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

• , reacts with an enol species activated by the copper catalyst, affording the final product. The same research group reported an extension of this study by starting from arylacetylenes instead of arylketones [42]. Imidazo[1,2-a]pyridine derivatives 33 can be achieved by Cu(OTf)2-catalyzed multicomponent

Intramolecular C–H arylation of pyridine derivatives with a palladium catalyst for the synthesis of multiply fused heteroaromatic compounds

• Yuki Nakanishi,
• Shoichi Sugita,
• Kentaro Okano and
• Atsunori Mori

Beilstein J. Org. Chem. 2024, 20, 3256–3262, doi:10.3762/bjoc.20.269

• % yield, respectively. The related reaction is also carried out with amides of non-pyridine derivatives terephthal- and benzamides to afford multiply fused heterocyclic compounds in 81% and 89% yields, respectively. Keywords: intramolecular C–H arylation; multiply fused heterocycles; palladium acetate

• ][7] are found in a variety of advanced materials [8][9] and biologically important molecules [10][11][12]. A wide range of pyridine derivatives have been employed as extractants of metal ions through chelation [13]. Phenanthrolines, a class of pyridine derivatives, have attracted attention for the

• effective to afford 2a in 94% yield. The reaction was then carried out with several pyridine derivatives including amide derivatives composed of 6-methylpicoline (1b) and unsubstituted picoline (1c) as summarized in Table 2. When the reaction was examined in the absence of a phosphine ligand, the yields of

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

• Anthony J. Burke and
• Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

• -dihydro[1,3]thiazolo[4,5-b]pyridine derivatives that exhibited strong herbicidal activity against commercially significant grass weeds in preemergence greenhouse tests. The synthetic route for this new family of compounds was developed and optimized, involving several reaction steps, included Pd-catalyzed

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• ) > PcMn > PcNi > PcZn. In previous studies, various pyridine derivatives such as 2-pyridone, its derivatives, and 4-pyridone [23][24][25][26][27][28], were subjected to the Elbs peroxydisulfate oxidation, resulting in yields of up to 38% for the corresponding 5-hydroxy derivatives (2,5-dihydroxy

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• with heterocyclic thiols leads to the formation of S-functionalized catechols. In the case of the acid-catalyzed reaction between 3,5-di-tert-butyl-6-methoxymethylcatechol and mercapto-substituted thiazole or pyridine derivatives, catechol−thioethers are formed with an additional methylene bridge

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

• synthesize tricyclic pyridine derivatives in a single step (Scheme 22) [75]. Zhang and Yu et al. also developed a cyclization of 2-isocyanobiaryls using a photoredox system [76][77][78][79][80] in which carbon radicals were generated by a photoredox reaction of α-bromopropanoates under visible light

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• } and 1{8}) or showed low conversion (halogenated derivatives 1{9–11}); 4-aminopyrimidines 1{12–16} also demonstrated low conversion; pyridine derivatives with electron-withdrawing substituents (such as NO2 at C-3 or C-5 positions, as well as CN, SO2NH2, or C(O)NH2 at the C-3 atom) did not work

• (compounds 1{17–21}); for pyridazine or pyrazine derivatives, even the presence of halogen atoms was sufficient to deactivate the substrate (e.g., compounds 1{22–24}); a dialkylamino or alkoxy group at the C-6 position of pyridine derivatives also hampered the substrate’s reactivity (e.g., compounds 1{25–27

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

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

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

• a [4 + 2] cycloaddition process [45]. Very recently, we also found that base-promoted [4 + 2] cycloaddition of salicyl N-tosylimines and 5,6-unsubstituted 1,4-dihydropyridines resulted in novel tetrahydrochromeno[3,2-b]pyridine derivatives in satisfactory yields [46]. Inspired by these efficient

Mild and efficient synthesis and base-promoted rearrangement of novel isoxazolo[4,5-b]pyridines

• Vladislav V. Nikol’skiy,
• Mikhail E. Minyaev,
• Maxim A. Bastrakov and
• Alexey M. Starosotnikov

Beilstein J. Org. Chem. 2024, 20, 1069–1075, doi:10.3762/bjoc.20.94

• method, however, the cyclization occurred under drastic conditions (NaH, DMF, 130 °C) as it was reported in patent literature [23]. We assumed that a similar synthetic route (nitrosation/SNAr) would be applicable for the synthesis of isoxazolo[4,5-b]pyridine derivatives bearing other EWG in position 3

• mixture was treated with K2CO3 in DMF at 60 °C, compound 13a was isolated in 92% yield (from 7a) (Table 1, entry 1). Such rearrangement has been reported previously for the benzo[d]isoxazole series [30], however, it has not been observed for isoxazolo[4,5-b]pyridine derivatives. It was found that the

HPW-Catalyzed environmentally benign approach to imidazo[1,2-a]pyridines

• Luan A. Martinho and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2024, 20, 628–637, doi:10.3762/bjoc.20.55

• 1, aromatic/heteroaromatic aldehydes 2, and isocyanides 3 to obtain the imidazo[1,2-a]pyridine derivatives 4 (Scheme 2). In general, the efficiency of the HPW-catalyzed GBB reaction is very dependent upon the type of 2-aminopyridine or isocyanide compound used, and not influenced by different

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• chemoselective and regioselective CDC between pyridines and ethers, which used Sc(OTf)3 as the catalyst and DTBP as the oxidant (Scheme 36) [101]. This strategy allowed the synthesis of a series of α-substituted pyridine derivatives. The control experiments showed that the mechanism may proceed via a radical

• . With the development of the CDC reaction, the catalytic effect of rare earth metals on CDC has also been explored. Xing et al. developed an Y(OTf)3-catalyzed CDC reaction of ethers, especially open chain ethers with pyridine derivatives (Scheme 40) [108]. The method has the advantages of simple

New one-pot synthesis of 4-arylpyrazolo[3,4-b]pyridin-6-ones based on 5-aminopyrazoles and azlactones

• Vladislav Yu. Shuvalov,
• Ekaterina Yu. Vlasova,
• Tatyana Yu. Zheleznova and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2023, 19, 1155–1160, doi:10.3762/bjoc.19.83

• formation of the target products with low yields [21]. Therefore, the development of a new effective method for the preparation of 4-arylpyrazolo[3,4-b]pyridin-6-ones is an urgent task. Results and Discussion One of the rational approaches to the synthesis of fused pyridine derivatives is based on the

Pyridine C(sp²)–H bond functionalization under transition-metal and rare earth metal catalysis

• Haritha Sindhe,
• Malladi Mounika Reddy,
• Karthikeyan Rajkumar,
• Akshay Kamble,
• Amardeep Singh,
• Anand Kumar and
• Satyasheel Sharma

Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62

• . In the same year, Tsurugi and Mashima reported the use of rare earth metal complexes for the insertion of nonpolar unsaturated substrates (C=N) into the ortho-C–H bond of pyridine derivatives [54]. They carried out the C–H aminoalkylation of pyridines 1 using yttrium complex 26 with nonactivated

• providing various ortho-aminoalkylated products 36 whereas ortho-alkylated pyridine derivatives 38 were obtained when using NP1-Sc as the catalyst (Scheme 8). Attributing to the strong coordination of unsubstituted pyridine with Rh(I) catalysts, C–H alkylations of pyridine lacking ortho-blocking groups is a

Transition-metal-catalyzed C–H bond activation as a sustainable strategy for the synthesis of fluorinated molecules: an overview

• Louis Monsigny,
• Floriane Doche and
• Tatiana Besset

Beilstein J. Org. Chem. 2023, 19, 448–473, doi:10.3762/bjoc.19.35

• catalysis reported by He and Pan [137]. Palladium-catalyzed (ethoxycarbonyl)difluoromethylthiolation reaction of 2-(hetero)aryl and 2-(α-aryl-vinyl)pyridine derivatives reported by Besset [138]. Pd(II)-catalyzed trifluoromethylselenolation of benzamides derived from 5-methoxy-8-aminoquinoline reported by

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• [74][76][80][86][87][88]. To facilitate the anodic oxidation of N-hydroxyphthalimide, basic pyridine derivatives are used as the N-hydroxyphthalimide proton acceptors [87]. In many cases electrolysis can be performed in the galvanostatic mode in a simple undivided cell, which is convenient for

An isoxazole strategy for the synthesis of 4-oxo-1,4-dihydropyridine-3-carboxylates

• Timur O. Zanakhov,
• Ekaterina E. Galenko,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2022, 18, 738–745, doi:10.3762/bjoc.18.74

• , Supporting Information File 1). Compounds 2 have several reactive centers that make them attractive starting materials for the synthesis of new libraries of 4-pyridone and pyridine derivatives (Scheme 6). The methoxycarbonyl group of compound 2c was selectively reduced to give 3-(hydroxymethyl)pyridin-4(1H

Syntheses of novel pyridine-based low-molecular-weight luminogens possessing aggregation-induced emission enhancement (AIEE) properties

• Masayori Hagimori,
• Tatsusada Yoshida,
• Yasuhisa Nishimura,
• Yukiko Ogawa and
• Keitaro Tanaka

Beilstein J. Org. Chem. 2022, 18, 580–587, doi:10.3762/bjoc.18.60

• electron-withdrawing groups [13][14][15]. Previously, we have reported various pyridine derivatives, including polysubstituted pyridines and fused pyridines, which exhibited strong fluorescence in organic solvents (ethanol and dichloromethane) [16][17][18][19], while their fluorescence in aqueous media was

• heterocyclic compounds, such as ring-fused pyridines (pyrido[1,2-a]pyrrolo[3,4-d]pyrimidines) and secondary aminopyridines (N-methyl-4-((pyridin-2-yl)amino)-substituted maleimides), by changing the substituents at position 5 of the 2-aminopyridine. Interestingly, among these pyridine derivatives, secondary

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• interesting results [137]. The authors observed that the desired product 95 was obtained with very low yield, due to the competition between the Kochi–Anderson [76] reaction and the Minisc reaction (Scheme 31) generating a mixture of polymeric pyridine derivatives [142]. The Minisci reaction [142] is a

Multi-faceted reactivity of N-fluorobenzenesulfonimide (NFSI) under mechanochemical conditions: fluorination, fluorodemethylation, sulfonylation, and amidation reactions

• José G. Hernández,
• Karen J. Ardila-Fierro,
• Dajana Barišić and
• Hervé Geneste

Beilstein J. Org. Chem. 2022, 18, 182–189, doi:10.3762/bjoc.18.20

• reactivity of pyridine derivatives with NFSI, which are known to generate phenylsulfonyl fluoride via a transient generation of N-sulfonylpyridinium salts [37]. Analysis by 19F NMR spectroscopy of the crude reaction mixture of 3b and NFSI revealed the presence of PhSO2F (Scheme 3d), thus confirming the

Direct C(sp³)–H allylation of 2-alkylpyridines with Morita–Baylis–Hillman carbonates via a tandem nucleophilic substitution/aza-Cope rearrangement

• Siyu Wang,
• Lianyou Zheng,
• Shutao Wang,
• Shulin Ning,
• Zhuoqi Zhang and
• Jinbao Xiang

Beilstein J. Org. Chem. 2021, 17, 2505–2510, doi:10.3762/bjoc.17.167

• ; Morita–Baylis–Hillman carbonates; Introduction Pyridines are among the most important heterocyclic structural moieties in many biologically active natural products, pharmaceuticals, and agrochemicals [1][2][3]. Therefore, the development of efficient strategies for functionalized pyridine derivatives

• synergistic catalyzed allylic alkylation between electron-deficient 2-ethyl benzoxazoles and MBH carbonates by the combination of a Lewis base and a metal salt [24]. In their studies, although pyridine derivatives were also applicable in the reaction, the presence of a strong electron-withdrawing NO2 group

Recent advances in the tandem annulation of 1,3-enynes to functionalized pyridine and pyrrole derivatives

• Yi Liu,
• Puying Luo,
• Yang Fu,
• Tianxin Hao,
• Xuan Liu,
• Qiuping Ding and
• Yiyuan Peng

Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163

• in many natural products, pharmaceuticals, and bioactive molecules. For instance, some pyridine derivatives have been used for therapy of HIV, cancer, inflammation, microbial infection and so on [1][2][3][4][5]. In addition, it is also an important synthetic unit, which is frequently used as catalyst

• or ligand in organic chemistry [6][7][8][9][10]. Therefore, the development of efficient methods for the synthesis of pyridine derivatives has attracted considerable attention [11][12][13][14]. The industrial synthetic methods of pyridines mainly involve: i) extraction from coal tar; ii) condensation

• pyridine derivatives have been developed through the intramolecular or intermolecular tandem addition annulation/functionalization of alkynes with some N-containing compounds, such as nitriles, oximes, and imines [15][16][17][18][19]. The pyrrole structural motif is also an invaluable five-membered N

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

• by direct fluorination (10% F2/N2) of the pyridine in acetonitrile and in the presence of a suitable salt at low temperature (method B in Scheme 10). This one-step process was successfully applied to many other pyridine derivatives (method B in Figure 2). It was finally shown that the stable N

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90