Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• systems can function as both photooxidants and photoreductants, engaging in either energy-transfer or electron-transfer processes with high efficiency [40]. Notably, D. Gryko et al. demonstrated their application in activating diazoalkanes through red-light-mediated photosensitization and photoredox

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

• [3 + 2] cycloaddition reaction between azodicarboxylates and nitrile ylides XXXVI as 1,3-dipoles. The latter are generated from diazoalkanes under the coordination of the copper catalyst to form a carbenoid species that undergoes nucleophilic attack of the nitriles. This transformation has

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

CF₃-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

• Anthony J. Fernandes,
• Armen Panossian,
• Bastien Michelet,
• Agnès Martin-Mingot,
• Frédéric R. Leroux and
• Sébastien Thibaudeau

Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32

Hydrolysis, polarity, and conformational impact of C-terminal partially fluorinated ethyl esters in peptide models

• Vladimir Kubyshkin and
• Nediljko Budisa

Beilstein J. Org. Chem. 2017, 13, 2442–2457, doi:10.3762/bjoc.13.241

• incorporation of a fluorinated moiety into a modular peptide fragment is highly desirable. Several recent efforts have been made to achieve this goal [9][47]. Fluorinated diazoalkanes have shown particularly promising results in small molecule functionalization [48], and these have a potential to be used for

• chloride (0.1 mL, 1.4 mmol, 2.2 equiv) and trifluoroethanol (0.12 mL, 1.6 mmol, 2.5 equiv). 141 mg of the product was obtained as a clear oil (yield 93%), Rf = 0.73 (ethyl acetate/methanol 39:1). Esterification with diazoalkanes No special precautions were applied when working with 2,2-difluorodiazoethane

Three-component synthesis of highly functionalized aziridines containing a peptide side chain and their one-step transformation into β-functionalized α-ketoamides

• Lena Huck,
• Juan F. González,
• Elena de la Cuesta and
• J. Carlos Menéndez

Beilstein J. Org. Chem. 2016, 12, 1772–1777, doi:10.3762/bjoc.12.166

• direct aziridination of an olefin [14] or the reaction of an imine with diazoalkanes. Alternatively, the reaction of imines with various nucleophiles, including aza-Darzens mechanisms, can lead to aziridine products [15]. However, few known methods allow the synthesis of C-trisubstituted aziridines

Diradical reaction mechanisms in [3 + 2]-cycloadditions of hetaryl thioketones with alkyl- or trimethylsilyl-substituted diazomethanes

• Grzegorz Mlostoń,
• Paulina Pipiak and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 716–724, doi:10.3762/bjoc.12.71

• . Remarkably, in no single case, the ‘head-to-head dimerization’ of aryl/hetaryl and dihetaryl substituted thiocarbonyl ylides was observed. Keywords: [3 + 2]-cycloadditions; diazoalkanes; diradicals; 1,3-dithiolanes; reaction mechanisms; thioketones; Introduction Cycloaddition reactions belong to the most

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation

• Andrey S. Mereshchenko,
• Alexey V. Ivanov,
• Viktor I. Baranovskii,
• Grzegorz Mloston,
• Ludmila L. Rodina and
• Valerij A. Nikolaev

Beilstein J. Org. Chem. 2015, 11, 504–513, doi:10.3762/bjoc.11.57

• of a wide variety of nitrogen containing heterocyclic compounds [1][2][3][4][5]. These reactions are generally known for diazoalkanes and 2-diazocarbonyl compounds, whereas similar processes with 2-diazo-1,3-dicarbonyl compounds (DDC) are far less common [6][7][8][9][10], and reported literature data

Three-component synthesis of C₂F₅-substituted pyrazoles from C₂F₅CH₂NH₂·HCl, NaNO₂ and electron-deficient alkynes

• Pavel K. Mykhailiuk

Beilstein J. Org. Chem. 2015, 11, 16–24, doi:10.3762/bjoc.11.3

• CF3CHN2. On the other hand, C2F5 and CF3 groups have similar electron-withdrawing abilities [1], and hence the both diazoalkanes might have similar reactivities. In reality, under the same conditions, after seven days at room temperature alkyne 19 reacted with CF3CHN2 completely, while the corresponding

Less reactive dipoles of diazodicarbonyl compounds in reaction with cycloaliphatic thioketones – First evidence for the 1,3-oxathiole–thiocarbonyl ylide interconversion

• Valerij A. Nikolaev,
• Alexey V. Ivanov,
• Ludmila L. Rodina and
• Grzegorz Mlostoń

Beilstein J. Org. Chem. 2013, 9, 2751–2761, doi:10.3762/bjoc.9.309

• diazoalkanes, diazoesters and diazoketones [1][2][3][4]. Due to their high dipolarophilic reactivity thioketones were given the name ‘superdipolarophiles’ [3][4]. It might be expected that these highly reactive dipolarophiles could also easily react with the deactivated 1,3-dipoles of 2-diazo-1,3-dicarbonyl

Dipolar addition to cyclic vinyl sulfones leading to dual conformation tricycles

• Steven S. Y. Wong,
• Michael G. Brant,
• Christopher Barr,
• Allen G. Oliver and
• Jeremy E. Wulff

Beilstein J. Org. Chem. 2013, 9, 1419–1425, doi:10.3762/bjoc.9.159

• expedient regio- and stereospecific synthesis of five-membered ring N-, O- or S-containing heterocycles [4][5]. Various 1,3-dipoles can be used, including nitrones [6], azomethine ylides [7], diazoalkanes [8][9] and many others [10][11][12]. α,β-Unsaturated carbonyl compounds are often found to be good

Diels- Alder reactions using 4,7-dioxygenated indanones as dienophiles for regioselective construction of oxygenated 2,3-dihydrobenz[f]indenone skeleton

• Natsuno Etomi,
• Takuya Kumamoto,
• Waka Nakanishi and
• Tsutomu Ishikawa

Beilstein J. Org. Chem. 2008, 4, No. 15, doi:10.3762/bjoc.4.15

• compounds had been originally characterized as cyanamides 1 with a linearly-fused 6-6-5-6 membered ring system [11][12]; however, the structure was revised to diazoalkanes 2 by spectroscopic means [13][14] and by total synthesis [15][16][17] (Figure 1). In our total synthesis of methyl-kinamycin C (3) [21