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Search for "efficiency" in Full Text gives 1209 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Recent advances in organocatalytic atroposelective reactions

  • Henrich Szabados and
  • Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

Graphical Abstract
  • (Scheme 61) [91]. After testing a considerable number of substrates, the authors achieved excellent yields and enantioselectivities. The synthetic utility of this approach stems from being able to skip additional reaction steps and thus omit reagents used in those steps, leading to increased efficiency
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Published 09 Jan 2025

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

  • Pablo Quijano Velasco,
  • Kedar Hippalgaonkar and
  • Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

Graphical Abstract
  • selection, a dispensing module for solids and liquids, a reaction module capable of heating and stirring, a sample preparation module, and a LC–MS characterization module (Figure 2d). The efficiency of the system has been demonstrated in three reactions types, namely Suzuki–Miyaura coupling, Buchwald
  • –Hartwig amination, and Ullmann coupling. These experiments showcased a conversion rate that outperformed existing reference systems and provided at least six times the efficiency in the experimentation, besides synthesis planning, optimization, and downstream workup tasks. The throughput of SynBot is
  • , differing from established isolation and separation techniques, holds the promise of not only enhancing the efficiency of HTE flow synthesis but also paving the way for more sustainable growth in this research area. Autonomous self-optimizing flow reactors Autonomous self-optimizing flow reactors (ASFRs
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Published 06 Jan 2025

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

  • Shuxian Qiu,
  • Duan Dong,
  • Jiahui Li,
  • Huiting Wen,
  • Jinpeng Li,
  • Yu Yang,
  • Shengxian Zhai and
  • Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

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  • electrochemical studies, showing that the photophysical properties of PhFlOP depend on the nature of the electron-donating groups [31]. Later, Wu and co-workers introduced various electron donors to the PhFlOP unit to form new TADF emitters with high electroluminescence efficiency [32][33]. Despite this progress
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Published 30 Dec 2024

Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

  • Beatriz Dedeiras,
  • Catarina S. Caldeira,
  • José C. Cunha,
  • Clara S. B. Gomes and
  • M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

Graphical Abstract
  • formed by carboxylic acids, enhancing its versatility and effectiveness in drug design [27]. Traditional sulfonamide preparation involves combining sulfonyl chlorides and amines [25][28][29]. Despite the efficiency of traditional methods, challenges still remain, e.g., use of harsh conditions, like
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Published 19 Dec 2024

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

  • Thierry Milcent,
  • Pascal Retailleau,
  • Benoit Crousse and
  • Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

Graphical Abstract
  • dehydropiperazic acid to act as β or γ-turn is excluded. Interestingly, this novel scaffold rather promotes extended structures. Conclusion To conclude, we have developed a new methodology to synthesize β-analogs of dehydropiperazic acid incorporating fluorinated groups. In order to improve the efficiency of this
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Published 04 Dec 2024

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

  • Lucía Campos-Prieto,
  • Aitor García-Rey,
  • Eddy Sotelo and
  • Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

Graphical Abstract
  • three or more reagents are combined in one step to yield a single product that contains most of the atoms from the starting materials [1][2]. Among the advantages of MCRs are their high atom economy and efficiency in bond formation, along with the cost-effectiveness of separating and purifying products
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Published 03 Dec 2024

Hypervalent iodine-mediated intramolecular alkene halocyclisation

  • Charu Bansal,
  • Oliver Ruggles,
  • Albert C. Rowett and
  • Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

Graphical Abstract
  • , Xu, Zhang, Zhu and co-workers reported a method to catalytically synthesise 5‑fluoro-2-aryloxazolines 39 by utilising BF3·Et2O as the fluoride source and activating reagent (Scheme 21) [6]. The synthesis of these derivatives was achieved with high efficiency, resulting in good to excellent yields of
  • reaction of 2-alkenylanilines 65 with PIDA and LiBr resulted in the successful synthesis of various 3-bromoindoles 66 in high yields obtained under the optimised reaction conditions, highlighting the efficiency of the synthetic protocol. The proposed mechanism suggests that the reactive AcO–Br species is
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Published 28 Nov 2024

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

  • Cesia M. Aguilar-Morales,
  • América A. Frías-López,
  • Nadia V. Emilio-Velázquez,
  • Alejandro Islas-Jácome,
  • Angelica Judith Granados-López,
  • Jorge Gustavo Araujo-Huitrado,
  • Yamilé López-Hernández,
  • Hiram Hernández-López,
  • Luis Chacón-García,
  • Jesús Adrián López and
  • Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

Graphical Abstract
  • efficiency and creating six new bonds (two C–C, three C–N, and one N–N). Additionally, the products were evaluated against breast cancer MCF-7 cells, finding moderate activity in the compounds substituted with fluorine and chlorine. Keywords: 1,5-disubstituted tetrazoles; high-order multicomponent reaction
  • -disubstituted tetrazole-methanesulfonylindole derivatives, with yields ranging from 16% to 55% after purification by column chromatography. Despite some yields being modest, they are deemed reasonable considering the reaction’s structural complexity, atom economy, and the efficiency achieved in terms of time
  • . Significantly, this protocol enables the rapid and straightforward synthesis of highly 2-substituted indoles with high bond-forming efficiency, creating six new bonds (two C–C, three C–N, and one N–N). Our synthetic strategy would represent the second report in which the Pd/Cu-catalyzed heteroannulation
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Published 26 Nov 2024

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

  • Robin Schulte,
  • Dustin Schade,
  • Thomas Paululat,
  • Till J. B. Zähringer,
  • Christoph Kerzig and
  • Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

Graphical Abstract
  • ). Indeed, the quenching efficiency of triplet-excited [Ru(phen)3](PF6)2 by 1i was calculated to be as low as 5% under the highly diluted conditions required for the experiments in Figure 3. In order to gain structural information about the photoproducts, the photoisomerization reactions were also examined
  • be investigated in the presence of the photosensitizer because these substrates have no sufficient solubility in acetonitrile. To assess the efficiency of the photoreactions, photoisomerization quantum yields were determined in cyclohexane by actinometry (λex = 310 nm or 340 nm) [41][42]. The quantum
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Published 21 Nov 2024

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

  • Anastasia I. Ershova,
  • Sergey V. Fedoseev,
  • Konstantin V. Lipin,
  • Mikhail Yu. Ievlev,
  • Oleg E. Nasakin and
  • Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

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  • flexibility, high efficiency, and versatility, making them essential for modern high-tech applications. Despite the wide variety of known push–pull molecules, the number of fluorescent cores with synthetic potential for tuning the emission wavelength to achieve a full-emission spectrum is limited. Typically
  • rigidity along the C–C bond between the heterocycle and ethene bridge due to the fused cyclic fragment. As a consequence of the additional ring, the fluorescence efficiency increased. At the same time, solid-state emission was observed due to the steric hindrance, which prevented intermolecular
  • highest fluorescence efficiency of 53.4% was observed for the para-methyl derivative 1b. Solutions of stilbazoles 1 in DMSO were also characterized by large Stokes shift values, reaching 207 nm (5846 cm−1) and showing nonradiative loss of excitation energy. It should be noted that stilbazoles 1, in
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Published 19 Nov 2024

Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins

  • Mike Brockmann,
  • Jonas Lobbel,
  • Lara Unterriker and
  • Rainer Herges

Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248

Graphical Abstract
  • transfer and increases the efficiency [12]. Three conditions should be met for the target porphyrins of this study. 1. The acid covalently bound to the porphyrin should have an acid strength similar to trifluoroacetic acid. 2. The length of the tether with which the acid group is bound should be sufficient
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Published 15 Nov 2024

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

  • Sondos A. J. Almahmoud,
  • Joseph Cameron,
  • Dylan Wilkinson,
  • Michele Cariello,
  • Claire Wilson,
  • Alan A. Wiles,
  • Peter J. Skabara and
  • Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

Graphical Abstract
  • × 10−4 cm2 V−1 s−1) and 2-ethylhexyl chains (4.93 × 10−5 cm2 V−1 s−1). The stronger π–π interactions led to a higher power conversion efficiency (PCE) as a result of the higher short-circuit current density (Jsc), due to films with higher crystallinity providing a smoother pathway to charge carriers to
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Published 13 Nov 2024

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

  • Ritu Mamgain,
  • Kokila Sakthivel and
  • Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

Graphical Abstract
  • , diaryliodonium salts (DAIS), a versatile category of hypervalent iodine compounds, have seen significant progress in hypervalent iodine chemistry. Their efficiency and environmentally friendly characteristics have positioned DAIS as next-generation arylation reagents [29][30]. Other than aromatic electrophiles
  • efficiency and effectiveness as a synthetic approach. Furthermore, a transition-metal-free arylation of quinoxalines 17 and quinoxalinones 19 via aryl radicals was discussed by Li and co-workers in 2022. In this report the aryl radicals were generated by planetary ball milling of diaryliodonium salts 16 at a
  • . Notably, the efficiency of the cross-coupling reaction was observed to increase with the transfer of electron-poor aryl groups from the hypervalent iodine salt. Thus, electron-withdrawing substituents such as trifluoromethyl, m-chloro, and fluorine on the aryl group promoted efficient coupling. Moreover
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Published 13 Nov 2024

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

  • Marzieh Norouzi,
  • Mohammad Taghi Nazeri,
  • Ahmad Shaabani and
  • Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

Graphical Abstract
  • achieve this goal [7][33]. Among them, isocyanide-based multicomponent reactions (I-MCRs) are one of the well-known strategies in this field due to their operational simplicity, one-pot, convergent properties and atom economy, high efficiency, and high levels of chemical selectivity [34][35][36]. In
  • increase and the electron-donating substituents led to a decrease in the reaction efficiency (Scheme 3, 4a–k). In addition, benzothiazepine was used in this protocol and the corresponding pyrrole-fused benzothiazepine was obtained with a yield of 73% (Scheme 3, 4l). Also, various isocyanides were suitable
  • benzoxazepine, the presence of an electron-withdrawing group leads to an increase in the yield of pyrrole-fused triazolobenzodiazepines whereas electron-donating groups led to a decrease in its yield. Also, the substitution of naphthyl used in gem-diactivated olefins increased the efficiency of the desired
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Published 11 Nov 2024

Multicomponent synthesis of α-branched amines using organozinc reagents generated from alkyl bromides

  • Baptiste Leroux,
  • Alexis Beaufils,
  • Federico Banchini,
  • Olivier Jackowski,
  • Alejandro Perez-Luna,
  • Fabrice Chemla,
  • Marc Presset and
  • Erwan Le Gall

Beilstein J. Org. Chem. 2024, 20, 2834–2839, doi:10.3762/bjoc.20.239

Graphical Abstract
  • stoichiometric amount of LiCl was essential for the efficiency of the subsequent three-component coupling with aldehydes and amines. A variety of primary, secondary, and tertiary organozinc reagents as well as secondary amines and aromatic aldehydes could be used for the straightforward preparation of α-branched
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Published 07 Nov 2024

Mechanochemical difluoromethylations of ketones

  • Jinbo Ke,
  • Pit van Bonn and
  • Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

Graphical Abstract
  • efficiently converted to the target products under solvent-free conditions. The reactions proceed at room temperature and are complete within 90 minutes, demonstrating both efficiency and experimental simplicity. Keywords: ball milling; difluorocarbene; difluoromethylations; difluoromethyl enol ether
  • reaction conditions with difluorocarbene precursor 2, KFHF (4 equiv) as activator, and CsCl or KCl (4 equiv) as grinding auxiliaries in a PTFE milling jar for 90 min at 25 Hz (Scheme 3). To get an initial efficiency estimate, the crude reaction mixtures were first analyzed by quantitative 1H NMR
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Published 04 Nov 2024

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

  • Yuta Kabumoto,
  • Eiichiro Yoshimoto,
  • Bing Xiaohuan,
  • Masato Morita,
  • Motohiro Yasui,
  • Shigeyuki Yamada and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

Graphical Abstract
  • high enantiomeric excess (90% ee for (S)-23d and (S)-23e). Furthermore, it was found that the substituent position on the aromatic ring did not significantly influence the reaction efficiency as well as optical purity and the reaction proceeded in a highly enantioselective manner (91% ee for (S)-23f
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Published 01 Nov 2024

Copper-catalyzed yne-allylic substitutions: concept and recent developments

  • Shuang Yang and
  • Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

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  • precise and highly regioselective construction of an array of novel chiral coumarin derivatives, characterized by their exceptional synthetic efficiency and remarkable tolerance towards a broad spectrum of functional groups (Scheme 21, 22a–n). Almost at the same time, Lin et al. [71] also devised a copper
  • , followed by a Conia-ene cyclization. The absolute configuration of the products is controlled by the ligand, which further confirms the remote stereocontrol of the copper catalyst. They obtained a single crystal of dinuclear copper and confirmed that the catalytic efficiency of the single crystal is
  • , resulting in the C2-dearomatized naphthalenone products 41a–d with high efficiency (Scheme 41). In addition, electron-rich phenols or nonfunctionalized 2-naphthols could also be used as nucleophiles, providing the desired chiral spirocycles 43a–e and 44a–e in good yields with excellent ee values (Scheme 42
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Published 31 Oct 2024

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

  • Francesco Gambuti,
  • Jacopo Pizzorno,
  • Chiara Lambruschini,
  • Renata Riva and
  • Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

Graphical Abstract
  • detrimental (Table 2, entries 4, 5 and 7), while higher temperature improved the efficiency of the process (Table 2, entry 6). Under the optimized conditions we were able to obtain 3a with a 61% isolated yield, which can be considered an excellent result, as it is related to a four-step process (an average
  • overall yield resulted even better (76% starting from 1 g of N-Ph-THIQ), a slight decrease of the conversion of α-aminoamidine 2d into the spiro[indole-THIQ] 3d was observed. As expected, the use of a larger-diameter reactor caused a low penetration of the irradiation, thus leading to lower efficiency
  • the preparation of complex structures without using catalysts, and purification of intermediates. Remarkably, the reaction can be performed even on gram scale without loss of efficiency. Studies directed toward evaluating the biological activities of the spiroindolenines are currently underway in our
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Published 29 Oct 2024

Photoluminescence color-tuning with polymer-dispersed fluorescent films containing two fluorinated diphenylacetylene-type fluorophores

  • Kazuki Kobayashi,
  • Shigeyuki Yamada,
  • Motohiro Yasui and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2682–2690, doi:10.3762/bjoc.20.225

Graphical Abstract
  • absorption spectrum of 1a in the two-component film. This result also clearly suggests an energy transfer from 1a to 1c. The fluorescence resonance energy transfer efficiency (EFRET) [30][31] was calculated from the ratio of the fluorescence lifetimes of the two- and high-energy-component films (Equation 1
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Published 23 Oct 2024

Computational design for enantioselective CO2 capture: asymmetric frustrated Lewis pairs in epoxide transformations

  • Maxime Ferrer,
  • Iñigo Iribarren,
  • Tim Renningholtz,
  • Ibon Alkorta and
  • Cristina Trujillo

Beilstein J. Org. Chem. 2024, 20, 2668–2681, doi:10.3762/bjoc.20.224

Graphical Abstract
  • catalyst efficiency and selectivity in sustainable chemistry applications. Keywords: asymmetric catalysis; carbon dioxide; CO2; epoxide; frustrated Lewis pairs (FLPs); volcano plot; Introduction The field of frustrated Lewis pairs (FLPs) has flourished since their seminal discovery in 2006 by Stephan and
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Published 22 Oct 2024

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

  • Alfiya R. Gimadieva,
  • Yuliya Z. Khazimullina,
  • Aigiza A. Gilimkhanova and
  • Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

Graphical Abstract
  • convenience of the process, our objective is to enhance the efficiency of the Elbs and Boyland–Sims peroxydisulfate oxidation reactions. Results and Discussion We conducted research to enhance the product yield of peroxydisulfate oxidation reactions of specific nitrogen-containing heterocyclic compounds, such
  • generate sulfate anion radicals (SO4•−) [42] during their interaction with sulfate anions. This reaction occurs at a significant rate (k = 3.1∙108 min−1) [43] and leads to the recombination of peroxydisulfate in the reaction mixture. It has been demonstrated that the efficiency of peroxydisulfate
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Published 16 Oct 2024

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

  • Yohei Haketa,
  • Takuma Matsuda and
  • Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

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  • introduction of N-aryl units during the synthesis is rendered difficult owing to steric hindrances. For example, N-phenyl-substituted TATA+ cation 1b+ (Figure 1) [26] exhibited slightly red-shifted absorption and emission, with a higher quantum efficiency compared to those of N-alkyl-substituted TATA+ cations
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Published 10 Oct 2024

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

  • Nian Li,
  • Ruzal Sitdikov,
  • Ajit Prabhakar Kale,
  • Joost Steverlynck,
  • Bo Li and
  • Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

Graphical Abstract
  • oxidation then yields the intermediate. Subsequent desilylation and substrate/product exchange complete the catalytic cycle (Scheme 40). This approach underlines the potential of asymmetric electrosynthesis in achieving high selectivity and efficiency in complex molecule synthesis, further broadening the
  • efficient method for C–H functionalization. The continuous flow setup allows for precise control over reaction conditions, enhanced mass transfer, and improved reaction kinetics, leading to higher efficiency and faster reaction times. In 2023, the Chiang group reported the photoelectrochemical homo-coupling
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Published 09 Oct 2024

Visible-light-mediated flow protocol for Achmatowicz rearrangement

  • Joachyutharayalu Oja,
  • Sanjeev Kumar and
  • Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

Graphical Abstract
  • dihydropyranones due to its ability to better control of reaction conditions, including more uniform light exposure and improved mixing efficiency, which result in higher reaction rates and more consistent product quality. Additionally, the flow system enhances mass transfer and reduces reaction times, leading to
  • developed by Guan-Ben Du et al. [14]. Very often, the photolysis reactions performed in batch process encounter issues that include ineffective illumination, improper mixing, prolonged reaction durations, low quantum efficiency and mass transfer, a limited surface-to-volume ratio, along with an inadequate
  • transformations, then reaction extraction and separation, into a single process, which are typically performed individually/separately in batch methods. This enhances the overall efficiency for obtaining the desired product(s) from the reaction mixture. In continuation to our efforts on developing flow-based
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Published 08 Oct 2024
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