Search results

Search for "cycloadditions" in Full Text gives 247 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones

  • Grzegorz Mlostoń,
  • Małgorzata Celeda,
  • Marcin Palusiak,
  • Heinz Heimgartner,
  • Marta Denel-Bobrowska and
  • Agnieszka B. Olejniczak

Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113

Graphical Abstract
  • derived from 5-mercapto-1H-tetrazoles was also examined. Keywords: 2,5-dihydro-1,3,4-thiadiazoles; enolizable 5-mercapto-1H-tetrazoles; insertion reactions; thiiranes; thiocarbonyl ylides; X-ray analysis; Introduction Cycloaddition reactions, including 1,3-dipolar cycloadditions, are considered as one
  • of the most important types of organic reactions with key importance for the development of methods of modern organic synthesis [1][2][3]. Therefore, conversions of 1,3-dipoles which cover not only cycloadditions but also annulation and insertion reaction attract great attention worldwide [2][3][4
  • five-membered heterocycles via [3 + 2]-cycloaddition reactions. Depending on the type of the dipolarophile used in these reactions, the target heterocycles may contain only one sulfur atom (cycloadditions with C=C or C≡C dipolarophiles) or more heteroatoms (cycloadditions with C=S, C=O, C=N, N=N, S=O
PDF
Album
Supp Info
Full Research Paper
Published 23 Jul 2025

Copper catalysis: a constantly evolving field

  • Elena Fernández and
  • Jaesook Yun

Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109

Graphical Abstract
  • reactions, are separately debated. In addition, mechanistic insights into the reaction of heteropolycyclic systems, cycloadditions, and aza-Diels–Alder reactions are provided. This is important because multicomponent, one-pot reactions have gained interest as potentially more economic, efficient, and
PDF
Editorial
Published 17 Jul 2025

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

  • Meng Qiu,
  • Jing Du,
  • Nai-Te Yao,
  • Xin-Yue Wang and
  • Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

Graphical Abstract
  • 6 exhibiting enhanced chiroptical performance and protonation-induced CPL amplification [19]. Meanwhile, Audisio’s team developed heterohelicenes via regioselective [3 + 2]-cycloadditions, with compound 7 displaying pH-responsive CPL sign inversion (|glum| = +1.1 × 10−3 at 430 nm, −1.2 × 10−3 at 585
PDF
Album
Review
Published 11 Jul 2025

Oxetanes: formation, reactivity and total syntheses of natural products

  • Peter Gabko,
  • Martin Kalník and
  • Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

Graphical Abstract
  • 2016 complemented by a few older works that were deemed powerful and relevant for illustrating a given reaction mode. Chapter 1 covers strategies for the oxetane ring formation including substitutions, cycloadditions, ring-size manipulations and carbene insertions. Chapter 2 details chemical
  • categorised into 6 synthetic strategies as depicted in Scheme 1: a) C–O bond-forming cyclisations, b) C–C bond-forming cyclisations, c) [2 + 2] cycloadditions between carbonyls and alkenes, d) ring expansions, e) ring contractions and f) O–H insertions. In the following subchapters, these strategies will be
  • -, particularly 2-methylideneoxetanes have become valuable intermediates in oxetane chemistry as they readily undergo a variety of chemical transformations, including ring-opening reactions with nucleophiles, epoxidations, cyclopropanations and [3 + 2] cycloadditions with nitrile oxides [51][52]. In addition
PDF
Album
Review
Published 27 Jun 2025

A multicomponent reaction-initiated synthesis of imidazopyridine-fused isoquinolinones

  • Ashutosh Nath,
  • John Mark Awad and
  • Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 1161–1169, doi:10.3762/bjoc.21.92

Graphical Abstract
  • for all substitutes of 6a, 6h, 6r and 6j, which, are not ideal effective for IMDA cycloadditions compared to the other substitute cycloadditions. The R2 substituent on the imidazopyridine moiety in 6 was found to have a significant electronic impact on the IMDA cycloaddition. When R2 is a halogen (Br
PDF
Album
Supp Info
Full Research Paper
Published 13 Jun 2025

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

  • Chun-Yu Mi,
  • Jia-Yuan Zhai and
  • Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

Graphical Abstract
  • have attracted considerable attention due to their promise in the total synthesis of alkaloids [16]. Notably, these valuable compounds can be employed as efficient synthons in enamide–alkyne cycloisomerization, [n + m] cycloadditions, pericyclic reactions, and radical cyclizations. A comprehensive
  • (−)-dihydrolycopodine, (−)-lycopodine, (+)-lycoposerramine Q, (+)-fawcettidine, (+)-fawcettimine, and (−)-phlegmariurine have been synthesized in a concise and efficient manner, while employment of the [2 + 3] cycloadditions or a polycyclization enables the elegant total synthesis of Cephalotaxus alkaloids
PDF
Album
Review
Published 22 May 2025

Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

  • Lewis McGhie,
  • Hannah M. Kortman,
  • Jenna Rumpf,
  • Peter H. Seeberger and
  • John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

Graphical Abstract
  • facilitated landmark organic transformations, such as the venerable Paternò–Büchi [6][7][8], Norrish–Yang [9][10][11], and enone–alkene cycloadditions [12][13][14], that proceed via the generation of a singlet or triplet diradical through the activation of an unsaturated bond [2][14]. While these seminal
  • isomerization of alkenes [18][19], [2 + 2] cycloadditions [20][21][22][23][24], and dearomative [4 + 2] cycloadditions [25][26][27]. When considering conjugated alkenes, the triplet excited state energy and excited state lifetime are intrinsically linked to the degree of conjugation and substitution of a
PDF
Album
Supp Info
Letter
Published 30 Apr 2025

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

  • Francesco Mele,
  • Ana M. Constantin,
  • Andrea Porcheddu,
  • Raimondo Maggi,
  • Giovanni Maestri,
  • Nicola Della Ca’ and
  • Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

Graphical Abstract
  • comes with higher costs, more complex operation, and challenges in effectively integrating light sources for photomechanochemical reactions. Manual grinding Manual grinding was predominantly used in the early days of photomechanochemistry, when [2 + 2] photochemical cycloadditions were extensively
  • enhancement of photocatalyzed [2 + 2] cycloadditions under aerobic conditions, even though over longer irradiation times the solution-state yields are superior (Scheme 11D). Very recently, Wu, Wang, and co-workers proposed a radically different approach to photomechanochemistry [78]. Rather than trying to
PDF
Album
Perspective
Published 03 Mar 2025

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
  • -based natural product, which was discovered to induce topoisomerase I-mediated DNA cleavage [16][17]. For the construction of the fluoranthene skeleton, a broad range of synthetic strategies including C–H arylation [18][19][20][21][22], Diels–Alder [7][8][23][24][25] and [2 + 2 + 2] cycloadditions [26
PDF
Album
Supp Info
Full Research Paper
Published 23 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
  • methodologies of 1-azadienes involve a formal [4 + 2] cycloaddition (IEDADA reaction) to construct six-membered nitrogen-containing molecules, α,β-unsaturated imines can also behave as C4 synthons involved in (4 + 1) and (4 + 3) cycloadditions or they act as C2 synthons undergoing (2 + 3) cycloadditions for
PDF
Album
Review
Published 10 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
  • 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
PDF
Album
Supp Info
Full Research Paper
Published 05 Dec 2024

Mechanochemical difluoromethylations of ketones

  • Jinbo Ke,
  • Pit van Bonn and
  • Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

Graphical Abstract
  • and 1n were studied. Both gave the expected products in yields of 50% (for 3m) and 44% (for 3n). Besides these successful transformations several ketones proved unsuitable (Scheme S1 in Supporting Information File 1). Additionally, attempted [4 + 1]-type cycloadditions of three 1-arylprop-2-en-1-ones
PDF
Album
Supp Info
Letter
Published 04 Nov 2024

Copper-catalyzed yne-allylic substitutions: concept and recent developments

  • Shuang Yang and
  • Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

Graphical Abstract
  • ethynylethylene carbonates as the starting materials, thus completing their enantioselective formal [4 + 1] cycloadditions with cyclic 1,3-dicarbonyl compounds (Scheme 36, 34a–k). They speculated that in the reaction mechanism, the key step is the formation of the copper vinyl allenylidene intermediate from vinyl
PDF
Album
Review
Published 31 Oct 2024

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

  • Ignaz Betcke,
  • Alissa C. Götzinger,
  • Maryna M. Kornet and
  • Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

Graphical Abstract
  • were overcome by the addition–cyclocondensation of α,β-unsaturated ketones. Embedding 1,3-dipolar cycloadditions into a one-pot process has additionally been developed for concise syntheses of pyrazoles. The MCR strategy also allows for concatenating classical condensation-based methodology with modern
  • with electrophiles, such as deuteration or electrophilic chlorination using N-chlorosuccinimide, in this consecutive three-component synthesis to give persubstituted pyrazoles 165 (Scheme 55) [162]. (3 + 2)-Cycloaddition – C2 building blocks as substrates 1,3-Dipolar cycloadditions are important
  • ) cycloadditions with alkenes or alkynes to form pyrazoles, also in the sense of MCR. Furthermore, while not strictly classified as pericyclic reactions, hydrazones are also recognized as CN2 building blocks in pyrazole synthesis [169]. 1,3-Dipoles as key intermediates Various methods have been developed for the
PDF
Album
Review
Published 16 Aug 2024

Syntheses and medicinal chemistry of spiro heterocyclic steroids

  • Laura L. Romero-Hernández,
  • Ana Isabel Ahuja-Casarín,
  • Penélope Merino-Montiel,
  • Sara Montiel-Smith,
  • José Luis Vega-Báez and
  • Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

Graphical Abstract
  • decarboxylation of the carboxylic residue when heated at reflux of methanol. After the regioselective cycloadditions, spiro compounds 49a,b were obtained in yields ranging from 75% to 91% (Scheme 15). Related derivatives have similarly been achieved in good to excellent yields [32][33]. Recently, López et al
PDF
Album
Review
Published 24 Jul 2024

A fiber-optic spectroscopic setup for isomerization quantum yield determination

  • Anouk Volker,
  • Jorn D. Steen and
  • Stefano Crespi

Beilstein J. Org. Chem. 2024, 20, 1684–1692, doi:10.3762/bjoc.20.150

Graphical Abstract
  • reactant. This isomerization can be reversed by light of a different wavelength or thermal stimuli. Depending on the nature of the reactant, different classes of photoreactions can be utilized: double bond isomerizations, electrocyclization, cycloadditions, and electron-, hydrogen-, or group transfer [1
PDF
Album
Supp Info
Full Research Paper
Published 22 Jul 2024

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

  • Christopher Mairhofer,
  • David Naderer and
  • Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

Graphical Abstract
  • ][10][11][12][13][14]. For example, such molecules can be utilized to access free amines [3][13] and undergo Staudinger-type ligations [14]. Furthermore, they can be very efficiently employed for triazole-forming 1,3-dipolar cycloadditions with alkynes (“click-chemistry”) [9][10][11][12]. As a
PDF
Album
Supp Info
Full Research Paper
Published 05 Jul 2024

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

Graphical Abstract
  • vinyl propargylic esters could be employed as five-carbon atom building blocks in [5 + 2] cycloadditions with alkynes or alkenes by carbene intermediates. Starting from those results they envisaged the benzannulation of heteroaryl propargylic esters favored by CO [44]. The process led to the desired
PDF
Album
Review
Published 30 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
  • were rare, but a number of practical approaches have been disclosed in recent years. Many of these utilise the ability of bicyclo[1.1.0]butanes (BCBs) to undergo [2σ-2π]-type cycloadditions with alkene reaction partners [37]. Brown and co-workers used this approach to synthesise a variety of 1,2-BCHs
  • catalytic system of B2cat2 and 4-phenylpyridine to form pyridine-boryl radicals which initiated ring expansion. The method was shown to be similarly tolerable of functional groups as Procter’s synthesis. Intramolecular crossed [2 + 2] cycloadditions offer an alternative approach to 1,2-disubstituted BCHs
PDF
Album
Review
Published 19 Apr 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
  • purification by column chromatography prior to their on-surface deposition. By way of example, the synthesis of decacene precursor 59 was achieved in three synthetic steps by iterative [4 + 2] cycloadditions with an overall yield of 4.7% (Scheme 17). The synthesis of epoxyacene 59 started with the mono-Diels
PDF
Album
Review
Published 15 Feb 2024

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

Graphical Abstract
  • opening. Keywords: cycloadditions; DFT calculations; [70]fullerene; open-cage fullerenes; rhodium; Introduction The discovery of C60 (buckminsterfullerene) in 1985 [1] initiated the search for possible technological applications of fullerenes. Nowadays, applications for these carbon-based molecules have
  • medical applications) and improving their stability, among other desirable properties. The most common reactions used to functionalize fullerenes are Diels–Alder and 1,3-dipolar cycloadditions and Bingel–Hirsch cyclopropanations [19][20]. In most cases, functionalization occurs while preserving the carbon
PDF
Album
Supp Info
Full Research Paper
Published 13 Feb 2024

Catalytic multi-step domino and one-pot reactions

  • Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

Graphical Abstract
  • of transannular cycloadditions of cycloalkenone hydrazones catalyzed by BINOL-derived phosphoric acid are reported in the Full Research Paper by Vicario, Merino, and co-workers [10]. Their methodologies can now be used to predict the reactivity of different substrates in other cycloaddition reactions
PDF
Album
Editorial
Published 08 Feb 2024

Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations

  • Laura Abella,
  • Gerard Novell-Leruth,
  • Josep M. Ricart,
  • Josep M. Poblet and
  • Antonio Rodríguez-Fortea

Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10

Graphical Abstract
  • the dimerization of two neutral C60 molecules were also computed for comparison (Table 1). As products, we have considered dimer 1-D2h and dimer 1-Cs, which are products of reversible [2 + 2] cycloadditions (phase 1) between two [6,6]-bonds in the former case and, between a [6,6]-bond and a [6,5]-bond
PDF
Album
Supp Info
Full Research Paper
Published 17 Jan 2024

Biphenylene-containing polycyclic conjugated compounds

  • Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

Graphical Abstract
  • cycloadditions from bay regions of [N]phenylenes, metal-catalyzed cycloadditions with diphenylacetylene occurred exclusively in the non-bay region, which allowed for straightforward syntheses of curved structures. Moreover, the presence of methyl groups in the structure facilitated the controlled activation of
  • via [2 + 2] and [2 + 2 + 2] cycloadditions. In a closely related study conducted by Grill et al., the behavior of 2,3-dibromoanthracene (89) was examined on two distinct surfaces [Au(100) and Au(111)] (Scheme 19) [52]. Notably, on the Au(111) substrate, nearly equivalent quantities of dimer 91
PDF
Album
Review
Published 13 Dec 2023

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

Graphical Abstract
  • organocatalysts is well-established in several organic reactions, including but not limited to aldol reactions [6], Michael additions [9], Mannich reactions [10], aza-Henry reactions [11], and Diels–Alder cycloadditions [12][13]. Although the benefits of organocatalysts are undoubted, their synthesis is often a
PDF
Album
Supp Info
Full Research Paper
Published 24 Nov 2023
Other Beilstein-Institut Open Science Activities