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

• and development of a visible light-assisted modular photo-flow reactor with a seamlessly integrated post-synthetic work-up procedure enabling the efficient synthesis of dihydropyranones from furfuryl alcohols. The reaction uses sun light as green energy source, and the novel photo-flow reactor

• ], spirulina [16], Ti(OiPr)4/t-BuOOH [17], VO(acac)2)/t-BuOOH [18], and enzymatic oxidation [19] etc., which may compromise the environmental benefits (Scheme 1a,b) and take longer reaction times. Alternatively, a new green pathway is necessary for the Achmatowicz reaction to be performed in a faster and safer

• manner. Towards this direction, few research groups have already reported the Achmatowicz reaction utilizing greener approaches, yet they suffered due to some limitations. Sun et al. [20] have successfully demonstrated an Achmatowicz rearrangement using electricity as a green oxidant (Scheme 1c) in a

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• , 17, and α-ᴅ-talose 18. ORTEP diagram showing 50% thermal ellipsoid probability (except for 18): carbon (gray), oxygen (red), fluorine (green), chlorine (orange), bromine (dark red), iodine (purple), and hydrogen (white). Packing arrangement of compound compound 15; a) View down the b axis; b

• ) proposed intermolecular interactions involving halogens. ORTEP diagram showing 50% thermal ellipsoid probability: carbon (gray), oxygen (red), fluorine (green), iodine (purple), and hydrogen (white). Synthesis of halogenated talopyranose analogues 13–15, and 17 that include a 2,3-cis, 3,4-cis relationship

Homogeneous continuous flow nitration of O-methylisouronium sulfate and its optimization by kinetic modeling

• Jiapeng Guo,
• Weike Su and
• An Su

Beilstein J. Org. Chem. 2024, 20, 2408–2420, doi:10.3762/bjoc.20.205

• Jiapeng Guo Weike Su An Su Key Laboratory of Pharmaceutical Engineering of Zhejiang Province, Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang

• University of Technology, Hangzhou, 310014, P. R. China State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Key Laboratory of Green Chemistry-Synthesis Technology of Zhejiang Province, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO

• Hisanori Senboku and
• Mizuki Hayama

Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203

• a novel, efficient, facile, and green organic method. Experimental General information 1H (400 MHz) and 13C (100 MHz) NMR spectra were recorded in CDCl3 or DMSO-d6 with a JEOL JNM-ECS400 FT NMR spectrometer. The chemical shifts δ are given in ppm with tetramethylsilane (δ 0 ppm) or DMSO (δ 2.50 ppm

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• (denoted by asterisk *) of HFIP in the presence of iminoiodinane 2c suggesting hydrogen bonding observed in 1H NMR spectra (CD3CN) of: 8.0 mM 2c with no HFIP (blue line), 8.0 mM 2c with 32 mM HFIP (green line), 4.0 mM of 4-(trifluoromethyl)benzenesulfonamide with 32 mM HFIP (purple line), only 32 mM HFIP

Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

• Haifeng Yu,
• Wanting Zhang,
• Xuejing Cui,
• Zida Liu,
• Xifu Zhang and
• Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

• hydrolysis reactions were carried out in the presence of 3.0 equiv of NaOH. The green approach to β-keto thioesters and β-keto amides avoids the use of harmful organic solvents, thiols and thiolacetates as well as amines, which could result in serious environmental and safety issues. Keywords: α-oxo ketene

• synthetic method for the preparation of β-keto thioesters and β-keto amides remains imperative. Organic reactions in water are an important and exciting research topic of green chemistry because water as a solvent exhibits fascinating features, such as low cost, good environmental compatibility, nontoxicity

• , such as nontoxicity, inexpensiveness, nonflammability, low volatility and good water solubility, which are consistent with the concept of green chemistry [74][75]. Therefore, we tested the reaction in the presence of PEG-400 (Table 1, entries 7–9). It was found that the reaction uniquely produced 3a in

Finding the most potent compounds using active learning on molecular pairs

• Zachary Fralish and
• Daniel Reker

Beilstein J. Org. Chem. 2024, 20, 2152–2162, doi:10.3762/bjoc.20.185

• shown in the inlet with a green bar while the times it ‘stays’ in the same cluster is shown with a light blue bar. Arrow gradient towards darker grey indicates increasing iteration number. Tree-based model navigation of chemical space. T-SNE of a representative dataset (CHEMBL232-1, Alpha-1b adrenergic

• another is shown in the inlet with a green bar while the times it ‘stays’ in the same cluster is shown with a light blue bar. Arrow gradient towards darker grey indicates increasing iteration number. Supporting Information Supporting Information File 54: Supplementary figures and tables

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• gossypii, Tripomastigote Chagas, Tcruzi amastigota, Tcruzi epimastigota, Leishmania amazonensis, and Dengue larvicida. Keywords: dihydropyrimidinone/thione/selenone; green chemistry; in silico biological profile; multicomponent reaction (MCR); thiopyrandioxide; Introduction Multicomponent reactions (MCRs

• of other sulfones of both synthetic and biological importance can be obtained by using the in this work reported efficient, multicomponent and green protocol. We postfunctionalized the typical Biginelli product using Hantzsch-type thiazole chemistry and desulfurization. Assessing drug-likeness, we

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• understand the conditions for the generation of heteroatom radicals. In addition, from the perspective of recent green chemistry, the development of environmentally friendly synthetic methods is strongly demanded. In other words, a new synthetic method should have excellent atom economy, produce no waste, be

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• , Oxfordshire, OX11 0DE, United Kingdom School of Chemistry, Trinity College Dublin, University of Dublin, College Green, Dublin 2, Ireland Department of Chemistry, Molecular Sciences Research Hub, White City Campus, Imperial College London, 82 Wood Lane, London, W12 7SL, United Kingdom Institut für Organische

• (365 nm, irradiance = 6.00 mW⋅cm−2), blue (455 nm, 5.16 mW⋅cm−2) or green (525 nm, 0.06 mW⋅cm−2) light. For the SAXS studies at high concentration, samples were irradiated in a custom-build LED light box with UV (365 nm) light at an irradiance of 1.24 mW⋅cm−2 for 3.5 h. This resulted in 98 ± 2 and 71

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• -diphenylethylene proceeded with similar efficiency, thereby excluding any radical pathway. As such, it was proposed that the catalytic electrooxidation of iodide (ENH4I = 0.41 V and 0.75 V vs Ag/AgCl in dimethylacetamide for I−/I3− and I3−/I2 redox couples) into iodine provided a green and mild tool to in situ

Development of a flow photochemical process for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence: in situ-generated 2-benzopyrylium as photoredox catalyst and reactive intermediate

• Masahiro Terada,
• Zen Iwasaki,
• Ryohei Yazaki,
• Shigenobu Umemiya and
• Jun Kikuchi

Beilstein J. Org. Chem. 2024, 20, 1973–1980, doi:10.3762/bjoc.20.173

• Transformative Research Areas (A) “Green Catalysis Science for Renovating Transformation of Carbon-Based Resources” (JP23H04908) from MEXT, Japan and a Grant-in-Aid for Young Scientists (JP19K15552) from JSPS.

Negishi-coupling-enabled synthesis of α-heteroaryl-α-amino acid building blocks for DNA-encoded chemical library applications

• Matteo Gasparetto,
• Balázs Fődi and
• Gellért Sipos

Beilstein J. Org. Chem. 2024, 20, 1922–1932, doi:10.3762/bjoc.20.168

• , no reaction was observed with indazoles and furans using the first two conditions, requiring the formation of the ketoesters 4j and 4r first, followed by the functional group interconversion (FGI) with NH2OH·HCl (Scheme 6, blue and green sections). The Riley oxidation of the furanyl derivative 2j

Novel oxidative routes to N-arylpyridoindazolium salts

• Oleg A. Levitskiy,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2024, 20, 1906–1913, doi:10.3762/bjoc.20.166

• in line with the green chemistry requirements [24]. To test the assumption, the preparative oxidation of amine A1 was performed in the potentiostatic mode at 1.6 V (vs Ag/AgCl, KCl(sat.)) in a two-compartment cell in DMF; sodium tosylate was used as a supporting electrolyte. After a charge

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• discussed in more details in chapter 2). Another recent article on the use of Brønsted acids has been reported by Vilapara et al., who employed for the first time etidronic acid (1-hydroxyethane-1,1-diphosphonic acid, HEDP) as a green catalyst. Reactions were efficient at room temperature [11]; although the

• adducts. An intriguing study is reported by Porcal et al. [35] in which they evaluate the use of 5-hydroxymethylfurfural (5-HMF, 23). Nowadays, the need to move towards more sustainable protocols is impending and the emphasis on green chemistry and on the use of renewable carbon sources is huge. Indeed

• reaction conditions. The authors performed the optimization study using 5-HMF (23), 2-aminothiazole (24) and tert-butyl isocyanide (5, Scheme 10). Inspired by a procedure reported by Demjén et al. [37], they found the best conditions using EtOH as a green solvent, trifluoroacetic acid (TFA, 20 mol %) or Yb

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• mechanism, see Supporting Information File 1). Such results with previous reports on DMSO acting as a methine source in the synthesis of heterocyclic compounds [35][36] are opening a new avenue for the green synthesis of non-substituted 5-deazaalloxazines in a pseudo MCR fashion. Conclusion In summary, we

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides

• Samuel M. G. Dearman,
• Xiang Li,
• Yang Li,
• Kuldip Singh and
• Alison M. Stuart

Beilstein J. Org. Chem. 2024, 20, 1785–1793, doi:10.3762/bjoc.20.157

• rate of decomposition was reduced significantly (green line in Figure 3). The hydrolysis of the four hypervalent iodine(V) fluorides was also investigated in acetonitrile-d3 by adding 5 equivalents of water. All four compounds decomposed to their corresponding iodosyl compounds and the order of

• (blue line), dry CDCl3 with 2.4 equivalents of dry pyridine (green line), and dry CDCl3 (red line). Order of hydrolytic stability for the four hypervalent iodine(V) fluorides. Examples of fluorination using hypervalent iodine(III) reagents 1 and 2. Preparations and reactions of hypervalent iodine(V

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• = green, N = blue, and O = red. a) Absorption and b) emission spectra of the compounds dissolved in CH2Cl2. Cyclic voltammograms of the compounds collected on ca. 1 mM solutions of the analyte in CH2Cl2 with 0.1 M Bu4NPF6 as electrolyte. The major y-axis tick mark spacing corresponds to 5 μA. Structural

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• estitmation of the HOMO/LUMO energies to shed more light on this transformation. The easy separation of the supporting electrolyte from the product will allow recycling and makes this a green transformation. Keywords: acetal formation; cyclic voltammetry; flow electrochemistry; green oxidation; polycyclic

• synthesis of polycyclic aromatic quinones by anodic oxidation as a green alternative to our previous synthesis with SIBX [18]. Results and Discussion The electrochemical reactions were performed in the Flux module of the Syrris automated modular flow system [40] which provides a controlled geometry with a

• cations B and C which have only one Clar sextet with two alternative positions. Conclusion The electrochemical oxidation of polycyclic aromatic phenols to quinones represents a green alternative to chemical oxidants. Hydrogen gas evolution can be handled by recycling of the reaction mixture through the

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• formation of a) an alkoxy-NHI which is causing a significant downfield shift of the protons in alpha-position (orange) compared to the free alcohol 2 (blue) and b) oxidation of p-tolylmethanol (3a, blue) to the aldehyde 4a (green) and carboxylic acid 4a’ (red). Reaction conditions: An equimolar mixture of

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• advance and are not recycled in the system. The amino acids are methylated either prior to tRNA binding or after. The efficiency of incorporating unnatural amino acids is lower, but Merryman and Green have demonstrated that an excess of tRNA can overcome this problem [47]. When attempting to incorporate

• core peptide is coloured in orange. Methylation of the backbone is highlighted in green. B) Three-dimensional structure of the OphMA homodimer, PDB ID: 6TCS (https://doi.org/10.2210/pdb6tsc/pdb) [99]. Overview of the protein architectures and core peptide compositions of borosin N-MTs as defined by

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• electrolysers that allow the generation of green hydrogen [12][13]. The technology behind these electrochemical devices still relies on the membrane as a key component that defines the applications and the conditions to its use [14]. Both fuel cells and water electrolyser devices depend on proton exchange

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• bioactivities including analgesic, sedative, and cytotoxic [12][13][14]. In order to identify new potential burpitides, we searched the NCBI Sequence Read Archive (SRA) for Streptophyta (all land plants and most green algae) transcriptomes that could be assembled and examined with a custom hidden Markov model

• color-coded to show localization of various molecules. Molecules in red are new to this study and predicted by MS/MS fragmentation. Ceanothine B was isolated and its structure confirmed by 1D and 2D NMR. Correlations are indicated as follows: red lines – COSY, green lines – TOCSY, pink arrows – NOSEY

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• total heat released as a function of total ligand concentration for the titration shown in the upper panel. The solid line represents the best least-square fit to experimental data using a one site model. (A) Enthalpy–entropy compensation plot of compounds 1–5 from ITC analysis. The dotted green line

• crystalline complexes. The protein is represented by orange ribbon, His53 by lines, and calcium by green sphere. Synthesis of photoswitchable LecA inhibitors. Reagents and conditions: (i) DMC, Et3N, H2O, −10 °C to rt, 8 h, 50% for 7, 40% for 10; (ii) BrCH2CH2NHBoc, K2CO3, DMF, 60 °C, 15 h, 91% for 8, 80% for

Synthesis of 2-benzyl N-substituted anilines via imine condensation–isoaromatization of (E)-2-arylidene-3-cyclohexenones and primary amines

• Lu Li,
• Na Li,
• Xiao-Tian Mo,
• Ming-Wei Yuan,
• Lin Jiang and
• Ming-Long Yuan

Beilstein J. Org. Chem. 2024, 20, 1468–1475, doi:10.3762/bjoc.20.130

• Lu Li Na Li Xiao-Tian Mo Ming-Wei Yuan Lin Jiang Ming-Long Yuan National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials; School of Chemistry and Environment, Yunnan Minzu University, Kunming, China 10.3762/bjoc.20.130 Abstract A catalyst- and

• of anilines through Brønsted acid or transition-metal-promoted conversion of 2-cyclohexanone oximes [15][16][17][18] (Scheme 1, (2)). Moreover, Strauss and co-workers described a green, multicomponent reaction of aromatic aldehydes, 2-cyclohexenone and amines to afford 2-arylmethyl N-substituted