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

• of the iodide anion generated molecular iodine which reacted with 39 to furnish unstable hypoiodous anhydride 40, thereby triggering the key CO2 extrusion. The resulting C(sp2)-centered radical 42 underwent a SET anodic oxidation/cyclization/deprotonation sequence to yield the oxadiazole derivative

2-Heteroarylethylamines in medicinal chemistry: a review of 2-phenethylamine satellite chemical space

• Carlos Nieto,
• Alejandro Manchado,
• Ángel García-González,
• David Díez and
• Narciso M. Garrido

Beilstein J. Org. Chem. 2024, 20, 1880–1893, doi:10.3762/bjoc.20.163

• 2-aminoethylpyrrole (Scheme 7) hits were elaborated and tested in a stopped-flow CO2 hydrase assay. Comparing this pyrrole family with original histamine inferred a decrease in selectivity towards the hCA VII isoform, while activity was not affected significantly. Tryptamine derivatives, i.e

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

• . Romão Ramalho, 59, 7000-671 Évora, Portugal 10.3762/bjoc.20.145 Abstract A new paradigm for energy is underway demanding decarbonized energy systems. Some of them rely on emerging electrochemical devices, crucial in hydrogen technologies, including fuel cells, CO2 and water electrolysers, whose

• exchange membrane devices [5][6], such as proton exchange membrane fuel cells (PEMFCs) [3][7][8][9], due to their high-power density and high power-to-weight ratio, and CO2 electrolysers, which can reduce the polluting gas CO2 and produce syngas from the co-electrolysis of CO2 and water [10][11], or water

• molecular cages [46][47] and at porous materials, as linkers in metal-organic frameworks (MOFs) [48], used in the evaluation of the cycloaddition of CO2 to epoxides [49] and CO2 uptake [50]. Taking in consideration the strategy of the incorporation of dopants to promote the proton conduction in Nafion

Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds

• Ka-Lung Hung,
• Leong-Hung Cheung,
• Yikun Ren,
• Ming-Hin Chau,
• Yan-Yi Lam,
• Takashi Kajitani and
• Franco King-Chi Leung

Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142

• prepared by ejecting 5.0 wt % DAn solutions onto a bioinert glass-bottomed Petri dish by the shear-flow method, rinsing with PBS, and incubating with human-bone-marrow-derived mesenchymal stem cells (hBM-MSCs) at 37 °C and 5% CO2 for 3 days. hBM-MSCs have demonstrated importance in controlled

• (Gibco). Then, hBM-MSCs (Lonza) were added to the culture dish and cultured for 3 days at 37 °C and 5% CO2 in an incubator. After incubation, the DAn macroscopic scaffold with cells attached was used directly for fluorescent microscopy measurements. UV–vis-absorption-spectral changes of DAn in THF

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• ]. Photoexcitation of the Ir(III) catalyst I with blue light resulted in the photoexcited Ir(III)* catalyst, which was capable of performing a single-electron reduction on N-acyloxyphthalimide, promoting decarboxylation, releasing CO2, a methyl radical, anionic phthalimide and an Ir(IV) species. The resultant methyl

Electrophotochemical metal-catalyzed synthesis of alkylnitriles from simple aliphatic carboxylic acids

• Yukang Wang,
• Yan Yao and
• Niankai Fu

Beilstein J. Org. Chem. 2024, 20, 1497–1503, doi:10.3762/bjoc.20.133

• then extrude CO2 to generate the alkyl radical. Concurrently, Cu(II)–CN species are produced in the presence of cyanide anion through anodic oxidation. At this stage, Cu(II)–CN species are believed to capture alkyl radicals and the product would be readily generated via reductive elimination from the

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• mechanism involves C–O bond activation of tertiary oxalates. It requires [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 and NiCl2⋅DME along with dtbbpy ligand. The reaction commences with single-electron oxidation of cesium oxalate initiated by *[Ir(III)] photocatalyst. This transfer leads to the elimination of two CO2

Sustainable tandem acylation/Diels–Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

• Ayhan Yıldırım

Beilstein J. Org. Chem. 2024, 20, 1308–1319, doi:10.3762/bjoc.20.114

• importance in intramolecular Diels–Alder reactions, the effects of solvents such as glycerol, polyethylene glycol, organic carbonates, deep eutectic solvents, supercritical CO2 and H2O have recently been extensively studied [65][66][67]. Recently, attention has also been drawn to photoinduced oxidative [4

Carbonylative synthesis and functionalization of indoles

• Alex De Salvo,
• Raffaella Mancuso and
• Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

• time, Wu and co-workers contributed to the introduction of two new syntheses of N-aroylindole derivatives by means of nickel catalysis. In 2021, they reported a nickel-catalyzed carbonylative cyclization of 2-nitroalkynes and aryl iodides with Co2(CO)8 as the CO source. The reaction was performed in

Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium

• Kairi Umeda,
• Naoaki Kurisawa,
• Ghulam Jeelani,
• Tomoyoshi Nozaki,
• Kiyotake Suenaga and
• Arihiro Iwasaki

Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57

• antitrypansomal assay The bloodstream form of Trypanosoma brucei rhodesiense strain IL-1501 was cultured at 37 °C under a humidified 5% CO2 atmosphere in HMI-9 medium supplemented with 10% heat-inactivated fetal bovine serum (FBS) [8][9]. For in vitro studies, compounds were dissolved in DMSO and diluted in

• , containing 50 μL of culture medium. Subsequently, 50 μL of a parasite suspension with a concentration of 4.0 × 104 cells/mL was introduced into each well. Cultures were incubated for 69 h at 37 °C under a humidified 5% CO2 atmosphere. After this time, 10 μL of resazurin (12.5 mg resazurin (Sigma) dissolved

• assay In a manner analogous to [7], WI-38 cells were cultured at 37 °C with 5% CO2 in DMEM (Nissui) supplemented with 10% heat-inactivated FBS, 100 units/mL penicillin, 100 μg/mL streptomycin, 0.25 μg/mL amphotericin, 300 μg/mL ʟ-glutamine, and 2.25 mg/mL NaHCO3. Cells were seeded at 4 × 103 cells/well

Synthesis of photo- and ionochromic N-acylated 2-(aminomethylene)benzo[b]thiophene-3(2Н)-ones with a terminal phenanthroline group

• Vladimir P. Rybalkin,
• Sofiya Yu. Zmeeva,
• Lidiya L. Popova,
• Irina V. Dubonosova,
• Olga Yu. Karlutova,
• Oleg P. Demidov,
• Alexander D. Dubonosov and
• Vladimir A. Bren

Beilstein J. Org. Chem. 2024, 20, 552–560, doi:10.3762/bjoc.20.47

• absorption and fluorescence spectra of 2a–c were studied by the action of d-metal perchlorates (Zn2+, Hg2+, Cu2+, Cd2+, Ni2+, Co2+ and Fe2+) in acetonitrile (2a and 2b) and DMSO (2c). Exclusively Fe2+ caused an appearance of new broad long-wavelength absorption bands at 480–530 nm with a contrast naked-eye

• spectrophotometer. Electronic emission spectra were recorded on a Varian Cary Eclipse spectrofluorimeter. Acetonitrile and DMSO (spectral pure grade), Cd2+, Hg2+, Cu2+, Zn2+, Ni2+, Co2+ and Fe2+ perchlorates as well as TBAX (X = F, Cl, Br, I, CN, SCN, NO3) salts (Aldrich) were used to prepare the solutions. The

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

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• CO2. Radical 12 undergoes intermolecular addition to the olefin acceptor 13 to form radical intermediate 14. Finally, under reductive conditions radical 14 can undergo hydrogen atom transfer (HAT) or sequential electron transfer and proton transfer (ET/PT) to form the conjugate addition product 15

• ester 10, regenerating pyridine 137 while forming alkyl radical 12, CO2 and phthalimide–B(pin) adduct 139. Subsequently, radical–radical coupling between 12 and one equivalent of 138 affords dihydropyridine 140, which upon re-aromatization, facilitated by ZnCl2 acting as a Lewis acid, yields product 141

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• cytomegalovirus (CMV) promoter. Then, the Mammalian Protein Expression core facility at the University of Gothenburg transfected this plasmid into FreeStyle™ CHO-S cells (Cat nr R80007, ThermoFisher Scientific). Cells were cultured in Freestyle™ CHO medium at 37 °C in 5% CO2 in Optimum GrowthTM flasks (Thomson

Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C₇₀ production

• Cristina Castanyer,
• Anna Pla-Quintana,
• Anna Roglans,
• Albert Artigas and
• Miquel Solà

Beilstein J. Org. Chem. 2024, 20, 272–279, doi:10.3762/bjoc.20.28

• the hole is closed restoring the original cage. Among the species that have been incarcerated with this procedure, we can find He, Ne, Ar, Kr, H2, N2, O2, HF, CO, CO2, H2O, H2O2, CH4, NH3, HCOH, HCCH, and CH3OH [26][27]. The encapsulation of atoms or small molecules inside the fullerene has been found

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• formation of DBDAP, prompted us to test alternative CO surrogates. When the reaction was performed using Co2(CO)8 (0.3 equiv) in the presence of DBU, the intermediate 3a was isolated in 35% yield, but again no DBDAP 4 was obtained (entry 8, Table 1). Formic acid, an effective CO surrogate [20][22], was also

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• overnight, then quenched by addition of dry ice (solid CO2) and concentrated under reduced pressure. The residue was co-concentrated with toluene (3 mL), dried in vacuo, dissolved in anhydrous pyridine (3 mL per 0.1 mmol of sialyl donor), and acetic anhydride (3 mL per 0.1 mmol of sialyl donor) was added

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• synthesis of carbonates from CO2 [24][25][26] and the synthesis of oxazolidines from isocyanates and epoxides [27]. Furthermore, their application in primary hydroxy group selective acylation of diols [28] and their use as organophotoredox catalysts [29][30] is known. The latter mentioned catalysts are

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• . An EDA complex was formed through non-covalent interaction between the redox ester 10 and n-Bu4NI (Scheme 7). Subsequently, upon the photoexcitation, radical pairs I were generated via a SET process, accompanied by the liberation of CO2 and the phthalimide anion. The recombination of the alkyl

• -unsaturated phthalimide 33a. Simultaneously, radical III of the catalyst was also formed, accompanied by the extrusion of CO2. Subsequently, the alkyl radical A added to the carbon–carbon triple bond of enynal 32g, resulting in the formation of a vinyl radical intermediate B, followed by a 5-exo-trig

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• concentration of this greenhouse gas by upcycling. Selectivity towards CO2-reduction products is highly desirable, although it can be challenging to achieve since the metal-hydrides formation is sometimes favored and leads to H2 evolution. In this work, we designed a cobalt-based catalyst, and we present herein

• its physicochemical properties. Moreover, we tailored a fully earth-abundant photocatalytic system to achieve specifically CO2 reduction, optimizing efficiency and selectivity. By changing the conditions, we enhanced the turnover number (TON) of CO production from only 0.5 to more than 60 and the

• ) complex; earth-abundant; hexafluoropropanol; photocatalytic CO2 reduction; Introduction Solar energy conversion into chemical energy addresses the issues of energy shortage with the exploitation of renewable sources [1]. Photoinduced CO2 reduction is included in the vast research field of artificial

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• frequency calculations. Cell culture RAW 264.7 cells were maintained in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 50 U/mL penicillin, and 50 μg/mL streptomycin at 37 °C in a humidified 5% CO2 atmosphere. Test samples (compounds 1–3, 6, and 7) were prepared to

• × 104 cells/well 24 hours before adding samples. The cells were treated with compound 7 at concentrations 0.25, 1, 2.5, 10, 25, and 50 µM for 24 h and then 0.2 mg/mL MTT solution was added after incubating for 3 h at 37 °C in a humidified 5% CO2 atmosphere, the culture supernatants were removed. The

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• derivatives with CO2 using 1,2,3-triazol-5-ylidene copper(I) complexes (tzNHC–Cu) as the catalyst followed by treatment with alkyl iodide to obtain the corresponding esters in moderate to very good yields. The catalytic activity of (tzNHC–Cu) was found to be better than the imidazol-2-ylidene copper(I

• heterocyclic compounds with CO2 resulting in higher yields than those obtained with the imidazolylidene carbene ligand, IPr (Scheme 70). 2.7 C(sp2)–H Alkenylation and allylation In 2016, Chang and co-worker [93] achieved an NHCs–Cu-catalyzed efficient C(sp2)–H allylation of polyfluoroarenes 183 and

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• SCE (1c) were readily reduced and dehalogenated products obtained in excellent yields (70–92%) (Figure 11A). Sodium formate was found to be a more efficient terminal reductant than trialkylamines which the authors attributed to the formation of a carbon dioxide radical anion (CO2•−) upon oxidation of

• the formate via SET to 4-DPAIPN and successive deprotonation by a second formate anion (Figure 11B). Due to its reducing nature, CO2•− (E0 = −2.2 V vs SCE) may promote the photoreductant activity either by reducing another equivalent of photocatalyst or the direct reduction of sufficiently electron

• -poor aryl halide substrates (Figure 11C). While trialkylamines like Et3N or DIPEA have been proven to be suitable terminal reductants in conPET chemistry [15][45][46][51][54], they may still decrease photoreductant activity via back electron transfer [56], in contrast to CO2•− which has an entropic

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• Cecilie Hogfeldt Jessen Jesper Bendix Theis Brock Nannestad Heloisa Bordallo Martin Jaeger Pedersen Christian Marcus Pedersen Mikael Bols Department of Chemistry & Niels Bohr Institute, University of Copenhagen, 2100 København Ø, Denmark 10.3762/bjoc.19.78 Abstract Carbon dioxide (CO2) emissions

• , are studied as potential CO2 capture agents due to their unique molecular structures and high selectivity towards CO2. In this paper we have investigated binding efficiency of a number of cyclodextrins towards CO2. It is found that the crystal structure of α-cyclodextrin with CO2 has a 1:1

• stoichioimetry and that a number of simple and modified cyclodextrins bind CO2 in water with a Kg of 0.18–1.2 bar−1 (7–35 M−1) with per-O-methyl α-cyclodextrin having the highest CO2 affinity. Keywords: carbon dioxide; crystals; cyclodextrin; gas binding; Introduction The concentration of carbon dioxide (CO2