Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• product of interest 2a. Compound 2a was identified by a combination of NMR spectroscopic methods and single-crystal X-ray structure analysis (vide infra) as the zwitterionic phospha-Michael adduct of 1 and acrylonitrile, formally stabilized by proton transfer from the phenol group to the initially formed

• ., 1997–2003) and SADABS (Version 2.10. Bruker AXS Inc.), respectively [52]. The structures were solved by direct methods and refined by full-matrix least-squares method (SHELXL97 or SHELXL19) [53]. If not noted otherwise all non-hydrogen atoms were refined with anisotropic displacement parameters. All

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• deposition onto a filter was achieved through a simple filtration protocol. We hope that the facile access and high modularity of PA-R will promote the wide-spread application of aromatic micelles, an emergent new class of soft molecular host compounds [14][15][30][31]. a) Previous methods for the water

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• common approach in academic laboratories, the ability of chemists to conduct the interpretation of experimental results becomes crucial. In addition, NMR spectroscopy is one of the methods that has been delivering digital experimental raw data for a long time. However, the way the spectra are interpreted

Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts

• Nils Clamor,
• Mattis Damrath,
• Thomas J. Kuczmera,
• Daniel Duvinage and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2

• diaryliodonium salts [29][31], as well as Pd-catalysed methods for synthesizing N-aryl carbazoles [32]. Similar procedures were published for the Cu-catalysed synthesis of aryl carbazoles from amines as well as other heterocycles such as N-acyl acridanes with nitriles using cyclic iodonium salts by Wen and Chen

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• stimulated the search for alternative catalysts and conditions for the hydration of alkynes, in order to identify safer and more sustainable methods [11][12][13]. In particular, transition-metal catalysts containing Au(I) or (III) [14][15][16][17][18][19][20][21][22][23][24], Ru(II) [25][26][27][28][29][30

• ], Pd(II) [31][32][33], Pt(II) [34][35], Fe(III) [36][37], Cu(I) [38][39][40][41], Co(III) [42][43][44], as well as other metals, have been widely studied. In addition, methods involving Brønsted acids, alone or in presence of Lewis acids as co-catalysts, have been developed [45][46][47][48][49][50][51

• identification of new catalysts as well as increasingly mild, economic and sustainable reaction conditions remain fundamental objectives for research in the field of organic chemistry. In recent years, alternative methods have been developed, including the use of different heterogeneous catalysts, to ensure

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

• Yipeng Yin,
• Reed Arneson,
• Alexander Apostle,
• Adikari M. D. N. Eriyagama,
• Komal Chillar,
• Emma Burke,
• Martina Jahfetson,
• Yinan Yuan and
• Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

• and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA 10.3762/bjoc.19.146 Abstract Long oligodeoxynucleotides (ODNs) are segments of DNAs having over one hundred nucleotides (nt). They are typically assembled using enzymatic methods such as PCR and

• ligation from shorter 20 to 60 nt ODNs produced by automated de novo chemical synthesis. While these methods have made many projects in areas such as synthetic biology and protein engineering possible, they have various drawbacks. For example, they cannot produce genes and genomes with long repeats and

• synthesized ODNs of 20–60 nt in length using PCR or ligation [8]. While these methods have made possible the emergence of research areas such as synthetic biology [9][10][11][12][13][14], they have various drawbacks [3]. (1) Owing to the short length of the starting ODNs, a large number of them are needed in

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• derived from nucleophilic carbenes. More sophisticated methods, such as the determination of the Huynh electronic parameter, should, however, be better suited to evaluate more precisely the influence of substituents on the donating ability of carbene ligands [22][76][77]. Apart from the asymmetric

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• complexity in decoding their sulfation pattern. Their charged nature necessitates the application of appropriate methods for electrostatics, ions, and solvent, particularly given their abundance in protein–GAG interfaces compared to complexes involving other classes of biomolecules. The periodicity can lead

• ligand from its bound position and allowing the ligand to approach the protein from a very distant position to the binding sites. Materials and Methods Structures and parameters Ligand preparation GAG structures used in the study consist of two parts: 1. the part from the experimental structure (heparin

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• methods. Because there are one C=C bond and one C=N bond in the molecules 3a–m, no diastereoisomers are obtained. Therefore, the 1H NMR spectra gave simple absorptions for the characteristic groups in the molecules. For further developing the scope of the [4 + 3] cycloaddition reaction, MBH esters of

• yields. The chemical structures of the spiro compounds 7a–n were established by various spectroscopy methods. In addition, the single crystal structure of compound 7a was also determined by X-ray diffraction (Figure 1). As can be seen from Figure 1, both the C–C and C–N double bonds are part of the

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• synthesize by other methods, whereas aryl halides afford dehalogenated arenes. One example also demonstrates that the approach may have utility for selectively dehalogenating compounds containing different halogens. The photoacceleration of these reactions appears to occur through photocleavage of the dimers

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

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

• antiaromatic four-membered ring. This review gives a brief overview of the methods used in the synthesis of biphenylenes and summarizes the recent studies on biphenylene-containing polycyclic conjugated compounds, elucidating their synthesis, and distinct optoelectronic properties. Keywords: acenes

• compounds [12]. Research using computational methods to investigate how benzo and benzocyclobutadiene annulations impact the ring current density of biphenylene derivatives reveals that the antiaromatic (paratropic) current density in the 4-ring structure can range widely, shifting from highly antiaromatic

• to nonaromatic limits based on the annulation modes employed [13][14]. Since Lothrop's initial successful synthesis of biphenylene in 1941 [15], numerous studies have been carried out, highlighting four prominent synthetic approaches. These methods include flash vacuum pyrolysis [16][17][18], [2 + 2

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• . It was previously shown that the PE technique gives practically the same IPPE values as they are recorded by other methods in vacuum [17]. The PE spectra as current (i) versus photon energy (hν) dependences for thin films of compounds 6–9 are built in the square root of i versus linear hν plots

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• measurement was performed at 90 K on a Bruker AXS instrument equipped with an Apex II CCD detector with Mo Kα radiation (λ = 0.71073 Å). The multi-scan method was used for absorption corrections. Structures were solved using direct methods and refined using SHELXL-2014/7 [36][37][38]. Deposition Number

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• many applications such as OLEDs, micro-LEDs, LCDs, lasers, and photodiodes by applying thin film methods and solution processes [5][6][7][8]. The performance of organic electronics is based on the active layer composition as well as the fabrication methods and processing parameters. The organic active

• pull–push fluorophore, DMB-TT-TPA (8), having TPA and DMB units as donor and acceptor units that were linked through a 4-MeOPh-substituted TT core as a π-spacer. The photophysical properties of the fluorophore were investigated by spectroscopic methods. Moreover, DMB-TT-TPA (8) was fabricated as an

• current efficiency of 10.6 cd/A, and maximum power efficiency of 6.70 lm/W. Results and Discussion Design and synthesis The OLED fluorophore, DMB-TT-TPA (8, Scheme 1), having a donor–π–acceptor (D–π–A) system, was synthesized according to our previously reported methods [20][21][22][23][36][38]. The

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• Diffraction Methods of Saint Petersburg State University Research Park for obtaining the analytical data. Funding This research was supported by the Russian Science Foundation (project grant 22-13-00005).

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• ][17][18][19][20]. Similarly, the syntheses of AmBn-type hexaphyrins, octaphyrins, or higher expanded porphyrins were handled by improved methods in recent years with the use of tripyrranes or bilanes and aldehydes [7][14][21][22][23][24][25]. In our previous studies, we used N-tosylimines throughout

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• anomericity). In this context, designing generic carbohydrate sequencing methods is both a major scientific challenge and a strategic priority [2][3]. Few years ago we proposed an original solution by bringing together the best of both sides of the analytical chemistry world: Spectroscopy and mass

• analysis, thus excluding manual interpretation. Besides, in the prospective of deploying the technology beyond the molecular spectroscopy community, it is essential to develop an automated, reliable, and robust strategy for the analysis of the spectroscopic data. Machine learning methods appear to be

• appealing candidates to address this challenge. They have been used for mass spectrometry data analysis since the 2000’s [6] and the idea of using them on vibrational spectra goes back to the early 90’s [7]. Support vector machines (SVM) and decision tree ensemble methods were benchmarked on infrared

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

• achieved, for example, by immobilizing the catalysts to a solid support [15], e.g., silica gel [16][17][18], organic polymers [19][20][21], magnetic nanoparticles [22][23], or by membrane separation, e.g., using organic solvent nanofiltration (OSN) [24][25][26], which methods can be easily implemented in

• flow systems. Accordingly, the main recycling methods rely on the immobilization of catalysts on heterogeneous supports, however, this could often lead to the deterioration of activity and/or selectivity [27]. A possible solution to avoid these drawbacks is the heterogenization of the catalyst after a

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• of methods for their synthesis is a very active area of research. Recent contributions to the synthesis of 4-quinolones made use of phosphine-mediated redox cyclization of 1-(2-nitroaryl)prop-2-ynones [39], palladium-catalyzed carbonylative cyclization of 2-bromonitrobenzenes and alkynes [40], TsCl

• ]. Despite the variety of synthetic approaches to the construction and functionalization of the 4-quinolone ring system, most of the recent studies related to microbial 2-alkyl-4-quinolones relied on variations of the age-old Conrad–Limpach and Camps methods for the construction of the heterocyclic quinolone

• core [26][36][52][53][54][55]. These methods usually give poor overall yields of the target quinolone products and require rather harsh conditions during the ring-forming step, such as prolonged heating in Ph2O (270 °C) or in dioxane/NaOH (110 °C), respectively. This, along with the importance of the C

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• novel metallaphotoredox catalysis by combining the NaI/PPh3 photoredox catalyst with a Cu(I) catalyst to accomplish diverse C–O/N cross-couplings of alkyl N-hydroxyphthalimide esters 3 with various phenols/secondary amines 30 (Scheme 13) [24]. It was anticipated the utilization of computational methods

• nature and represent some of the most prevalent frameworks in natural products, medicines, and functional materials. Despite the development of numerous synthetic methods over the past one century, chemists are still seeking more straightforward routes to access these structurally important and useful N

• academic research and industrial applications. As a result, significant efforts have been devoted to the development of various methods for the reduction of nitroarenes [39]. Recent advancements in the catalytic reduction of nitroarenes largely rely on transition-metal catalysis through direct

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• active-metal template strategies [12][13][14][15][16][17][18][19][20][21][22][23]. Other known methods are shrinking [24][25], swelling [26] or hydrogen-bond-mediated transition state stabilization [27][28][29], the latter resembling active-metal template synthesis. Regardless of the method used, the

• ) [30][31], metal-ion template (coordination bonds [22][32], ion-dipol [16], donor–acceptor (charge transfer, π–π stacking) [30][33], and oligoamide macrocycle-hydrogen acceptors (hydrogen bonding) [20][34]. In active-metal template methods (Figure 1) the metal ion acts both as template and catalyst for

• active-metal template and clipping methods to yield the target interlocked molecules via [1 + 1] or intramolecular macrocyclizations, realized through CuAAC reactions catalyzed by axle-copper(I) N-heterocyclic carbene complexes. The [2]rotaxane obtained by [1 + 1] clipping (R1) could be only observed by

Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• trifluoroacetaldehyde hydrazones. Jasiński et al. demonstrated that the CF3 group offered an appropriate electronic balance through experimental spectral analysis and computational DFT methods, and the hydrazones could be readily used to provide convenient access to azo tautomers under the acidic conditions [43]. The C

• reported practical methods, which extended the structural scope of such dipoles. This has allowed the synthesis of trifluoromethylpyrazoles by a range of regioselective [3 + 2] cycloadditions of trifluoroacetonitrile imines with electron-poor olefins [73][74][75][76] (Scheme 11b). Moreover, the

• more in-depth applications of fluoromethylated hydrazones and acylhydrazones to synthesize natural product analogues and fluorinated drugs is highly desirable. These methods should encourage the introduction of these difluoromethylated nitrogen-containing building blocks in future bioactives discovery

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• ]. Absorption correction was conducted with the multi-scan method in SADABAS software (APEX3 system) [52]. The structures were solved with directed methods in ShelxS [53] and refined with full-matrix least-square in ShelxL [53], implemented in WinGX [54] and ShelxLE [55] platforms. Non-hydrogen atoms were

• [58]. Potential electrostatic maps and electron density surfaces were calculated with DFT method from the CIF files using TONTO, also implemented in Crystal Explorer [58]. Computational methods All calculations were done with the Gaussian 16 package [59] using the B3LYP exchange and correlation

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• for the widespread adoption of Qx-based materials. To achieve this, it is important to optimize material synthesis methods, explore solution-processable routes, and develop efficient deposition techniques. These efforts will pave the way for large-scale production of electronic devices utilizing these

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• -pot, and multistep reactions in the synthesis of heterocyclic compounds. The methods have advantages of using readily available starting materials, performing streamlined reactions, producing diverse product structures, and having high pot, atom, and step economy (PASE) [79][80][81] for the diversity