polyrotors

• Cyprien Lemouchi and
• Patrick Batail

Beilstein J. Org. Chem. 2015, 11, 1881–1885, doi:10.3762/bjoc.11.202

• dirotors in higher yield than our former [10][12] synthesis of 6 and with very diverse functional groups (Scheme 2). Hence, large quantities of the diyne diester dirotor, 9 are obtained (Scheme 2) providing ready, on-demand access to 10. The dirotors 3, 6 and 9 are synthesized by palladium-catalyzed

Ruthenium indenylidene “1^st generation” olefin metathesis catalysts containing triisopropyl phosphite

• Stefano Guidone,
• Fady Nahra,
• Alexandra M. Z. Slawin and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2015, 11, 1520–1527, doi:10.3762/bjoc.11.166

• polymerization on demand through use of a stimulus [35][36]. The use of this catalyst in the ring-closing metathesis (RCM) reaction gave excellent conversions of challenging substrates, even at low catalyst loadings. The high activity and robustness of cis-Caz-1 is derived from synergistic effects between the σ

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

• reactor. This enables the quick and easy relocation of manufacturing to permit medications to be made bespoke at the site of requirement or in future applications on demand as required by the patient or prescriber. It is also worth highlighting here two European initiatives in this regrad, namely CoPIRIDE

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• affinity towards PA-IL lectins on demand, we were intrigued in the ability of our light-responsive systems to work when immobilized on a surface. To this end we attached the photoswitchable precision glycooligomers directly to the SPR chip and performed a second set of lectin binding experiments using SPR

Flow microreactor synthesis in organo-fluorine chemistry

• Hideki Amii,
• Aiichiro Nagaki and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2013, 9, 2793–2802, doi:10.3762/bjoc.9.314

• , [18F]FDG is radiopharmaceutically used for positron emission tomography (PET). However, due to the short radioactivity elimination half-life of [18F] (t1/2 = 110 min), protocols for rapid and selective synthesis of [18F]-labeled compounds have been required. In addition, on-site and on-demand chemical