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

• -like properties, this protection group contributed towards the formation of 1,2-trans glycosides when installed in the C-2 position. Similarly, the (2-nitrophenyl)acetyl (NPAc, 44) group has also been used for obtaining 1,2-trans glycosides [126]. C-2 NPAc-protected thioethyl donor 47 underwent

• -nitrophenyl)propyloxycarbonyl (NPPOC, 46) group as the 1,2-trans stereodirecting group and its use in iterative oligosaccharide synthesis [128]. Other ester-type neighbouring group participation in glycosylation reactions: Sato et al. worked on the development of new types of ester-protecting groups for the C

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

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

• 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

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

• axis (Scheme 12). Wei, Du, and co-workers developed an atroposelective formal (3 + 3) annulation of 4-nitrophenyl 3-arylpropiolates 39 with 2-sulfonamidoindolines 40 [32]. The NHC catalyst derived from triazolium salt C14 afforded the best results in terms of chemical yields as well as

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

• Shin-ichiro Kurimoto,
• Kouta Inoue,
• Taito Ohno and
• Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

• . Cells were seeded at a density 2 × 103 cells/well (198 μL/well) in 96-well plates, and test samples dissolved in DMSO (2 μL) were added to each well. The cells were then incubated for 72 hours. Cell viability was assessed using a WST-8 [2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• orientation of p-nitrophenyl units, due to the shielding of the bound aldehyde substrate from the incoming diene. The catalytic inactivity of 5 demonstrated the requirement of macrocyclic character for the potential catalysts. Later in 2009, the same group reported an organocatalyzed diastereoselective aldol

Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• yields of the products 3g and 3h. The more electron-withdrawing m-fluorophenyl (2i), o-chlorophenyl (2j), o-bromophenyl (2k), o-trifluoromethylphenyl (2l), and o-nitrophenyl (2m) groups also resulted in comparable yields of 3g–m, respectively, indicating no significant effect of substitutents on the aryl

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• diselenide, the addition of PhSe• to alkenes proceeds 10 to 50 times slower than PhS• [29]. For this reason, the addition of (PhSe)2 to isocyanides, whether aliphatic or aromatic, rarely proceeds. The exception is the addition to p-nitrophenyl isocyanides, which does proceed, but this is because the electron

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• substrate (1-(diphenylmethylene)-2-(4-nitrophenyl)hydrazine), which displayed three oxidation peaks (0.9, 1.7 and 2.2 V vs Ag+/Ag in HFIP ). The authors assumed that the two first peaks would correspond to the oxidation of 8 to 10 and 11 to 12 and that the oxidation of 10 would be responsible for the final

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• ) bromide, it afforded compound 2 with a very low yield (2%). When the phosphonation was performed with diethyl phosphonate in the presence of Pd(PPh3)4 as catalyst and trimethylamine, compound 2 was formed with a good yield (72%) (Scheme 1). The corresponding (4-nitrophenyl)phosphonate derivative 6 [51

• ). Compound 15 reacted with diethyl phosphonate in the presence of a strong base (sodium methoxide) to afford diethyl [hydroxy(4-nitrophenyl)methyl]phosphonate (16) in 81% yield (Scheme 4). The hydrogenolysis of this compound under H2 on Pd/C afforded quantitatively diethyl [hydroxy(4-aminophenyl)methyl

Domino reactions of chromones with activated carbonyl compounds

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1256–1269, doi:10.3762/bjoc.20.108

• groups were tolerated, including 3- and 4-nitrophenyl and 3,5-dinitrophenyl. The formation of the product proceeds analogously to the reaction leading to benzophenones 19 and 21. The yields were in most cases moderate to good. A poor yield (7%) was obtained from the chromone substituted by a 2-thienyl

• adjacent to the phenol moiety resulted in formation of intermediate L and lactonization gave the final products. The regioselectivity of the cyclization can be explained by steric hindrance of the carbonyl group adjacent to the 2-nitrophenyl moiety containing an ortho-substituent. Interestingly, in case of

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

• compounds was obtained in one step [33]. Clawson et al. showed that it was possible to achieve the synthesis of substituted 3-alkoxyindoles via the palladium-catalyzed reductive N-heteroannulation of 1-(2-nitrophenyl)-1-alkoxyalkenes. Only in one case 2-(1-ethoxyvinyl)-3-nitropyridine was used [34]. The

• indolo[1,2-c]quinazolin-6(5H)-one derivatives. Finally, starting from 1,2-bis(2-nitrophenyl)ethene and 1-methoxy-2-nitro-3-(2-nitrostyryl)benzene the related indolo[3,2-b]indoles were not observed (Scheme 17). One year later, by using continuous flow technology, Gutmann, Kappe and colleagues developed a

• -catalyzed reductive cyclization of 1,2-bis(2-nitrophenyl)ethene and 1,1-bis(2-nitrophenyl)ethene derivatives. Flow synthesis of 2-substituted indoles by reductive carbonylation. Pd-catalyzed synthesis of variously substituted 3H-indoles from nitrostyrenes by using Mo(CO)6 as CO source. Synthesis of indoles

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• were then submitted to deprotection protocols as described in the literature [20][21]. However, the removal of the tosyl group of pyrroline 1b proved to be a challenging task. After several unsuccessful attempts to remove the tosyl group, we decided to evaluate the (p-nitrophenyl)sulfonyl (Ns) and (o

• -nitrophenyl)sulfonyl (2-Ns) as alternative protecting groups of 2,5-dihydro-1H-pyrrole (Scheme 5). Although the results with the 2-Ns protecting group were somewhat disappointing, the results with 4-Ns group were more promising, even with a welcome increase in the enantiomeric ratio in some cases (4dd and 4de

The unique reactivity of 5,6-unsubstituted 1,4-dihydropyridine in the Huisgen 1,4-diploar cycloaddition and formal [2 + 2] cycloaddition

• Xiu-Yu Chen,
• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 982–990, doi:10.3762/bjoc.19.73

• ) as eluent to give the pure product for analysis. 7,8-Diethyl 4-methyl 2-benzyl-3-methyl-5-(4-nitrophenyl)-2-azabicyclo[4.2.0]octa-3,7-diene-4,7,8-tricarboxylate (5e): yellow solid, 36%; mp 161–163 °C; 1H NMR (400 MHz, CDCl3) δ 8.07–8.05 (m, 2H, ArH), 7.37–7.34 (m, 2H, ArH), 7.33–7.29 (m, 3H, ArH

• ): [M + H]+) calcd for C29H31N2O8, 535.2075; found, 535.2076. 4,5-Diethyl 3-methyl 1-benzyl-2-methyl-3a-(4-nitrophenyl)-1,3a,4,6a-tetrahydrocyclopenta[b]pyrrole-3,4,5-tricarboxylate (6e): yellow solid, 35%; mp 153–155 °C; 1H NMR (400 MHz, CDCl3) δ 7.98 (d, J = 8.8 Hz, ArH), 7.45–7.37 (m, 5H, ArH), 7.30

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• [25] that ethyl 2-bromo-2'-nitrobenzoylacetate reacts with thiobenzamide to give not only the expected 4-(2-nitrophenyl)-2-phenylthiazole-5-carboxylate, but also the dimerization product of thiobenzamide – i.e., 3,5-diphenyl-1,2,4-thiadiazole (XV). Similar observations have been made with other

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• molecule 5b. In the crystal packing (Figure S66 in Supporting Information File 1), molecules 5e tend to approach π-donor DMAN and π-acceptor p-nitrophenyl fragments, and the shortest distance between the two molecules is 2.810 Å (Figure S67 in Supporting Information File 1). The alternation of the C–C bond

• lengths in the aryl rings of molecules 5d and 5e may indirectly indicate the conjugation of the π-donor fragment with the π-acceptor p-nitrophenyl or p-cyanophenyl fragments. The qr parameter, calculated according to equation [32] (Figure 6) and characterizing the quinoid character of the aryl ring, was

• )benzonitrile and N,N-dimethyl-4-((4-nitrophenyl)ethynyl)aniline in chloroform solution are 373 and 416 nm, respectively [35]. In the same time, λmax for 2-((4-nitrophenyl)ethynyl)-1,8-bis(dimethylamino)naphthalene is 474 nm [36]. The red shift observed in the spectrum of this compound as well as in the spectra

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• according to experimental literature with slight modification [20]. α-Glucosidase (0.05 U/mL) and substrate, p-nitrophenyl-α-ᴅ-glucopyronoside (p-NPG) (1 mM) were dissolved in 0.1 M sodium phosphate buffer (pH 6.9). Fifty μL of sample (1 mg/mL in 10% DMSO) and 50 μL of α-glucosidase were preincubated at 37

New triazole-substituted triterpene derivatives exhibiting anti-RSV activity: synthesis, biological evaluation, and molecular modeling

• Elenilson F. da Silva,
• Krist Helen Antunes Fernandes,
• Denise Diedrich,
• Jessica Gotardi,
• Marcia Silvana Freire Franco,
• Carlos Henrique Tomich de Paula da Silva,
• Ana Paula Duarte de Souza and
• Simone Cristina Baggio Gnoatto

Beilstein J. Org. Chem. 2022, 18, 1524–1531, doi:10.3762/bjoc.18.161

• of a 1-(3-nitrophenyl)-1,2,3-triazol-4-yl substituent in the C-28 position of both compounds 7 and 8 (EC50 = 0.314 and 0.053 µM, respectively) increased their antiviral activity, compared to that of the scaffolds 1 and 2 (EC50 = 5.3 and 17.3 µM, respectively) and acetylated compounds 3 and 4 (EC50

• -triazole pharmacophore via click chemistry reaction catalyzed by copper. The introduction of a proper 1-(3-nitrophenyl)-1H-1,2,3-triazole substituent into triterpenes resulted in promising anti-RSV activity, compared to that of RBV, one of the few drugs available for treating RSV infections. Compound 8 was

Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• catalyze the reaction (Table 1, entries 19–22). With the best conditions in our hands (Table 1, entry 11), different diformylated dipyrromethanes were subjected to condensation reactions. Electron-withdrawing 4-chlorophenyl, pentafluorophenyl, and 4-nitrophenyl-substituted corrole compounds were isolated

Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold

• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109

• were generally good to excellent throughout. The notable exception is the evident drop in the isolated yield in the case of substrates bearing a nitrophenyl group at position 1 (cf. compounds 10j and 10n). This lowering of the yield, however, likely has to do with the combination of the nitrophenyl

• substituent and an N-alkyl group (considering that N-aryl nitrophenyl-substituted compound 10o was obtained in a respectable 91% yield). The structures of compounds 10a–s were unequivocally confirmed by 1H and 13C NMR spectroscopy (paying a particular attention to the appearance of the C=N2 signal in the

Synthesis of 5-unsubstituted dihydropyrimidinone-4-carboxylates from deep eutectic mixtures

• Sangram Gore,
• Sundarababu Baskaran and
• Burkhard König

Beilstein J. Org. Chem. 2022, 18, 331–336, doi:10.3762/bjoc.18.37

• -unsaturated ketoesters, such as (E)-ethyl 4-(4-nitrophenyl)-2-oxobut-3-enoate (17), afforded the corresponding 5-unsubstituted DHPM derivative 18 in good yield (entry 6, Table 1). Similarly, heteroaromatic aldehyde derived ketoester 21, also underwent the tandem reaction to give the corresponding 5

Ready access to 7,8-dihydroindolo[2,3-d][1]benzazepine-6(5H)-one scaffold and analogues via early-stage Fischer ring-closure reaction

• Irina Kuznetcova,
• Felix Bacher,
• Daniel Vegh,
• Hsiang-Yu Chuang and
• Vladimir B. Arion

Beilstein J. Org. Chem. 2022, 18, 143–151, doi:10.3762/bjoc.18.15

• -phenylhydrazine in acetic acid that delivers methyl 2-(1-benzyl-3-(2-nitrophenyl)-1H-indol-2-yl)acetate in 55% yield. Keywords: anticancer; Fischer indole synthesis; Heck reaction; heterocyclic compounds; indolobenzazepines; latonduines; paullones; Introduction Indolobenzazepines are fused heterocyclic

• ]. The N-protected 3-(2-nitrophenyl)indole was considered an important intermediate in this synthetic route (Scheme 1). The second retrosynthetic pathway (b) involved cyclization at position 3 of the indole ring, with a halo-aryl precursor [24]. In this case N-protected indole-2-acetic acid was regarded

• as the key intermediate. The third pathway (c) was centered around a ring-closure reaction via lactam-bond formation from a precursor that contains a carboxylic ester in position 2 and an o-aniline moiety in position 3 of the indole ring by Fischer indole synthesis from methyl 4-(2-nitrophenyl)-3

A photochemical C=C cleavage process: toward access to backbone N-formyl peptides

• Haopei Wang and
• Zachary T. Ball

Beilstein J. Org. Chem. 2021, 17, 2932–2938, doi:10.3762/bjoc.17.202

• then account for the isolation of the acetylated analogue 9. The photochemical pathway described here represents a formal oxidative olefin cleavage of vinylogous nitroaryl-modified amides and ethers. The pathway adds to the diversity of photochemical pathways known for 2-nitrophenyl systems, and the

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• , 67.32; H, 3.44; N, 6.83; found: C, 67.18; H, 3.06; N, 6.97. (E)-2-(((2-(4-Nitrophenyl)-4-(trifluoromethyl)quinolin-6-yl)imino)methyl)phenol (3ea): Orange solid, yield 65%; mp 223–226 °C; 1H NMR (600 MHz, CDCl3) δ 12.85 (s, 1H, OH), 8.77 (s, 1H, CH=N), 8.41 (s, 4H, 4-NO2C6H4), 8.34 (d, J = 8.7 Hz, 1H, H

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• in a satisfactory yield. Thus, a series of these catalysts was screened. The best results in term of the yield (83%) and ee (90%) were obtained while using the catalyst having a p-nitrophenyl group on the other side of thiourea moiety in CCl4 in the presence of 4 Å molecular sieves (Table 16). The