Synthesis and photoinduced switching properties of C₇-heteroatom containing push–pull norbornadiene derivatives

• Daniel Krappmann and
• Andreas Hirsch

Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64

• signal in the range of 6.15–5.90 ppm. However, due to the lack of new formed aliphatic signals, and in comparison to literature [35], formation of N-QC1 is very unlikely. Furthermore, additional signals in the region below 2.0 ppm indicate the formation of decomposition products. Studies conducted by

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• , or phenyl groups at the α-position. The researchers noted that the lower yields were due to substrate decomposition or poor conversion rather than regioselectivity issues. Additionally, this method was also suitable for the phosphorylation of ferrocenes. For mechanistic studies, the reaction was

• decomposition leads to the generation of O₂, the primary oxygen source in the reaction process. A radical process was proposed in the reaction. Diphenylphosphine oxide and carbazole radicals were formed via anodic oxidation in the presence of a base, followed by a coupling reaction to give the final P–N product

• . Changing the electric current intensity reduced the yield, and using dry acetonitrile also led to a significant decrease in yield. These results indicate that water undergoes decomposition in the reaction, generating oxygen as the primary oxygen source in the system. The reaction proceeded via the anodic

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• formaldehyde and ammonia in situ by heating [83]. Under these conditions, the water present in hydrated HMTA is sufficient for this hydrothermal decomposition to occur. On the other hand, an excess of ammonia must be added to the reaction mixture to shift the equilibrium towards the imine. Using this procedure

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• achieved due to chemical modification of ANTH [25][32]. Changes in the UV–vis spectra were typically used as an indication of the compounds’ decomposition. It is well established that ANTH is rapidly oxidized to form anthraquinone upon exposure to light in the presence of oxygen. Furthermore, endoperoxides

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• ). However, reducing the concentration to 0.014 M increases the enantioselectivity (entries 6 and 7, Table 4), and an excellent enantiomeric ratio was maintained over time (entries 8 and 9, Table 4). These results suggest that at very dilute concentrations, the decomposition of the enantiomer (3R,4S)-1 is

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

• instead of 2 h in a row) proved beneficial to minimize heat accumulation resulting in product decomposition. Next, the authors proved the generality of mechanoluminescence by performing the sulfonylation of alkenes via EDA-complexes photochemistry (Scheme 12B). Thus, when a mixture of 1,1-diphenylethylene

Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• renders them particularly suitable for the generation of arynes for subsequent use in a wide range of synthetic applications. The common approach to generate cyclic biaryl λ3-bromanes is based on thermal decomposition of hazardous diazonium salts. Herein, we disclose a mild and straightforward approach to

• molecular nitrogen in diazonium compounds. Accordingly, pre-formed [12] or in situ-generated 2,2’-bromodiazonium salts 2 [11][13][14] furnish cyclic bromine(III) species 1 under thermal decomposition conditions (Scheme 1, reaction 1). The diazonium intermediates 2 are obtained by diazotation of 2'-bromo

• required thermal decomposition of the diazonium salt to effect the cyclization. In the quest for mild (room temperature) and scalable conditions toward cyclic diaryl λ3-bromanes 1 we realized that bromanyl units possess leaving group abilities comparable to the diazonium moiety [1][15]. Hence, the

Unraveling aromaticity: the dual worlds of pyrazole, pyrazoline, and 3D carborane

• Zahra Noori,
• Miquel Solà,
• Clara Viñas,
• Francesc Teixidor and
• Jordi Poater

Beilstein J. Org. Chem. 2025, 21, 412–420, doi:10.3762/bjoc.21.29

• a Kohn–Sham molecular orbital analysis together with an energy decomposition analysis (Figure S1 in Supporting Information File 1). To form the broken bonds, both fragments have two unpaired electrons (at their triplet state). The interaction between both fragments amounts to −227.9 kcal mol−1

• , the energy decomposition analysis has been performed at the ZORA-BLYP-D3(BJ)/TZ2P level of theory with AMS software [81][82][83][84]. Series o-carborane-fused pyrazoles under analysis. Bond lengths (in Å) of systems under analysis (top row) and reference systems (second and third rows) from the fusion

• clockwise/anticlockwise. Figure S3 in Supporting Information File 1 encloses the rest of the systems. Supporting Information Supporting Information File 22: Energy decomposition analysis of pyrazoleCC (fragments used, molecular orbitals overlaps, and fragment molecular orbitals), cartesian coordinates and

Identification and removal of a cryptic impurity in pomalidomide-PEG based PROTAC

• Bingnan Wang,
• Yong Lu and
• Chuo Chen

Beilstein J. Org. Chem. 2025, 21, 407–411, doi:10.3762/bjoc.21.28

• formed due to the decomposition of DMF. Whereas switching the solvent could prevent its formation, the accumulation of 7 remained an issue, giving no substantial improvement in the yield of 3 in, for example, NMP. In MeCN, glutarimide displacement became a major reaction. Because NMP was significantly

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

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

• sacrificial reducing agents (Scheme 6), contrasting with traditional blue-light photocatalysis which led to substrate decomposition [33][34]. The axial ligands on the ruthenium phthalocyanin complex, particularly electron-deficient pyridyl groups, were found to influence the catalytic activity by stabilizing

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

• electrophiles in various nucleophilic transformations due to their susceptibility to rapid decomposition into the corresponding isocyanates (Scheme 1a) [2][3]. They have attracted increasing interest as electrophilic amide sources in amidation using transition-metal catalysts such as ruthenium, rhodium, and

• functionalities were well tolerated in this transformation (26e–g). Moreover, an olefin-containing terminal alkyne was suitable to afford product 26h, demonstrating excellent chemoselectivity. However, the formation of 26i was not observed under the standard reaction conditions. Instead, the decomposition of

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

• , such as increasing the amount of DDQ or elevating the reaction temperature in the Scholl reaction of 10, only resulted in complex mixtures. Further attempts to subject 3 to the Scholl reaction conditions did not yield further cyclized products but led to the decomposition of the starting material

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

• the targeted benzo[j]fluoranthene product 32 was isolated in 45% yield. It should be noted that this reaction was not successful when an analogue of compound 31 with -OTIPS instead of the -OMOM group was tested as the boronic ester reaction partner, due to the decomposition of this compound presumably

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• gravimetric analysis (TGA) under a N2 atmosphere in the dynamic mode. The TGA curves (Figure S35 and Table S4 in Supporting Information File 1) show that all compounds undergo two thermal decomposition processes; an initial thermal event with a decomposition temperature (Tdec, at weight loss 5%) between 283

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

• , Tomilov et al. described the formation of tetrahydropyridazine 3,4,5,6-tetracarboxylic esters in 42% yield upon the decomposition in chloroform at 60 °C of methyl diazoacetate in the presence of pyridine and catalyzed by rhodium(II) acetate (Scheme 1b) [24][25]. More recently, an unusual [4 + 2

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

• Robin Schulte,
• Dustin Schade,
• Thomas Paululat,
• Till J. B. Zähringer,
• Christoph Kerzig and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

• spectra were observed. In the case of compounds 1j and 1n, the endpoint of the photoreaction could not be identified, as a steady decrease of the whole absorption spectra during irradiation indicated secondary decomposition reactions. We previously reported triplet energy transfer between 3[Ru(phen)3](PF6

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• to the VSC-based system, this crosslinker can be applied to various vinyl polymerizations, and the resulting RCP showed properties depending on the monomers used. Meanwhile, since the size-complementary framework was integrated with this crosslinker, heating induced the decomposition of the rotaxane

Tailored charge-neutral self-assembled L₂Zn₂ container for taming oxalate

• David Ocklenburg and
• David Van Craen

Beilstein J. Org. Chem. 2024, 20, 3007–3015, doi:10.3762/bjoc.20.250

• can easily replace ligand strands leading to a partial or full receptor decomposition. Herein, we present a charge-neutral zinc(II)-based metallocontainer which was tuned to contest oxalate as most competitive dicarboxylate. The dianion is bound in a 1:1 fashion with a binding constant of log K = 4.39

• limiting solubility. a) Generally desired guest recognition by encapsulation of the analyte within self-assembled metal-based containers or cages (left reaction). Often observed challenge with very competitive anionic guests which tend to result in decomposition of the initial receptor structure (right

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

• 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

• product 32 formation is similar to the metal-catalyzed peroxidation described in Scheme 12 in the case of using the Cu(II)/TBHP oxidation system. Under metal-free conditions the tert-butoxy radical A is probably formed via homolytic thermal decomposition of TBHP. Recently, the electrochemical generation

• were achieved using 1 equiv TBHP. This can be explained by reoxidation of Fe(II) to Fe(III) by oxygen, which is released during thermal decomposition of pyridinium nitrate presented in the system. Later, Mn-catalyzed peroxidation of alkylarenes 47 [50][62] and peroxidation of alkylarenes 49 using Ru

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• -difluoroalkenes and trifluoroalkenes in reactions with Grignard reagents [13][31]. Although, similar compounds are reported to be unstable molecules that are prone to decomposition under reaction conditions [32][33]. The goal of this work was the formation of gem-difluoro- and trifluorovinyl Michael acceptors by

Structure and thermal stability of phosphorus-iodonium ylids

• Andrew Greener,
• Stephen P. Argent,
• Coby J. Clarke and
• Miriam L. O’Duill

Beilstein J. Org. Chem. 2024, 20, 2931–2939, doi:10.3762/bjoc.20.245

• and potential decomposition pathways will enable the future design and development of new reagents. Keywords: hypervalent iodine; reagent development; structural analysis; thermal stability; thermogravimetric analysis; Introduction Hypervalent iodine(III) reagents have experienced a renaissance in

• groups or delocalisation into a π-system results in crystalline, bench-stable reagents. In the absence of stabilising factors, rapid decomposition occurs [21][22][23]. In this study, we aim to gain a fundamental understanding of the factors that stabilise phosphorus-iodonium ylids 1 (Figure 1B) [24][25

• File 1.) All compounds show a multi-step mass loss behaviour with a range of TGA decomposition onset temperatures (Tonset) between 107–137 °C, with the exception of three compounds that are stable to higher temperatures (1a: Tonset = 176 °C, ΔH = 134 J/g; 1j: 172 °C, 130 J/g; 2: 225 °C, 274 J/g; Table

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• of n-propyl mercaptane with subsequent addition of acetic anhydride, pyridine and KHF2 afforded indigo-N-rhamnoside 5c as a 2:1 mixture of α/β-anomers. The relatively low yield is a result of side reactions and decomposition, due to the rather unstable nature of the product. The reaction of 5c with

• failed under various conditions, due to decomposition by retro-aldol reaction. Interestingly, while indirubin-N-glycosides 17, thio- and selenoindirubin-N-glycosides 33 and 38 were formed as pure Z-isomers, oxoindirubin-N-glycosides 41 were formed as mixtures of E- and Z-isomers. The isolated yields of Z

•  42) [60]. Despite the absence of a lactone moiety, deprotection proved to be unsuccessful, due to decomposition. Miscelleaneous 6H-Indolo-[2,3-b]quinoxaline-N-glycosides The cyclization of isatin-N-rhamnoside β-16a with 1,2-diaminobenzene (79a) afforded 6H-indolo-[2,3-b]quinoxaline-N-glycoside β-80a

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• structural decomposition (NSD) method developed by Shelnutt and co-workers [9] and further implemented and visualized by us [8][10]. Of the four main quantifiable distortion modes, saddle-shaped porphyrins can be afforded by peri-interactions between β-substituents and the meso-substituents [3][11], or

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• . Thus, we supposed that the second visible light-mediated oxidation properly occurred generating the iminium ion which underwent decomposition. Even using 3-(N,N-dimethylamino)aniline, the corresponding spiro compound 3l was not obtained. In this case, it is assumed that the highly acidic environment of