Search results

Search for "CO" in Full Text gives 1834 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Heteroannulations of cyanoacetamide-based MCR scaffolds utilizing formamide

  • Marios Zingiridis,
  • Danae Papachristodoulou,
  • Despoina Menegaki,
  • Konstantinos G. Froudas and
  • Constantinos G. Neochoritis

Beilstein J. Org. Chem. 2025, 21, 217–225, doi:10.3762/bjoc.21.13

Graphical Abstract
  • such, it is becoming increasingly essential for synthetic methods to align with a net-zero carbon future [2][3]. Therefore, advancing C1 chemistry remains a crucial endeavor for our group [4]. In synthetic organic chemistry, C1 compounds are usually installed using CO, CO2, HCO2H, CH3OH and CH4, which
  • convergent chemistry characterized by diversity, complexity and efficiency. MCRs are compatible with C1 chemistry due to the generally great tolerance of different functional groups. They have been mostly employed in the synthesis of oxazolidinones and oxazinanones utilizing CO2 and CO [4][16][17][18][19][20
PDF
Album
Supp Info
Full Research Paper
Published 24 Jan 2025

Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

  • Seungmin Lee,
  • Minsuk Kim,
  • Hyewon Han and
  • Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

Graphical Abstract
  • advancements in the synthetic transformations of dioxazolones, with particular examples of copper salts. Keywords: amidation; copper salts; dioxazolones; electrophilic nitrogen; N-acyl nitrene; Introduction Dioxazolones, first synthesized and reported by Beck and co-workers [1], have been employed as
  • amidation Recently, Cao and co-workers reported the copper-catalyzed synthesis of 1,2,4-triazole derivatives via an N-acyl nitrene intermediate [76]. As illustrated in Scheme 3, dioxazolones 4 and N-iminoquinolinium ylides 5 served as reactive substrates, leading to the formation of various polycyclic 1,2,4
  • area of medicinal chemistry [93][94][95][96][97]. In 2018, Buchwald and co-workers unveiled the enantioselective synthesis of benzylic amines through the asymmetric Markovnikov hydroamidation of alkenes utilizing diphenylsilane in copper catalysis under mild reaction conditions [98]. Dioxazolones, as
PDF
Album
Review
Published 22 Jan 2025

Recent advances in electrochemical copper catalysis for modern organic synthesis

  • Yemin Kim and
  • Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

Graphical Abstract
  • asymmetric C(sp3)–H alkynylation of tertiary cyclic amines by merging Cu(II)/TEMPO catalysis with electrochemistry to yield chiral C1-alkynylated tetrahydroisoquinolines (THIQs) (Figure 5) [50]. As a co-catalytic redox mediator, TEMPO plays an essential role in the formation of iminium intermediate 15 and in
  • 2022, Xu and co-workers established a site- and enantioselective cyanation of benzylic C(sp³)–H bonds using an electro-photochemical strategy (Figure 7) [55]. The reaction conditions show a broad substrate tolerance, and the late-stage functionalization of complex molecules derived from natural
  • co-workers reported Cu-catalyzed asymmetric electrochemical regiodivergent cross-dehydrogenative coupling of Schiff bases and hydroquinones (Figure 9) [58]. In this approach, a chiral copper complex was used as a Lewis acid catalyst, yielding various synthetic routes for synthesizing chiral amino
PDF
Album
Review
Published 16 Jan 2025

Nickel-catalyzed cross-coupling of 2-fluorobenzofurans with arylboronic acids via aromatic C–F bond activation

  • Takeshi Fujita,
  • Haruna Yabuki,
  • Ryutaro Morioka,
  • Kohei Fuchibe and
  • Junji Ichikawa

Beilstein J. Org. Chem. 2025, 21, 146–154, doi:10.3762/bjoc.21.8

Graphical Abstract
  • JMS-T100GCV or a JEOL JMS-T200GC spectrometer. All the reactions were conducted under argon or nitrogen. Materials: Column chromatography was conducted on silica gel (Silica Gel 60 N, Kanto Chemical Co., Inc.). Toluene and N,N-dimethylformamide (DMF) were purified by a solvent-purification system
PDF
Album
Supp Info
Full Research Paper
Published 15 Jan 2025

Cu(OTf)2-catalyzed multicomponent reactions

  • Sara Colombo,
  • Camilla Loro,
  • Egle M. Beccalli,
  • Gianluigi Broggini and
  • Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

Graphical Abstract
  • . The Mannich reaction with aromatic aldehydes and cyclic amines was performed efficiently on 2-naphthol, by using SiO2-supported copper triflate under solvent-free conditions, without an additional co-catalyst or additive (Scheme 3) [17]. The treatment of stoichiometric amounts of arylaldehydes
  • counteranion. The use of a carbamate among the substrates instead of the amine allowed the synthesis of propargylcarbamates 11. This reaction, effective only for the aromatic aldehydes, did not require other co-catalysts or ligands (Scheme 8) [21]. Three-component reactions of alkynes, alkyltrifluoroborates
  • aldehyde, urea and a 1,3-dicarbonyl compound [26][27]. In these reactions, the use of catalytic Cu(OTf)2 proved to be an excellent triflate surrogate, also revealing a remarkable reuse activity. The first example of a Biginelli reaction carried out with Cu(OTf)2 catalysis was reported by Sudalai and co
PDF
Album
Review
Published 14 Jan 2025

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
  • advances in organocatalytic atroposelective syntheses. Review Atroposelective reactions via enamine and iminium activation Iminium activation was utilized in the synthesis of axially chiral styrenes. Tan and co-workers developed an atroposelective strategy toward axially chiral alkenylarenes 3 based on an
  • activation of propargylic aldehydes with catalyst Int-1. Another critical feature was the ability of the organocatalyst to promote the Z-selective isomerization of Int-2 to Int-3. In a related fashion, Wang and co-workers developed an atroposelective heterocycloaddition [19]. The iminium-activated alkynals 4
  • purities (Scheme 3). Sparr and co-workers developed an atroposelective synthesis for tetra-ortho-substituted biaryls 11 by non-canonical polyketide cyclizations [21]. This work was based on an earlier report of the team on the aldol cyclization of naphthyl-substituted unsaturated ketoaldehydes [22]. The
PDF
Album
Review
Published 09 Jan 2025

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

  • Yongming Xiong,
  • Xue Lin Ma,
  • Shilong Su and
  • Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

Graphical Abstract
  •  1) featuring three heptagons and two pentagons, with its structure confirmed by X-ray crystallography. This π-expansion approach of compound 1 differs from the method reported by Müllen and co-workers, which involves Ramirez olefination and Suzuki coupling, resulting in the expansion of a seven
  • -membered ring, and one seven-membered ring, and the third one containing three benzene rings and two seven-membered rings. The crystal structure of 3·CH2Cl2 reveals that each unit cell contains a pair of enantiomers, (M,P,M)-3 and (P,M,P)-3, co-crystallized with two molecules of CH2Cl2. Here P and M
PDF
Album
Supp Info
Full Research Paper
Published 02 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

Graphical Abstract
  • acceptor group in TADF emitters, indicating great potential for the development of highly efficient TADF molecules. In 2019, Nishida and co-workers prepared 5 D–A–D-type PhFlOP derivatives with electron-donating diarylamine or carbazole moieties in positions 2 and 8. They conducted optical and
  • 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
PDF
Album
Supp Info
Full Research Paper
Published 30 Dec 2024

Synthesis of acenaphthylene-fused heteroarenes and polyoxygenated benzo[j]fluoranthenes via a Pd-catalyzed Suzuki–Miyaura/C–H arylation cascade

  • Merve Yence,
  • Dilgam Ahmadli,
  • Damla Surmeli,
  • Umut Mert Karacaoğlu,
  • Sujit Pal and
  • Yunus Emre Türkmen

Beilstein J. Org. Chem. 2024, 20, 3290–3298, doi:10.3762/bjoc.20.273

Graphical Abstract
  • ) ligand 4 were reported by Cowley and co-workers in 2010 [14]. In addition to heterocyclic fluoranthene analogues, highly oxygenated benzo[j]fluoranthenes are commonly encountered fungal natural products with important biological activities [15]. Bulgarein (5) is an example of such a benzo[j]fluoranthene
  • ][27], as well as Friedel–Crafts [28] and Prins-type [29] reactions have been developed to date [2]. However, methods that enable access to the analogous acenaphthylene-fused heteroarenes are less common [30][31][32][33][34][35][36][37][38][39]. In one such study, Würthner and co-workers reported a Pd
  • -catalyzed annulation reaction between bromo-chloronaphthalene dicarboximides 6 and heteroarylboronic esters that enabled the syntheses of acenaphthylene-fused thiophene and indole derivatives 7 having donor-acceptor units (Scheme 1a) [40]. In 2021, Jin and co-workers developed an elegant Pd-catalyzed
PDF
Album
Supp Info
Full Research Paper
Published 23 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
  • first report from Zhdankin and co-workers in 1994, described the preparation of azidobenziodoxolone, ABX (I), a reagent widely used in oxidative azide transfer reactions [21]. Years later, Zhdankin’s group also reported the synthesis of amidobenziodoxolone (II) [14]. Other examples of N-containing
  • benziodoxol(on)es can be found in the literature, including reagents featuring cyclic aliphatic amine moieties (III) [15], phthalimidates (IV) [16], and carbazoles (VII) [19]. Minakata and co-workers proposed an innovative approach for transferring imine groups using iodane-containing (diarylmethylene)amino
  • )benziodoxolones (BBXs) 2 with ORTEP-3 diagram of compound 2d, using 50% probability level ellipsoids. One co-crystallized water molecule was omitted for clarity. CCDC 2368436 contains the supporting crystallographic data for this paper. Scope of the different β-sulfinyl esters 4 [32][33]. Isolated yields. rt
PDF
Album
Supp Info
Full Research Paper
Published 19 Dec 2024

Giese-type alkylation of dehydroalanine derivatives via silane-mediated alkyl bromide activation

  • Perry van der Heide,
  • Michele Retini,
  • Fabiola Fanini,
  • Giovanni Piersanti,
  • Francesco Secci,
  • Daniele Mazzarella,
  • Timothy Noël and
  • Alberto Luridiana

Beilstein J. Org. Chem. 2024, 20, 3274–3280, doi:10.3762/bjoc.20.271

Graphical Abstract
  • Center (CeSAR)-UniCA for the analysis service. Funding P. H. thanks the Erasmus+ traineeship program. The research contract (63-G-19602-1) of M.R. is co-financed by the European Union "FSE-REACT-EU, PON Research and innovation 2014-2020 DM 1062/2021" (CUP H31B21009610007). A.L. thanks the MUR for a Young
PDF
Album
Supp Info
Letter
Published 17 Dec 2024

Intramolecular C–H arylation of pyridine derivatives with a palladium catalyst for the synthesis of multiply fused heteroaromatic compounds

  • Yuki Nakanishi,
  • Shoichi Sugita,
  • Kentaro Okano and
  • Atsunori Mori

Beilstein J. Org. Chem. 2024, 20, 3256–3262, doi:10.3762/bjoc.20.269

Graphical Abstract
  • extraction was found despite the similarities in the lanthanide series [23]. Chakravorty and co-workers reported that a similar arylation reaction gave access to the fused skeleton of the diamide of 2,6-pyridinedicarboxlic acid (Py-2,6-diamide) [29]. Our interest has thus turned to extend the substrate scope
  • improved the yield to 77%. Chakravorty and co-workers showed that a smooth reaction proceeded with pyridine 2,6-dicarboxylic acid bisamide 3 [29] and we thus compared the reaction of 3 under similar conditions to that of 1a. The reaction afforded product 4 in 87% yield, which was found to be comparable
PDF
Album
Supp Info
Full Research Paper
Published 13 Dec 2024

Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

  • Sergio Torres-Oya and
  • Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

Graphical Abstract
  • carbamate group by interaction with the oxygen atom of the phosphoryl group. Although recently Rana and co-workers published a review article covering catalytic asymmetric transformations of azadienes [16], there is still room for this review which only focuses on non-covalent organocatalyzed cyclizations
  • their structure will be described. In 2012, Wang and co-workers reported a bifunctional thiourea-catalyzed aza-Diels–Alder reaction of cyclic keto/enolate salts 1 and N-tosyl-2-methylene-but-3-enoates 2 (Scheme 1). After a screening of the reaction conditions they found that organocatalyst I, acetic
  • organocatalyst acts as a Lewis base forming an enamine which raises the HOMO energy of the dienophile, while the thiourea moiety acts as a Lewis acid, lowering the LUMO level of the diene (Scheme 1). A confined transition state is formed providing a high enantiocontrol of the reaction. In 2016, Shi and co
PDF
Album
Review
Published 10 Dec 2024

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

  • Shin-ichiro Kurimoto,
  • Kouta Inoue,
  • Taito Ohno and
  • Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

Graphical Abstract
  • of psammaplysin A remained ambiguous for approximately 30 years but was determined in 2015 by Kurtán, Garson, and co-workers through a comparison of experimental and calculated electronic circular dichroism data, as well as a method employing Trost's chiral anisotropic reagents [6]. More recently
  • [25][26][27][28]. It is known that natural nitrile compounds are biosynthesized through various mechanisms [29]. Rinehart and co-workers demonstrated that 2-(3,5-dibromo-4-hydroxyphenyl)acetonitrile is biosynthesized from ʟ-tyrosine via 3,5-dibromo-ʟ-tyrosine, based on experiments using 14C- and 15N
  • a rare nitrile that contains a cyano group as aminoacetonitrile. The biosynthesis of the 8,10-dibromo-9-methoxy-1,6-dioxa-2-azaspiro[4.6]undeca-2,7,9-trien-4-ol scaffold has been proposed by Scheuer, Clardy and co-workers [5], but how the cyano group in 1 is biosynthesized remains unknown and is of
PDF
Album
Supp Info
Full Research Paper
Published 09 Dec 2024

Germanyl triazoles as a platform for CuAAC diversification and chemoselective orthogonal cross-coupling

  • John M. Halford-McGuff,
  • Thomas M. Richardson,
  • Aidan P. McKay,
  • Frederik Peschke,
  • Glenn A. Burley and
  • Allan J. B. Watson

Beilstein J. Org. Chem. 2024, 20, 3198–3204, doi:10.3762/bjoc.20.265

Graphical Abstract
  • cross-couplings. Schoenebeck and co-workers have shown that Ge-based compounds are versatile reagents within chemoselective cross-coupling processes for the formation of a variety of C–C and C–X bonds [55][56][57][58][59][60][61][62][63]. Importantly, these transformations can take place in the presence
  • potential as functional handles for downstream elaboration of CuAAC products. To date, the main use of germanyl alkynes in (3 + 2) cycloadditions has been limited to a small number of Huisgen (non-Cu-catalysed) reactions [68][69]. Zaitsev and co-workers reported the synthesis and CuAAC reactions of a
  • ]. Similarly, cross-coupling of the GeEt3 moiety in 15 under conditions developed by Schoenebeck and co-workers gave 29 [57]. Bromodegermanylation using NBS employing conditions from Schoenebeck gave bromotriazoles 30 and 31 in moderate to excellent yield [62]. These could then undergo Suzuki–Miyaura cross
PDF
Album
Supp Info
Full Research Paper
Published 05 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
  • isomers, two due to the E and Z isomers of the imine group (–N=CH–) and two due to the syn/anti-conformers of the amide bond (–NH-CO–). Experimentally, the E isomer is often more stable and so, predominant. The strong correlation between the NH and CH of the imine observed in 2D 1H-1H NOE experiments for
  • Supporting Information File 30: Experimental procedures, product characterization, X-ray analysis and copies of NMR spectra. Acknowledgements The authors gratefully acknowledge Central Glass Co. for the gift of trifluoro- and difluoroacetaldehyde hemiacetal.
PDF
Album
Supp Info
Full Research Paper
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
  • eliminated through microwave-assisted treatment under acidic conditions, resulting in the intramolecular cyclization of the amine onto the ketone derived from glyoxaldehyde (Scheme 14). Vézina-Dawod and co-workers [60] introduced a strategy, which consists of two reactions, for synthesizing highly
PDF
Album
Review
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
  • carbocycles can be synthesized mildly and effectively using HVI reagents. Nitrogen nucleophiles A metal-free synthesis of β-fluorinated piperidines was reported in 2012 by Meng, Li and co-workers (Scheme 1) [26]. The authors describe a reaction using PhI(OPiv)2 as oxidant with HF·pyridine as the source of
  • products or stabilised by the tosyl group and subsequently attacked to form only the cis product in an SN2 reaction. Liu and co-workers reported a palladium-catalysed intramolecular aminofluorination of unactivated alkenes [27] (Scheme 2) in the presence of PhI(OPiv)2, AgF and MgSO4 as an oxidant, source
  • , was not ruled out. In 2013, Nevado and co-workers used (R,R)- and (S,S)-tert-butyl lactate iodotoluene difluoride (8) for the aminofluorination of alkenes toward the synthesis of enantiomerically pure β-fluorinated piperidines 6 (Scheme 3) [28]. A range of enantiomerically pure fluorinated piperidines
PDF
Album
Review
Published 28 Nov 2024

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

  • Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

Graphical Abstract
  • solutions [18]. Similarly, Burns and co-workers reported di- and tetra-urea picket porphyrins highlighting, the impact of buried solvent molecules, such as DMSO, on the selectivity, affinity, and stoichiometry of anion binding [19]. Iron complexes of tetra-urea picket porphyrins further demonstrate how
  • -defined binding pockets, offer a preorganized arrangement of functional groups as a suitable microenvironment for organocatalysis. In 2008, Kohnke, Soriente and co-workers first reported [37] the H-bonding organocatalytic activity of calix[4]pyrrole derivatives 3 and 4 and acyclic dipyrromethane 5 for the
  • /16) aldol products with up to 82% yield in a 70:30 diastereoisomeric ratio. A decade after, Ema, Maeda and co-workers investigated using of calix[4]pyrrole macrocyclic organocatalysts for the synthesis of cyclic carbonates 21 from epoxides 20 (1,2-epoxyhexane) and CO2 [39]. For this purpose, they
PDF
Album
Review
Published 27 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
  • to obtain the 1,5-disubstituted tetrazole-alkyne 19 is well-documented and hence, it is not herein described in detail [1][26][31]. Thus, based on Pal and co-workers’ proposal [32][33], the second process involves two catalytic cycles: 1) a Sonogashira coupling, and 2) a 5-endo-dig cyclization. The
PDF
Album
Supp Info
Full Research Paper
Published 26 Nov 2024

Enantioselective regiospecific addition of propargyltrichlorosilane to aldehydes catalyzed by biisoquinoline N,N’-dioxide

  • Noble Brako,
  • Sreerag Moorkkannur Narayanan,
  • Amber Burns,
  • Layla Auter,
  • Valentino Cesiliano,
  • Rajeev Prabhakar and
  • Norito Takenaka

Beilstein J. Org. Chem. 2024, 20, 3069–3076, doi:10.3762/bjoc.20.255

Graphical Abstract
  • study, Hoveyda and co-workers proposed a similar mechanism for the isomerization of alkynes to allenes catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene [61]. Conclusion In this study, we prepared distilled propargyltrichlorosilane with >99% isomeric purity for the first time, developed its asymmetric
PDF
Album
Supp Info
Letter
Published 25 Nov 2024

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

  • Thomas Ma and
  • John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

Graphical Abstract
  • recognizes and activates a specific substrate BB. Notably, the BBs are in most cases amino acids, wherein a much broader variety are used in NRP biosynthesis than the 20 canonical amino acids used in protein biosynthesis [52]. The modules are usually arranged co-linearly to the BGC sequence, which makes
  • molecules Aside from an analysis of the BB usage pattern, real NRP-like molecules can be constructed in accordance to the predicted identity and order of the BBs. Brady and co-workers used solid-phase peptide synthesis to convert the predicted NRPs from virtual into reality; they called these molecules
  • properties. Specifically, Qian and co-workers examined 7395 bacterial genomes and identified more than ten thousand potential cationic NRPs. They focused on a few promising candidates after bioinformatic-based dereplication and found two NRPs, brevicidine and laterocidine, that worked in an animal thigh
PDF
Album
Perspective
Published 20 Nov 2024
Graphical Abstract
  • conventional synthesis. A similar [2]rotaxane molecule bearing a Co complex exhibited ICD derived from the chirality of CD on the absorption band of the cobalt complex [37]. Afterward, numerous CD-based rotaxane syntheses were reported; they generally contained noncovalent-bond moieties on the dumbbell
  • structure in the early days. Rotaxane bearing a dumbbell comprising only covalent bonds was first reported by Harada and co-workers in 1997 (Scheme 1B) [38]. In this system, the end-capping reaction was based on the nucleophilic substitution of the amino groups on the axle ends. Afterward, such nucleophilic
  • synthesize the rotaxane. For example, Anderson and co-workers reported the synthesis of γ-CD–based [2]rotaxane via the Suzuki reaction using a dicarboxylic acid end-capping reagent; they reported a 17% yield (Scheme 1C) [39]. To perform an end-capping reaction in water, multiple hydrophilic substituents
PDF
Album
Review
Published 19 Nov 2024

Advances in radical peroxidation with hydroperoxides

  • Oleg V. Bityukov,
  • Pavel Yu. Serdyuchenko,
  • Andrey S. Kirillov,
  • Gennady I. Nikishin,
  • Vera A. Vil’ and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

Graphical Abstract
  • colleagues firstly demonstrated that the decomposition of tert-butyl hydroperoxide (TBHP) by Co(II) naphthenate proceeds via a chain mechanism, leading to the formation of tert-butoxy and tert-butylperoxy radicals (Scheme 4) [24]. When cyclohexene (1) and oct-1-ene (3) were added, the corresponding products
  • of allylic peroxidation 2, 4 and 5 were observed (Scheme 4) [24]. Similar transformations were reported later using CuCl as the catalyst [39]. Later, Gade with coauthors demonstrated the allylic peroxidation of cyclohexane with TBHP using the alkylperoxocobalt(III) complexes [Co(BPI)(OAc)(OO-t-Bu
  • Cu(II) salt. The cobalt-catalyzed peroxidation of cyclic compounds 21 by TBHP has been demonstrated (Scheme 11) [48]. There are three possible reaction pathways: the first starts with the oxidation of cobalt(II) by TBHP to form cobalt(III) and the tert-butoxy radical (step A). Next, the formed Co(III
PDF
Album
Review
Published 18 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
  • 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
  • easily recycled just by washing it with ethanol, retaining its catalytic activity for arylation up to three cycles without any compromise. Thus, this procedure could be considered economic as well as environment-friendly. In 2019, Kalek and co-workers reported the regioselective C–H arylation of 2
  • products. The radical path was considered for the reaction mechanism as on adding TEMPO as radical scavenger the radical trapping adduct was detected by HRMS. Simultaneously with the above work, Murarka and co-workers also reported an organophotoredox-catalyzed stereoselective allylic arylation method for
PDF
Album
Review
Published 13 Nov 2024
Other Beilstein-Institut Open Science Activities