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Search for "stability" in Full Text gives 1267 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Graphical Abstract
  • isoelectronic π-system (i.e., the same total number of rings). Isoacenofurans show limited stability due in part to the highly reactive 1,3-carbons of the furan ring. Both 1,3-dimesitylisobenzofuran and 1,3-di(2’,4’,6’-triethylphenyl)isobenzofuran, each bearing sterically congesting ortho-alkyl groups on their
  • stabilized hexacenes. Their beautiful work documented the lack of stability associated with isoanthracenofurans. Thus, their 1,3-diarylisoanthracenofurans rapidly oxidized in solution to form endoperoxides [3]. These compounds persisted longer in the solid state, but clearly the lack of stability and
  • (see Supporting Information File 1). The mesityl and 2’,4’,6’-triethylphenyl substituents both provide a strong measure of kinetic stabilization. Solution phase stability is particularly important if isoacenofurans are to be utilized as thin-film organic semiconductors cast from solution. Conclusion We
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Published 17 May 2024

Synthesis of 1,4-azaphosphinine nucleosides and evaluation as inhibitors of human cytidine deaminase and APOBEC3A

  • Maksim V. Kvach,
  • Stefan Harjes,
  • Harikrishnan M. Kurup,
  • Geoffrey B. Jameson,
  • Elena Harjes and
  • Vyacheslav V. Filichev

Beilstein J. Org. Chem. 2024, 20, 1088–1098, doi:10.3762/bjoc.20.96

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  • characterised as the most potent inhibitor of human CDA, but the quick degradation in water limited the applicability as a potential therapeutic. To improve stability in water, we synthesised derivatives of phosphapyrimidine nucleoside having a CH2 group instead of the N3 atom in the nucleobase. A charge
  • -neutral phosphinamide and a negatively charged phosphinic acid derivative had excellent stability in water at pH 7.4, but only the charge-neutral compound inhibited human CDA, similar to previously described 2'-deoxyzebularine (Ki = 8.0 ± 1.9 and 10.7 ± 0.5 µM, respectively). However, under basic
  • scaffold, compounds Va–c (Figure 1B), in which the N3 atom present in the nucleobase of IV is replaced by CH2. We assumed that this change should not significantly affect the inhibitory potential but rather increase the stability of the target nucleosides in water and allow chemical incorporation into
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Published 15 May 2024

Light on the sustainable preparation of aryl-cored dibromides

  • Fabrizio Roncaglia,
  • Alberto Ughetti,
  • Nicola Porcelli,
  • Biagio Anderlini,
  • Andrea Severini and
  • Luca Rigamonti

Beilstein J. Org. Chem. 2024, 20, 1076–1087, doi:10.3762/bjoc.20.95

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  • results on various substrates, the direct use of molecular bromine poses sustainability challenges. Its innate reactivity requires stringent safety protocols during transportation, storage, and handling [24]. A related concern involves the stability of the diluting media, often requiring the use of toxic
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Published 14 May 2024

Novel route to enhance the thermo-optical performance of bicyclic diene photoswitches for solar thermal batteries

  • Akanksha Ashok Sangolkar,
  • Rama Krishna Kadiyam and
  • Ravinder Pawar

Beilstein J. Org. Chem. 2024, 20, 1053–1068, doi:10.3762/bjoc.20.93

Graphical Abstract
  • the most versatile solvent to exhibit the best photoswitching behaviour which is beneficial for real-life energy storage applications. Additionally, the stability and reversibility of the photoswitching system with elongated unsaturated bridges have also been assessed. By means of the studied
  • /kg), and TBR barrier (121.76 kJ/mol) of prototype NBD/QC in the gas phase. The outcomes render useful insights into the stability and properties of bicyclic diene-based photoswitches having elongated unsaturated bridges and indeed paves the way for the rational design of practical MOST systems
  • solvents on the photoswitching properties has also been investigated for a real-life MOST application. The stability and the reversibility of the photoswitches have also been verified to attain a closed cyclic photoswitching process for practical MOST system. Results and Discussion As can be seen from
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Published 13 May 2024

Structure–property relationships in dicyanopyrazinoquinoxalines and their hydrogen-bonding-capable dihydropyrazinoquinoxalinedione derivatives

  • Tural N. Akhmedov,
  • Ajeet Kumar,
  • Daken J. Starkenburg,
  • Kyle J. Chesney,
  • Khalil A. Abboud,
  • Novruz G. Akhmedov,
  • Jiangeng Xue and
  • Ronald K. Castellano

Beilstein J. Org. Chem. 2024, 20, 1037–1052, doi:10.3762/bjoc.20.92

Graphical Abstract
  • studies. Conversion of the DCPQs into hydrogen-bonding capable DPQDs results in modulation of frontier MO energies, higher molar extinction coefficients, enhanced crystallinity, and on-average higher thermal stability (where in some cases the 5% weight loss temperature is increased by up to 100 °C
  • and charge injection/extraction processes [7]. The additional merits of H-bonding designs in organic optoelectronic materials include higher thermal stability, synergistic stabilizing effects with π-stacking interactions, etc. [8]. Acenes and N-heteroacenes are two prominent π-conjugated scaffolds for
  • functionality as well as Buchwald–Hartwig amination involving aryl halides. Thermal studies Thermal stabilities of DCPQs 1a–6a and DPQDs 1b–7b were evaluated using thermogravimetric analysis (TGA; Figure 2 and Table S4 in Supporting Information File 1). The thermal stability of the DCPQs is attributed to their
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Published 08 May 2024

Auxiliary strategy for the general and practical synthesis of diaryliodonium(III) salts with diverse organocarboxylate counterions

  • Naoki Miyamoto,
  • Daichi Koseki,
  • Kohei Sumida,
  • Elghareeb E. Elboray,
  • Naoko Takenaga,
  • Ravi Kumar and
  • Toshifumi Dohi

Beilstein J. Org. Chem. 2024, 20, 1020–1028, doi:10.3762/bjoc.20.90

Graphical Abstract
  • attractive class of reagents due to their stability, accessibility, and diverse chemical reactivity [1]. Diaryliodonium(III) salts, in particular, have been widely recognized as efficient arylating reagents for a range of carbon, nitrogen, oxygen, sulfur, and other nucleophiles, and can be employed in the
  • modifying their physical properties, and stability and controlling the reactivity of arylation processes, as demonstrated in various studies [9][10]. For instance, the Gaunt group reported that the use of a fluoride counterion in diaryliodonium(III) salt can trigger phenol O-arylation by activating the
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Letter
Published 03 May 2024

Innovative synthesis of drug-like molecules using tetrazole as core building blocks

  • Jingyao Li,
  • Ajay L. Chandgude,
  • Qiang Zheng and
  • Alexander Dömling

Beilstein J. Org. Chem. 2024, 20, 950–958, doi:10.3762/bjoc.20.85

Graphical Abstract
  • , metabolic stability, conformational rigidity, and potency [7][8][9]. Recently, the use of the tetrazole moiety in drug development has been increased and exhibited prevalent occurrence in bioactive compounds; being present in more than 20 marketed drugs with a very broad range of biological activities such
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Published 29 Apr 2024

Synthesis and properties of 6-alkynyl-5-aryluracils

  • Ruben Manuel Figueira de Abreu,
  • Till Brockmann,
  • Alexander Villinger,
  • Peter Ehlers and
  • Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

Graphical Abstract
  • therefore plays a very important role in many vital biological processes in the human body and other life forms. Uracil is rarely found in DNA, due to its lower stability and mutagenic properties when mismatched with guanine [2][3][4][5]. This fact can be used to differentiate between RNA and DNA-dependent
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Published 22 Apr 2024

(Bio)isosteres of ortho- and meta-substituted benzenes

  • H. Erik Diepers and
  • Johannes C. L. Walker

Beilstein J. Org. Chem. 2024, 20, 859–890, doi:10.3762/bjoc.20.78

Graphical Abstract
  • candidates in development. Bioisosteres of para-benzenes, such as those based on bicyclo[1.1.1]pentane, are now very common and can be used to increase aqueous solubility and improve metabolic stability, among other benefits. Bioisosteres of ortho- and meta-benzenes were for a long time severely
  • early drug discovery process. In many cases, the primary aim is the enhancement of biological activity, but in others, modulation of other critical properties such as aqueous solubility, metabolic stability, polarity, or lipophilicity is the target. In the latter cases, there is often a desire to retain
  • partition coefficient (logP) as a measure of compound polarity, aqueous solubility (desired value: >200 μM [26]), and intrinsic clearance rate (CLint, lower indicates higher metabolic stability) as a measure of metabolic stability. Additional properties will be discussed if comparative values have been
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Published 19 Apr 2024

Advancements in hydrochlorination of alkenes

  • Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

Graphical Abstract
  • alkene reactivity is essential. Two reactivity scales for alkenes are available in the literature, one considering the reactivity of the alkene itself (Mayr scale) [25] and the other the stability of the corresponding cation after protonation (hydride affinities) [26]. In the polar hydrochlorination
  • ). Conveniently, these parameters are freely available on Mayr's database of reactivity parameters [28]. On the other hand, one can assess the stability of the in situ-generated cation. The greater its stability, the easier the protonation of the alkene will be, making it more reactive towards hydrochlorination
  • , HCl gas was bubbled through neat alkene 1 for several hours, as depicted in Scheme 3A [35]. This example highlights an intriguing regioselectivity that might have been challenging to predict through a simple analysis of the stability of the corresponding cations. Alternatively, the HCl gas was bubbled
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Published 15 Apr 2024

Synthesis of new representatives of A3B-type carboranylporphyrins based on meso-tetra(pentafluorophenyl)porphyrin transformations

  • Victoria M. Alpatova,
  • Evgeny G. Rys,
  • Elena G. Kononova and
  • Valentina A. Ol'shevskaya

Beilstein J. Org. Chem. 2024, 20, 767–776, doi:10.3762/bjoc.20.70

Graphical Abstract
  • biomacromolecule [10][11]. In this context, fluorinated porphyrins have attracted considerable interest due to their biological properties such as low toxicity, metabolic stability, and cellular uptake. The introduction of a fluorine atom into the molecule is the feasibility to change drastically its biological
  • meso-pentafluorophenyl-substituted porphyrins. Carboranes, due to their unique physical and chemical properties such as high chemical and biological stability [28][29], three-dimensional aromaticity [30][31], low toxicity [28], high hydrophobicity, and enriched boron content [32][33] are perspective
  • compounds in drug development [34][35][36][37]. Owing to their stability, carboranes also may increase the in vivo stability and bioavailability of pharmaceuticals that might otherwise rapidly metabolize [38]. The functionalization of porphyrins with carborane clusters provides dual-action photo(radio
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Published 12 Apr 2024

Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins

  • Zhongwei Hua,
  • Nan Liu and
  • Xiaohui Yan

Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68

Graphical Abstract
  • ) ameliorates myocardial ischemia or myocardial infarction induced by coronary ligation. Although crocin and crocetin derivatives exhibit a diverse scope of biological activity, they are characterized by poor stability and low bioavailability, which has significantly impeded clinical developments. Recently
  • , novel pharmaceutical systems, such as liposomes, microcapsules, and nanoparticles, were adopted to enhance the stability and bioavailability of these compounds [13][14][15]. To find a sustainable way of supplying crocins, researchers have developed various approaches to produce them, including plant
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Published 09 Apr 2024

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

  • Senze Qiao,
  • Zhongyu Cheng and
  • Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

Graphical Abstract
  • stability, etc. Emerging research methods on bioinformatics, computational modeling, deep learning, protein engineering, and high-throughput screening will accelerate the pace of enzyme discovery to provide a broader platform of tools for employing chemoenzymatic strategies [64][87][88][89]. More
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Published 04 Apr 2024

SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

  • Julien Borrel and
  • Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

Graphical Abstract
  • ]. On the other hand, the nature of the alkene might be limited as it would strongly influence the oxidation potential of the carbon radical and the stability of the resulting carbocation. Recently, we reported the first successful application of an RPC strategy for the azido-alkynylation of styrenes
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Commentary
Published 03 Apr 2024

Organic electron transport materials

  • Joseph Cameron and
  • Peter J. Skabara

Beilstein J. Org. Chem. 2024, 20, 672–674, doi:10.3762/bjoc.20.60

Graphical Abstract
  • orthogonal processing. One of the biggest challenges with n-type materials is air stability. This is explained by the redox potentials of water (−0.66 V vs standard calomel electrode (SCE)) and oxygen (+0.024 V vs SCE, +0.57 V vs SCE) [2][3]. Therefore, it has been observed that once the overpotential
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Editorial
Published 28 Mar 2024

HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines

  • Luan A. Martinho and
  • Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2024, 20, 628–637, doi:10.3762/bjoc.20.55

Graphical Abstract
  • is known for its chemical and thermal stability. Herein, we report a straightforward approach to the GBB-3CR using HPW as catalyst in ethanol under microwave (μw) heating. This convenient environmentally benign methodology is broad in scope, provides the heterobicyclic products in high yields (up to
  • green catalyst with greater chemical and thermal stability in comparison to other heteropolyacids [43]. HPW has been shown to catalyze MCRs in the synthesis of heterocyclic compounds with high efficiency and chemoselectivity (Figure 2), including functionalized benzo[c]chromeno[2,3-a]phenazine [44
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Published 19 Mar 2024

Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

  • Yasuhiro Oishi,
  • Motoharu Kitatani and
  • Koichi Kusakabe

Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49

Graphical Abstract
  • the potential energy surface, a curved conformation (conformation 2 in Figure 1d) exists. Our previous results suggested that conformation 2 is a metastable state. The relative stability of these conformations is known to vary depending on the surrounding environment, e.g., solvents and solutes [9
  • ]. Actually, the presence of solutes consisting of water and proteins improves the stability of conformation 2. This stabilization is explained partly by the formation of hydrogen bonds between water molecules and PASE. Conformation 2 increases the number of sites where hydrogen bonds can form with water
  • molecules because the chain portion of PASE turns upward. Therefore, the stabilization energy of hydrogen-bond formation is greater in conformation 2 than in conformation 1. To improve the stability of conformation 2, hydration effects by electrostatic interactions between PASE and the solvent are also
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Published 11 Mar 2024

Switchable molecular tweezers: design and applications

  • Pablo Msellem,
  • Maksym Dekthiarenko,
  • Nihal Hadj Seyd and
  • Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

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Published 01 Mar 2024

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

  • Ruichen Lan,
  • Brock Yager,
  • Yoonsun Jee,
  • Cynthia S. Day and
  • Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

Graphical Abstract
  • tackle catalyst stability by changing the chloride scavenger [23] or adding other coordinating moieties [24][25]. Hartwig et al. have argued that a Brønsted acid generated in situ from metal triflates may be the “real” catalyst promoting some alkene functionalizations [26]. Therefore, the possibility of
  • other in the NMR spectrum. Although we observed reaction inhibition in a number of instances with [JPhosAu(NCCH3)]SbF6 we have never yet observed the formation of this byproduct. On the one hand, this is a testament to the high stability of gold supported by JPhos, on the other hand, it suggests as yet
  • utilizing a dinuclear gold phosphine. These enhancements are likely correlated with increased catalyst stability. The earliest reports of alkene hydroamination revealed NHC’s and JPhos (t-Bu2)P(o-biphenyl) as the most active ligands [12][13][14], but this was in comparison to Ph3P which has since been
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Published 29 Feb 2024

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

  • Alexander S. Hampton,
  • David R. W. Hodgson,
  • Graham McDougald,
  • Linhua Wang and
  • Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

Graphical Abstract
  • present in many agrochemical and pharmaceutical products owing to the beneficial properties imparted such as increased metabolic stability, lipophilicity and bioavailability of the bioactive entity [1][2][3]. In 2018, 30% of FDA approved drugs contained at least one fluorine atom, with an average of 2.7
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Published 28 Feb 2024

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

  • Eiichi Kayahara,
  • Yoshiyuki Mizuhata and
  • Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

Graphical Abstract
  • -conjugated molecules, CPPs with shorter conjugations have lower oxidation potentials than larger CPPs, and the first and the second oxidation potentials of [5]CPP are by 0.69 and 0.51 V lower than those of [10]CPP, respectively [43]. The other is the stability of the CPP dications. Since the dications are
  • . However, the low solubility and stability of the dication in polar solvents prevented confirmation of the solvent effect. To clarify the additional interaction in the complex, the electrochemical analysis of the [10]CPP⊃[5]CPP2+[B(C6F5)4–]2 was examined by using cyclic voltammetry, which was performed in
  • transition corresponds to the CT band. The structure and stability of [10]CPP⊃[5]CPP2+ were estimated by DFT calculations at the ωB97-XD/6-31G* level of theory. Three isomeric structures were optimized, of which complex 1, with two CPPs aligned in parallel, is the most thermodynamically stable (Figure 5a
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Letter
Published 23 Feb 2024

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

Graphical Abstract
  • nanocompounds, instead picking graphene oxide (GO), due to its unique morphology and high chemical stability (Scheme 20) [112]. The graphene oxide was decorated with CuBr nanoparticles, which had already shown great catalytic potential, forming the GO–CuBr complex that was utilized for the synthesis of BIMs
  • greatly diminished the conversion rates of BIMs, while replacing SDS with different surfactants had no effect on the reaction profile. Even though a large amount of 0.5 g of the LASSC nanocatalyst was employed, it displayed impressive stability, since it could be retrieved and reused upwards of 11 times
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Published 22 Feb 2024

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

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  • Carlos R. Azpilcueta-Nicolas Jean-Philip Lumb Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada 10.3762/bjoc.20.35 Abstract Due to their ease of preparation, stability, and diverse reactivity, N-hydroxyphthalimide (NHPI) esters have found
  • -hydroxyphthalimide (NHPI) esters (3) have emerged as convenient alternatives to Barton esters (Scheme 1) due in part to their ease of synthesis and greater stability (N–O BDE ≈ 75 kcal/mol) [28]. Their use as radical precursors was first described by Okada and colleagues in 1988 [29], who showed that C(sp3)-centered
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Perspective
Published 21 Feb 2024

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

  • Eugeny Ivakhnenko,
  • Vasily Malay,
  • Pavel Knyazev,
  • Nikita Merezhko,
  • Nadezhda Makarova,
  • Oleg Demidov,
  • Gennady Borodkin,
  • Andrey Starikov and
  • Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

Graphical Abstract
  • ). This is also the basic compound used in the transformations that are studied in this work due to the high kinetic stability and good solubility ensured by the tert-butyl groups. The largest positive charge of the C(1)–C(2)–C(3) segment is concentrated at the C(2) atom. The charge at the other
  • the geometry without imposing symmetry restrictions, followed by analyzing the stability of the DFT wave function. The images of the molecular structures in Figure 1 and Figure S6, Supporting Information File 1, were obtained using the Chemcraft program [35]. DFT-calculated molecular geometry (B3LYP/6
  • and 6. Relative stability of the tautomers 7 and 7a,b of quinoxaline[2,3-b]phenoxazine calculated at the DFT B3LYP/6-311++G(d,p) level. Preparation of quinoxaline[2,3-b]phenoxazine (7) from 2-amino-3H-phenoxazin-3-one (8) [10] and 2-ethoxy-3H-phenoxazin-3-one (9) [11], respectively. Triphenodioxazine
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Published 21 Feb 2024

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

Graphical Abstract
  • the organic product along with inorganic species [41][42][43][44]. Over the years, many efforts were thus devoted to the synthesis of thiepine derivatives with increased thermal stability, with the aim to disfavor the formation of the transient thianorcaradiene intermediate as a way to prevent the
  • stability. Conversely, selenepine 28c and selenepine Se-oxide 29c were quantitatively converted into the seco-HBC 31 by thermal activation at 200 °C for 5 min, as evidenced by UV–visible absorption and HPLC monitoring. SO-extrusion from thiepine S-oxide 29b was also successfully triggered in the solid state
  • , as well as the oxidation state of the embedded chalcogen atom, allows controlling the stability of the heteropine, and thus its propensity to undergo thermal extrusion. Although beyond the scope of this review, it is noteworthy that the authors successfully converted the selenepine Se-oxide 29c into
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Published 15 Feb 2024
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