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

• converted energy [3][4][5][6][7][8]. This drawback may be solved with the progress in battery technology, however, the use of high-performance batteries still requires some problematic materials, which are difficult to access, hardly recyclable, or which may harm the environment [9]. Thus, in the present

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

• Anthony J. Burke and
• Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

• , a diverse selection of contributions from a cross section of these participants is presented. The variety of material from different fields showcased in this thematic issue truly reflects the range and breath of this conference. In the contribution by Dargó et al. [11], “A novel recyclable

Electrochemical allylations in a deep eutectic solvent

• Sophia Taylor and
• Scott T. Handy

Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189

• application of simple, inexpensive, and recyclable deep eutectic solvents to the allylation of carbonyls. While several sets of conditions were developed, the goal of avoiding stoichiometric amounts of metal has proven elusive. Still, a deep eutectic solvent can be used to plate out and thus recover the metal

• limitation by using electrochemistry with catalytic amounts of metal or perhaps by recovering and recycling the metal with a recyclable solvent was the goal motivating this project. With this as a background, we undertook an investigation of electrochemical allylation in DES. Results and Discussion While

Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• . Heterogeneous catalysts are easy to handle and can be easily separated from the reaction mixture by filtration, centrifugation or magnetic force, thus allowing catalysts to be recycled multiple times. Most highly stable and recyclable catalysts are attached to solid supports [11]. Solid supports are generally

• supported organocatalyst whose catalytic efficiency can be reproduced over a sufficient number of reaction cycles. Despite the difficulty of the challenge, the design of heterogeneous, recyclable organocatalytic systems is of high interest [8]. The continued development of efficient catalytic recovery

• 39% ee for a pore size of 11.3 nm [64]. Catalyst supports must meet certain criteria, including being chemically inert, and the supported catalyst should exhibit high stability across various reaction conditions while also being easily recyclable [8][64]. When the solid support is not inert, it can

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• KSF clays as recyclable and heterogeneous catalysts to catalyze the Cannizzaro reaction by 1,4-diazabicyclo[2.2.2]octane under microwave irradiation and solvent-free conditions giving the products in excellent yields within seconds. The solid clay applied in the first cycle can be recovered and reused

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

• introduced nano n-propylsulfonated γ-Fe2O3 (NPS-γ-Fe2O3), which constitutes a magnetically recyclable heterogeneous catalyst that works in the exact same manner as HPA/TPI-Fe3O4 [103]. Some small differences between the two methods were the ability of ketones to form the respective BIMs, when NPS-γ-Fe2O3 was

• various oxidation and hydrogenation reactions [105]. NanoAg-Pt doped silicate constitutes an efficient and recyclable catalyst that can be reused without a notable loss in catalytic activity (Scheme 17). Wanting to avoid the use of conventional heating, Karthikeyan and his co-workers turned to microwave

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• recycling of the organocatalysts can be achieved in a simple step by centrifugation or filtration. Previously, we have demonstrated the homogeneous and heterogeneous recycling of cinchona-based organocatalysts [20][25][26][29]. Continuing our work, we aimed to synthesize a novel, recyclable lipophilic

• this catalyst easily by incorporating a lipophilic unit, which leads to a drastic increase (5.78 to 28.8) in the logP value of the organocatalyst 2. The recyclable organocatalyst can be divided into three units: the catalytic unit, the linker, and the lipophilic tag with octadecyl chains (Figure 1

• literature [41]. Application of cinchona squaramide 1 and recyclable, lipophilic cinchona squaramide organocatalysts 2 in a new, gram-scale stereoselective synthesis of baclofen precursor. Classification of the tested non-polar solvents according to the GSK’s solvent sustainability guide [34]. Recycling of

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• ) [70]. We expected that using olefinic oxindoles 14 as alkenes for the [3 + 2] cycloaddition could afford spirooxindole-pyrrolizidines. The method development revealed that recyclable zeolite HY acid is a good catalyst for the cycloaddition [70]. Thus, the zeolite HY-catalyzed reaction of glycine with

Selective construction of dispiro[indoline-3,2'-quinoline-3',3''-indoline] and dispiro[indoline-3,2'-pyrrole-3',3''-indoline] via three-component reaction

• Ziying Xiao,
• Fengshun Xu,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1234–1242, doi:10.3762/bjoc.19.91

• multicomponent reactions have been successfully developed to construct multifunctionalized or polycyclic spirooxindoles. For example, Zhang successfully developed a recyclable bifunctional cinchona/thiourea-catalyzed four-component Michael/Mannich cyclization sequence for the asymmetric synthesis of

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• artificial photosynthesis. Systems for photocatalytic carbon dioxide reduction are optimized using sacrificial electron donors. One strategy for coupling carbon dioxide reduction and water oxidation to achieve artificial photosynthesis is to use a redox mediator, or recyclable electron donor. This review

• decoupled water splitting research, are introduced as alternative recyclable sacrificial electron donors and their oxidation potentials are compared to the redox potentials of some model photosensitizers. The aim of this review is to act as a reference for researchers developing photocatalytic systems with

• sacrificial electron donors, and for researchers interested in designing new redox mediator and recyclable electron donor species. Keywords: artificial photosynthesis; photocatalysis; redox couple; sacrificial electron donor; solar fuels; Introduction Artificial photosynthesis research has resulted in the

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• 2013, Zhang and co-workers [67] reported the preparation of a new recyclable magnetic nanoparticle-supported antimony catalyst (γ-Fe2O3@SiO2-Sb-IL) and its application in the filtration-free, Clauson–Kaas synthesis of N-substituted pyrroles. This catalyst is fairly easy to make, air stable, and

• of reaction. Mahmoudi and Jafari [85] reported the preparation of a new on magnetic nanoparticles sulfonic acid-supported catalyst with maghemite coating as a magnetically recyclable catalyst Fe3O4@-γ-Fe2O3-SO3H. This heterogeneous catalyst is used for the synthesis of N-substituted pyrrole

One-pot double annulations to confer diastereoselective spirooxindolepyrrolothiazoles

• Juan Lu,
• Bin Yao,
• Desheng Zhan,
• Zhuo Sun,
• Yun Ji and
• Xiaofeng Zhang

Beilstein J. Org. Chem. 2022, 18, 1607–1616, doi:10.3762/bjoc.18.171

• one-pot reactions with recyclable organocatalysts [69]. Notably, we conferred K10 acid to promote the C–H activation in the synthesis of spirooxindolepyrrolidines, and used Zeolite HY catalyst to synthesize diastereoselective dispiro[oxindolepyrrolidine]s with a butterfly shape (Scheme 1A and 1B) [70

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

• Wei-Hsin Hsu,
• Susanne Reischauer,
• Peter H. Seeberger,
• Bartholomäus Pieber and
• Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

• light-mediated carbon–heteroatom cross-couplings of sodium sulfinates, carboxylic acids and sulphonamides with aryl halides (Figure 2) [28]. Although recyclable, batch reactions are characterized by long reaction times (24 h). Here, we present a detailed investigation of a continuous-flow strategy for

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• , recyclable, and selective for the coupling between aryl halides and phenylacetylene in PEG as the solvent (Scheme 22). The effect of various reaction parameters such as solvent, base, temperature, and catalyst loading was assessed by the model reaction between bromobenzene and phenylacetylene. Optimization

• recyclable bimetallic magnetic particles called Fe3O4@PEG/Cu-Co, was found to be effective in catalyzing the Sonogashira coupling of aryl halides and phenylacetylene in water as the solvent (Scheme 32) [44]. Aryl halides containing functional groups such as amino, hydroxy, carboxy or formyl, were found

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• , India Department of Chemistry, Presidency University, Kolkata-700073, India Department of Chemistry, R. K. Mission Residential College, Narendrapur, Kolkata-700103, India 10.3762/bjoc.18.14 Abstract A heterogeneous and magnetically recyclable Ni–chitosan nanocatalyst was synthesized and thoroughly

• yield, the use of an eco-friendly solvent and a recyclable nanocatalyst, as well as reaction at room temperature. Keywords: 1,4-DHPs; green synthesis; magnetically recyclable catalyst; Ni–chitosan nanoparticles; ultrasonication; Introduction Homogeneous catalysts, despite having an outstanding

• , we synthesized a Ni–chitosan complex and exploited the coordination properties of the complex to use it as an effective and recyclable catalyst towards the green synthesis of C5–C6-unsubstituted 1,4-dihydropyridine (1,4-DHP) scaffolds. Ultrasonic irradiation is an important technique in the toolbox

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• with 5-iodoindole (182) in the presence of thiourea and a recyclable CuO nanoparticle catalyst (Scheme 26) [116]. This heterogeneous catalysis strategy bypasses the use of unpleasant aryl thiols, which are generally coupled with other aryl halides in the presence of transition-metal catalysts for

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• bond functionalization reaction sequence with triazole-bearing aryl iodide 140, catalyzed by alloy-structured Pd/Cu bimetallic nanoparticles stabilized by a binaphthyl moiety, Pd/Cu-BNP 139. The Pd/Cu-BNP nanoparticles 139 were demonstrated to be an efficient and recyclable catalyst, and triazoles

• methodology for aerobic C–H activation; ii) PEG as green and recyclable reaction medium; and iii) a reusable palladium catalyst complex [65]. Fully functionalized 1,2,3-triazolo-fused chromenes 162, 164, and 166 were regioselectively prepared in moderate yield. The isoindoline-fused triazoles 164 were

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

Heterogeneous photocatalytic cyanomethylarylation of alkenes with acetonitrile: synthesis of diverse nitrogenous heterocyclic compounds

• Guanglong Pan,
• Qian Yang,
• Wentao Wang,
• Yurong Tang and
• Yunfei Cai

Beilstein J. Org. Chem. 2021, 17, 1171–1180, doi:10.3762/bjoc.17.89

• .17.89 Abstract A visible light-mediated heterogeneous photocatalytic cyanomethylarylation of alkenes with acetonitrile has been established using K-modified carbon nitride (CN-K) as a recyclable semiconductor photocatalyst. This protocol, employing readily accessible alkyl N-hydroxyphthalimide (NHPI

• photocatalysis; recyclable; Introduction Nitrogenous heterocyclic compounds, such as indolines [1][2][3][4], oxindoles [5][6][7], isoquinolinones [8][9][10], and isoquinolinediones [11][12], are pivotal structural motifs in numerous pharmaceuticals, agrochemicals, and bioactive natural products. The oxidative

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

• excellent both in terms of enantioselectivities and conversions (up to 98%; up to 83% ee; Table 28). The reuse of the heterogeneous catalyst has not been studied in this case. In 2020, our group reported the first heterogeneous polystyrene-supported recyclable catalyst for the asymmetric conjugate additions

• , 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

• first heterogeneous polystyrene-supported recyclable catalyst for asymmetric conjugate addition reactions of arylboronic acids to five and six-membered enones. In our laboratory, we also attempted to perform this reaction under flow conditions. However, the change from batch to flow arrangement itself

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles

• Bingbing Lai,
• Meng Ye,
• Ping Liu,
• Minghao Li,
• Rongxian Bai and
• Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238

• tricyclic indoles bearing 3,4-fused seven-membered rings, 2‑arylpyridines, aminonaphthalenes and 3-phenylisoquinolines. In addition, this catalyst showed to be recyclable and could be reused several times without significant loss in activity during the course of the reaction process. Keywords: biomass

• , ring-closing, metathesis, cycloadditions, radical reactions and microwave-assisted reactions [38][39][40]. In this work, we attempt to develop a greener, simpler, more efficient and recyclable system to synthesize arylpyridine derivatives. Initially, the reaction of acetophenone (5a) and 1,3

One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?

• Isaline Bonnin,
• Raphaël Mereau,
• Thierry Tassaing and
• Karine De Oliveira Vigier

Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143

• increased production of insoluble byproducts. The productivity of isosorbide can reach 40.2 g·L−1·h−1with a purity of 73%. The recycling of the metal-supported catalyst (Ru/C) was studied and a high catalytic activity decrease was observed after the first run, showing that the catalyst was not recyclable

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

• -workers to be an effective, stable, and recyclable HPCat for a large scope of arene and heteroarene functionalisation reactions, traditionally performed with transition metal complexes (Scheme 2) [128]. The group were able to bifunctionalise N-phenylpyrrole with a variety of functional groups at room

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99