Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• ; chiral halonium salt; contiguous stereocenters; halogen bonding; Mannich reaction; Introduction Halogen bonding (XB) has attracted intense research attention for its unique interaction between halogen atoms and electron-rich substituents [1]. XB has been applied to various fields of chemistry, such as

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• results in terms of yield and diastereoselectivity, when methyl or ethyl trifluoropyruvate were used as reactants. Next, we tested the influence of different substituents on the cyclohexenyl ring of the aminopyrazole 3, observing lower yields for homoallylic alcohols 5baa and 5caa in both conditions used

• the starting material 3ea, prepared from 2-indanone, the corresponding product was not observed, probably due to an increase in steric hindrance. Finally, 4-cyclohexenyl-5-aminopyrazoles bearing different substituents at the N-1 or C-3 position afforded the corresponding trifluoromethyl carbinols 5aba

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

• for material scientists [12][13][14]. One of the structural features favorable for an efficient anthracene-based blue emitter is the introduction of bulky substituents in the 9 and 10 positions, which results in a solid-state packing with limited π–π intermolecular interactions, which, in turn, tends

• to suppress undesirable fluorescence self-quenching [15]. Not only do bulky substituents disrupt intermolecular interactions of this type, they can also provide higher chemical stability and reduce or prevent the photodimerization and photo-oxidation to which all acenes are prone [13]. Furthermore

• , bulky fluorinated substituents, such as perfluoroalkyls and perfluoroaryls, have been predicted by DFT [16] and shown experimentally [17], to improve the air- and photostability of acene-containing materials, by increasing their electron affinity and/or by sterically blocking reactive sites

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• ]. Moreover, the parent diazocine is insoluble in water (precipitation in water/DMSO > 9:1). Substitution with polar substituents such as CH2NH2 provides water solubility, however, it does not restore the high Z → E conversion rates of the parent system in organic solvents, which is a disadvantage, since

• substitution. Substituents such as halogen atoms must be introduced into the N-acetyl diazocine structure during the synthesis of the building blocks. In the present work we start from mono- and dihalogenated N-acetyl diazocine 2–4 (Figure 2) and focus on the further derivatization via cross-coupling reactions

• corresponding arylated N-acetyl diazocines 7, and 9–13 in yields from 68 to 88% (Table 4). The yields increased slightly if boronic acids with electron-withdrawing groups were used. An influence of bulky substituents like carboxyl groups in ortho-position of the phenylboronic acids on the reaction was not

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

• -functionalized aldehydes with at least one stereocenter in the C3 position. The results, which are collected in Table 5, show that the kinetic resolution depends on the characteristics of the substituents. The best results were achieved for the Michael adduct 12, derived from acetylacetone, with R1 = Ph (entry

• substituents present in the starting Michael adducts. Furthermore, it has been observed that the enantioselectivity of Michael adducts decreases with time in the presence of a catalyst derived from diarylprolinol. Experimental General Information 1H NMR (400 or 500 MHz) and 13C NMR (100 MHz) spectra were

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

• optimized reaction conditions in hand, next, the substrate scope was evaluated (Scheme 2). Symmetrical biaryls with electron-deficient substituents such as Cl (4b) or CF3 (4c) afforded the respective Br(III) products 1b,c in slightly reduced yields as compared to that of 1a. Gratifyingly, electron-rich MeO

• ester moieties is critical for the synthesis of Br(III) species: the removal of one ester group (4i–k), or its replacement by NO2 (4l) or SO2t-Bu (4m) substituents in 2,2'-dibromo-1,1'-biphenyls resulted in starting material degradation with no formation of the desired product (for a complete list of

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

• atom economy, it significantly reduces the chance of migration as observed for acetyl groups. Various studies have revealed its dependence on both electron-withdrawing substituents and steric bulk on the carbonyl group [80]. It demonstrates that its migration rate is significantly increased by more

• electron-withdrawing substituents which also increase the electrophilicity of the carbonyl group. Again, more steric bulk in proximity to the carbonyl group, like in the benzoyl substituent, significantly reduces its migration property [81][82]. Hence, an increasing number of glycochemists across the world

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• is to obtain heterocyclic indole compounds conjugated with a 1,3-tropolone moiety. The variability of the products of acid-catalyzed reactions in the series of 2,3,3-trimethylindolenine with 1,2-benzoquinone derivatives depends on the nature of the substituents in the 1,2-benzoquinone. Thus, the

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• FTIR spectroscopy as well as HRMS. Table 1 shows the different substituents (R groups) for the synthesized compounds 7a–n. The 1H NMR spectra of compounds 7a–h showed one distinct singlet at 4.92 to 5.12 ppm for the two protons of one methylene group (Figure 2b’), a singlet for the NH proton in the

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

• the synthesis and characterization of over 20 new cyanins, reporting their synthetic applications and both calculated and measured their photophysical properties and redox potentials [66]. The study shows that substituents at the central position of the polymethin chain significantly affect their

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• amines with various substituents could be employed in the reaction to give the expected products. N-Methylaniline and n-butylamine were also successfully converted to the desired products 3h and 3i in 72% and 63% yields, respectively. The structures of compounds 3a–i were fully characterized by various

• substitution products 5a–n in high yields (Scheme 2). The substituents showed a marginal effect on the yields. In addition, a secondary arylamine such N-methylaniline and aliphatic amine (n-butylamine) also gave the expected products 5m and 5n in satisfactory yields. It should be pointed out that no base

Oxidation of [3]naphthylenes to cations and dications converts local paratropicity into global diatropicity

• Abel Cárdenas,
• Zexin Jin,
• Yong Ni,
• Jishan Wu,
• Yan Xia,
• Francisco Javier Ramírez and
• Juan Casado

Beilstein J. Org. Chem. 2025, 21, 277–285, doi:10.3762/bjoc.21.20

• of 1 in the neutral state and the theoretical Raman spectrum of a model molecule, m-1 (1 without the xylyl and methyl substituents, Figure S1 in Supporting Information File 1), which can be closely correlated to the spectrum of 1. In Tables S1–S6 of Supporting Information File 1, the theoretical

• spectra of neutral and oxidized species of 2 (the theoretical Raman spectrum of the model molecule m-2 (depicted in Figure S1, Supporting Information File 1), which is 2 without the xylyl and methyl substituents can be seen in Figure S3 of Supporting Information File 1). The spectrum of the neutral form

Synthesis and characterizations of highly luminescent 5-isopropoxybenzo[rst]pentaphene

• Islam S. Marae,
• Jingyun Tan,
• Rengo Yoshioka,
• Zakaria Ziadi,
• Eugene Khaskin,
• Serhii Vasylevskyi,
• Ryota Kabe,
• Xiushang Xu and
• Akimitsu Narita

Beilstein J. Org. Chem. 2025, 21, 270–276, doi:10.3762/bjoc.21.19

• also showed significant differences (Figure S5 in Supporting Information File 1), indicating an intramolecular charge-transfer character both in its ground and excited states [30][31]. DFT calculations were performed to understand the effects of the substituents on the frontier orbitals. As shown in

Synthesis of disulfides and 3-sulfenylchromones from sodium sulfinates catalyzed by TBAI

• Zhenlei Zhang,
• Ying Wang,
• Xingxing Pan,
• Manqi Zhang,
• Wei Zhao,
• Meng Li and
• Hao Zhang

Beilstein J. Org. Chem. 2025, 21, 253–261, doi:10.3762/bjoc.21.17

• , demonstrated that a wide range of disulfides were synthesized efficiently when sodium sulfinates served as substrates. The isolated yields ranged from 49% to 89% for products 2a–o. In the case of sodium arylsulfinates with various substituents on the benzene ring, we observed minimal effects on the reaction

• . For example, electron-donating groups (Me, tert-butyl, MeO, naphthyl) and electron-withdrawing groups (F, Cl, Br) attached to the benzene ring led to products 2a–i with yields ranging from 60% to 89%. Interestingly, products with strong electron-withdrawing substituents were obtained in moderate

• groups on the aryl substituents of the enaminones were tolerated and afforded the corresponding products in good to excellent yields (4a–f), with a slight decrease in the yield if 5-nitrophenyl-substituted enaminone was used as a substrate (4f). Both sodium arylsulfinates and sodium alkylsulfinates (4g–p

Effect of substitution position of aryl groups on the thermal back reactivity of aza-diarylethene photoswitches and prediction by density functional theory

• Misato Suganuma,
• Daichi Kitagawa,
• Shota Hamatani and
• Seiya Kobatake

Beilstein J. Org. Chem. 2025, 21, 242–252, doi:10.3762/bjoc.21.16

• -withdrawing substituents on the N-aryl moieties enhanced the thermal stability of the Z-isomers while maintaining the advantageous photoswitching properties upon irradiation with red light [52]. The effect of substituents on the thermal cis–trans isomerization of azobenzenes has also been widely studied, and

Visible-light-promoted radical cyclisation of unactivated alkenes in benzimidazoles: synthesis of difluoromethyl- and aryldifluoromethyl-substituted polycyclic imidazoles

• Yujun Pang,
• Jinglan Yan,
• Nawaf Al-Maharik,
• Qian Zhang,
• Zeguo Fang and
• Dong Li

Beilstein J. Org. Chem. 2025, 21, 234–241, doi:10.3762/bjoc.21.15

• good tolerance for both electron-withdrawing groups such as fluorine (–F), bromine (–Br), and chlorine (–Cl), as well as electron-donating substituents like methoxy (–OMe) and methyl (–Me), yielding the corresponding 6-membered tricyclic imidazoles in moderate to good yields (3b–h). Benzene rings

• substituted with halogen atoms (–F, –Cl, –Br) were also suitable for this transformation, efficiently giving the desired products in yields of 65–80% (3b, 3e–g), thus facilitating further functionalization possibilities. Notably, substrates with substituents at the sterically hindered 7-position of the

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• reliance on the biomimetic PS reactions, we sought to develop a de novo synthetic process that is independent of the substituents on the aromatic rings at both ends (Scheme 1c). To achieve more rapid synthesis and flexible structural diversification of the alkaloidal scaffolds, we conceived a streamlined

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

• reaction of 2 with formamide was performed within only 3 h (Scheme 3), yielding the N-substituted thienopyrimidones 5a–e in 30–99% total yield (2 steps), as well with aliphatic and (hetero)aromatic substituents. Quinoline derivatives are prevalent in nature, and many exhibit a range of biological

• of aliphatic and aromatic substituents (Scheme 4). Pyrimidines and pyrimidone-bearing indole derivatives are crucial in organic chemistry because of their extensive use as bioactive compounds with a wide array of significant biological activities (DB03074, DB03304, DB08131) [70][71][72]. In a similar

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

• enantioselectivity. Furthermore, a lactam containing a quaternary carbon center (2g) was prepared. However, a lower enantioselectivity was observed for product 2h due to the similar steric environment of the two alkyl substituents. As shown in Figure 1, a catalytic cycle was proposed for the intramolecular C–H

• afforded the product 10g in good yield. Acetylenes containing tolyl and trifluorophenyl substituents also exhibited improved reactivity (10h and 10i). Heteroaromatic acetylenes were effective in this transformation, forming N-acyl amidines 10j and 10k, respectively. On the other hand, the use of linear

• leads to the formation of the N-acyl amidine product 10. 1.4 N-Arylation of dioxazolones Amides bearing N-substituents are key structural motifs in a wide range of polymers [82], natural products [83], and pharmaceuticals [84][85]. Conventional synthetic routes for N-arylamides typically involve the

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

• toxic chemical oxidants and releasing hydrogen gas as the sole byproduct. Various benzamides 1 and terminal arylalkynes 2 bearing electron-rich or electron-withdrawing groups provided the desired products 3 with high chemoselectivities. However, terminal alkynes with alkyl substituents did not yield the

• of substrates, including arylacetylenes with electron-donating and electron-withdrawing groups, and ferrocenyl amides with alkyl and acyl substituents on the other Cp ring. Additionally, the reaction showed similar reactivity and enantioselectivity on a 1 mmol scale. In 2020, Mei et al. reported the

• sterically hindered hydroquinone promotes 1,4-addition, resulting in the formation of an α-arylated intermediate 40, and different products are generated depending on the substituents on the Schiff base. For example, a methyl-substituted Schiff base provided a chiral quinone 35 after 1,4-addition and

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

• successfully synthesize a range of 2-arylbenzofurans with various substituents. The reaction, which proceeded under mild conditions, involved β-fluorine elimination from nickelacyclopropanes formed by the interaction of 2-fluorobenzofurans with zero-valent nickel species. This protocol facilitates orthogonal

• simultaneously between E and the arylboronic acids 2, leading to the formation of G (Scheme 5, path c). The intermediates G then undergo reductive elimination to yield 3. To assess the impact of halogen substituents, we also examined reactions of 2-halogenated benzofurans 1a-X (1a-Cl: X = Cl; 1a-Br: X = Br; 1a-I

• nickelacyclopropane Eb in a stoichiometric reaction. Screening of conditions for coupling of 1b with 2b. Effect of halogen substituents. Supporting Information Supporting Information File 82: Detailed experimental procedures and spectral data. Acknowledgements This work was partially performed using facilities of

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

• heteroannulation [50]. The SPINOL-derived chiral phosphoric acid C26 catalyzed the formation of axially chiral products 81 from diarylketones 79a–f and ketoesters 80a–c (Scheme 26). The substrate scope contained a broad range of substituents, including electron-donor groups and whole benzene rings. The authors

• -naphthols, new atroposelective reactions of quinones and iminoquinones were developed [63]. The reaction of quinones with an ester group 109 and indoles with alkyl substituents 110 catalyzed by CPA C29 provided products 112 with regioselectivity on the pyrrole ring of indole (Scheme 35). On the contrary

• in the regioselectivity change. Song et al. broadened the scope of usable substrates for the asymmetric arylation of naphthoquinones 115 with indolizines 114 catalyzed by CPA (R)-C23 forming atropoisomers 116 (Scheme 36) [64]. A broad range of indolizine substrates was tested with substituents in

Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• -nitrostyrene (4a), precursor of most of the hallucinogenic 2C-X family (Table 1). This method was also tested on other types of scaffolds to investigate its potential general applications and effects on other substituents. As sodium borohydride per se does not reduce ester nor nitro functionalities [15][16][17

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

• studies, revealing that their photophysical behavior can be affected by the different substituents in the donor carbazole group. Keywords: carbazole; D−A−D type; noble-metal-free system; 9‑phenyl-9-phosphafluorene oxide; photophysical properties; Introduction π-Conjugated molecular materials containing

• hand, we turned our attention to the synthesis of PhFlOP-based compounds through a Cs2CO3-facilitated nucleophilic substitution with substituted carbazoles as the nucleophiles (Scheme 2). For example, tert-butyl, bromo, carbazolyl, or phenyl substituents were introduced into the carbazoles. To our

• has insignificant effect on the molecular ground state of 7-H. The PL spectra of the PhFlOP-based compounds 7 in toluene at room temperature are shown in Figure 3, and the λem values are included in Table 2. Different emission wavelengths are observed due to the various substituents present in the

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

• acid as additive and a mixture of toluene and water provided the best results in terms of yield and enantioselectivity. A wide scope was explored, including electron-donating substituents and electron-withdrawing groups, as well as heterocycles, giving densely functionalized chiral azaspirocyclic

• moiety in up to 99% yields, up to 93% ee and >20:1 dr (Scheme 5) to be obtained. In general, the steric and electronic properties of the conjugated imines had a slight effect on the enantioselectivities of the reactions. However, the authors pointed out that the azlactones with different substituents at

• -azadienes bearing substituents at the ortho-position were tested, the enantioselectivities decreased, probably due to higher steric hindrance. The mechanism of the reaction is depicted in Scheme 7; firstly, the dual activation of the azadiene and the enol form of the azlactone through hydrogen bonding with