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

• toluenesulfinate moiety, producing the 2-aminooxazoline derivative 44 as the main product. In this report, it was stated that this result can be avoided by replacing formaldehyde with glyoxylic acid (Scheme 40). Using similar reaction conditions, the authors obtained the desired 1,4-disubstituted imidazole

• derivatives 43 with very good yields and for a wide range of amines and tosyl methyl isocyanides, after a decarboxylation/elimination sequence of the putative intermediate 45. This procedure was the basis for the work by Dow et al. on the synthesis of a new series of CB1 receptor antagonists (cannabinoid-1

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

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

• Olfa Mhasni,
• Jalloul Bouajila and
• Farhat Rezgui

Beilstein J. Org. Chem. 2023, 19, 1251–1258, doi:10.3762/bjoc.19.93

• reflux with an azeotropic distillation, was successfully carried out with no catalysts or additives, affording the corresponding N-substituted imidazole derivatives in good yields. On the other hand, in refluxing toluene or methanol, the aza-Michael addition of imidazole onto acyclic MBH alcohols was

• biological activities [1][2][3][4][5][6][7]. In this context, the imidazole moiety is widely known as one of the most important groups which plays efficient roles in bioactive compounds [8]. For instance, a number of N-substituted imidazole derivatives, such as miconazole, ketoconazole, genaconazole, and

• in the presence of imidazole (2a), as a powerful nucleophilic additive, affording, via competitive allylic nucleophilic substitution in toluene at reflux, a mixture of the corresponding N-substituted morpholine and N-substituted imidazole derivatives 6 [23]. In addition, a literature survey showed

Functionalization of imidazole N-oxide: a recent discovery in organic transformations

• Koustav Singha,
• Imran Habib and
• Mossaraf Hossain

Beilstein J. Org. Chem. 2022, 18, 1575–1588, doi:10.3762/bjoc.18.168

• -saving drugs and medicines. Imidazole is one of the pharmacologically important heterocyclic motifs found in widely used and well-known medicines and bioactive molecules. The applications of imidazole derivatives displaying various biological activities, motivated researchers for the development of more

• potent and significant drugs containing imidazole moieties. The formation of imidazole derivatives can be achieved using imidazole N-oxide as starting material. In this review, the scope of substrates and reaction mechanisms of various synthetic approaches using imidazole N-oxides as substrates are

• compounds exhibit various bioactivities, such as antimicrobial [4], antidiabetic [5], antiviral [6], antihypertensive, anticancer [7], anti-inflammatory [8], analgesic [9], antimicrobial and so on (Figure 1). For the synthesis of imidazole derivatives, there are several interesting methodologies available

Scope of tetrazolo[1,5-a]quinoxalines in CuAAC reactions for the synthesis of triazoloquinoxalines, imidazoloquinoxalines, and rhenium complexes thereof

• Laura Holzhauer,
• Chloé Liagre,
• Olaf Fuhr,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2022, 18, 1088–1099, doi:10.3762/bjoc.18.111

• investigation of the formation of 1,2,3-triazoloquinoxalines, denitrogenative annulation towards imidazole derivatives could be identified as a competing reaction for some substituted quinoxalines. Following the proposed mechanism, a dependency of obtained product ratio on the alkyne concentration was observed

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

• capacity of the nitrogen with the lone electron pair in 3b, and probably in 3a, to react with NFSI at the sulfonyl group to facilitate the formation of phenylsulfonyl fluoride (Scheme 3c). Other imidazole derivatives such as 2-methylimidazole (3c) and benzimidazole (3d) also underwent sulfonylation

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

Photochromic diarylethene ligands featuring 2-(imidazol-2-yl)pyridine coordination site and their iron(II) complexes

• Andrey G. Lvov,
• Max Mörtel,
• Anton V. Yadykov,
• Frank W. Heinemann,
• Valerii Z. Shirinian and
• Marat M. Khusniyarov

Beilstein J. Org. Chem. 2019, 15, 2428–2437, doi:10.3762/bjoc.15.235

• yield is lower [40]. The quantum yields for cyclohexenone derivatives 6 and 7 are in the 0.22–0.27 range. Similar to some other cyclopentene derivatives [41], diarylethene 4 possesses low cycloreversion quantum yields at 4–6%. However, in accordance with previous results on imidazole derivatives [42], 3

Synthesis and selected transformations of 2-unsubstituted 1-(adamantyloxy)imidazole 3-oxides: straightforward access to non-symmetric 1,3-dialkoxyimidazolium salts

• Grzegorz Mlostoń,
• Małgorzata Celeda,
• Katarzyna Urbaniak,
• Marcin Jasiński,
• Vladyslav Bakhonsky,
• Peter R. Schreiner and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2019, 15, 497–505, doi:10.3762/bjoc.15.43

• analogously to those of 1-alkylimidazole 3-oxides to give imidazol-2-thiones and imidazol-2-ones, respectively. Treatment of 1-(adamantyloxy)imidazole 3-oxides with Raney-Ni afforded the corresponding imidazole derivatives without cleavage of the N(1)–O bond. Finally, the O-alkylation reactions of the new

• -heterocycles, N-oxides 1 cannot be prepared via oxidation of the parent imidazoles by treatment with an oxidizing agent, e.g., with a percarboxylic acid [6]. Imidazole N-oxides are versatile substrates for the preparation of diverse imidazole derivatives and the most characteristic feature is their 1,3-dipolar

• importance of this procedure is reflected in the multistep reactions applied for the preparation of some bioactive imidazole derivatives [22][23]. However, the preparation of imidazole-2-thiones with N-alkoxy groups, starting with the corresponding 2-unsubstituted imidazole 3-oxides, has not yet been

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• , triazolo[1,2-a]indazoletrione derivatives, tetrasubstituted imidazole derivatives, aromatic/aliphatic sulfide derivatives, and N-substituted pyrrole derivatives. These catalysts were used in cellulose hydrolysis, cellobiose hydrolysis, production of fatty acid ethyl ester, the transesterification of

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• photoredox-generated thiocyanate radical can add to the heteroaromatic system, which subsequently rearomatizes via deprotonation. This method was suitable for substituted imidazoheterocycles, bearing electron-donating and withdrawing groups. Other imidazole derivatives were unreactive under the reported

Reactivity of bromoselenophenes in palladium-catalyzed direct arylations

• Aymen Skhiri,
• Ridha Ben Salem,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2017, 13, 2862–2868, doi:10.3762/bjoc.13.278

• allowed the coupling of several heteroaromatics such as thiazole, pyrrole, furan or imidazole derivatives with aryl bromides [36]. 2-Bromoselenophene, which was easily prepared by reaction of selenophene with N-bromosuccinimide [37], and 2-ethyl-4-methylthiazole were employed as model substrates for our

A novel synthetic approach to hydroimidazo[1,5-b]pyridazines by the recyclization of itaconimides and HPLC–HRMS monitoring of the reaction pathway

• Dmitry Yu. Vandyshev,
• Khidmet S. Shikhaliev,
• Andrey Yu. Potapov,
• Michael Yu. Krysin,
• Fedor I. Zubkov and
• Lyudmila V. Sapronova

Beilstein J. Org. Chem. 2017, 13, 2561–2568, doi:10.3762/bjoc.13.252

• -addition by the activated C=C double bond and subsequent intramolecular recyclization of the intermediate with the amino group involved. Keywords: cascade reaction; diaminoimidazoles; HPLC–HRESIMS; imidazo[1,5-b]pyridazines; itaconimides; Introduction Among the numerous bicyclic fused imidazole

• derivatives, there is great interest in imidazo[1,5-annelated]diazines due to their diverse pharmacological actions and bioisosterism with imidazo[4,5-d]pyrimidines (purines). The presence of a bridgehead nitrogen atom is a common structural motif of these heterocyclic systems. For example, compounds with the

Sequential decarboxylative azide–alkyne cycloaddition and dehydrogenative coupling reactions: one-pot synthesis of polycyclic fused triazoles

• Kuppusamy Bharathimohan,
• Thanasekaran Ponpandian,
• A. Jafar Ahamed and
• Nattamai Bhuvanesh

Beilstein J. Org. Chem. 2014, 10, 3031–3037, doi:10.3762/bjoc.10.321

• phenylacetylene instead of phenylpropiolic acid and the product 4a was isolated in 79% yield (Scheme 2). This result clearly shows that the use of 2-alkynoic acid is more advantageous for this reaction. The 1-(2-azidophenyl)-1H-imidazole derivatives 1b and 1c also participates effectively in the optimized

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• . Among the other basic chemicals that are used in significantly large quantities are a large number of organic molecules, e.g., nitrobenzenes, nitrophenols, nitrotoluenes, nitroxylenes, nitronaphthalenes, nitrohaloaromatics, nitroanilines, nitrotoluidines, imidazole derivatives, nitroketones, pyridine

1-n-Butyl-3-methylimidazolium-2-carboxylate: a versatile precatalyst for the ring-opening polymerization of ε-caprolactone and rac-lactide under solvent-free conditions

• Astrid Hoppe,
• Faten Sadaka,
• Claire-Hélène Brachais,
• Gilles Boni,
• Jean-Pierre Couvercelle and
• Laurent Plasseraud

Beilstein J. Org. Chem. 2013, 9, 647–654, doi:10.3762/bjoc.9.73

• (DMC) with imidazole derivatives, making them very attractive and accessible compounds [35]. Therefore, they found applications as ligands in organometallic catalysis [36][37][38][39][40][41], as precursors of halide-free ionic liquids [42][43][44][45], and as organocatalysts in reactions involving

Enantioselective reduction of ketoimines promoted by easily available (S)-proline derivatives

• Martina Bonsignore,
• Maurizio Benaglia,
• Laura Raimondi,
• Manuel Orlandi and
• Giuseppe Celentano

Beilstein J. Org. Chem. 2013, 9, 633–640, doi:10.3762/bjoc.9.71

• -established methodology to perform enantioselective reductions of carbon nitrogen double bonds [1]. In the past decade different classes of enantiomerically pure Lewis bases have been developed, including N-formyl derivatives, oxazolines, imidazole derivatives, sulfonamides and picolinamides [2][3]. Some of

A quantitative approach to nucleophilic organocatalysis

• Herbert Mayr,
• Sami Lakhdar,
• Biplab Maji and
• Armin R. Ofial

Beilstein J. Org. Chem. 2012, 8, 1458–1478, doi:10.3762/bjoc.8.166

• atom in the benzothiazole by a NCH3 group (55b → 55c) shows that imidazole derivatives are approximately four orders of magnitude more reactive than structurally analogous thiazole derivatives, which can, again, be assigned to the different electronegativities of sulfur and nitrogen. Conclusion

Self-assembly of Ru₄ and Ru₈ assemblies by coordination using organometallic Ru(II)₂ precursors: Synthesis, characterization and properties

• Sankarasekaran Shanmugaraju,
• Dipak Samanta and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2012, 8, 313–322, doi:10.3762/bjoc.8.34

• diffraction data. Though the formation of discrete structures from pyridyl donors has been well established, the quantitative formation of 2a, 2b and 2c from an imidazole-type donor is new and suggests the feasibility of using imidazole derivatives as potential building units. The lengths of 1a and 1b fit

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• corresponding quinoid structure (2H-imidazole derivatives), as shown in Scheme 3 [19][59][60][61]. In 1999, Ye et al. [61] reported the oxidation of D-π-A diimidazole 27a to quinoid 34 and a comparison of the linear and nonlinear optical properties. Partially planarized quinoid 34 (μ = 19.0 D; β of 205.7 × 10

• -photon absorbing molecules with blue upconversion fluorescence [68]. These imidazole derivatives proved to be potent two-photon absorbing molecules with TPA cross-section δ up to 20.65 GM at 800 nm. The molecular structure of chromophore 60 was also confirmed by X-ray analysis. Similar derivatives 61

• moiety may behave as an electron acceptor or donor. Taking our series of structurally similar chromophores 21–26 and 88–93 as an example, which primarily differ in the orientation of the substituents along the imidazole ring, C4/C5 donor-substituted imidazole derivatives showed higher nonlinearities

Michael-type addition of azoles of broad-scale acidity to methyl acrylate

• Sławomir Boncel,
• Kinga Saletra,
• Barbara Hefczyc and
• Krzysztof Z. Walczak

Beilstein J. Org. Chem. 2011, 7, 173–178, doi:10.3762/bjoc.7.24

• , no corresponding regioisomers were obtained. Keywords: imidazole derivatives; methyl acrylate; Michael-type addition; pyrazole derivatives; 1,2,4-triazole derivatives; Introduction Derivatives of azoles are important biologically active compounds. Many, especially those containing imidazole

Synthesis of some novel hydrazono acyclic nucleoside analogues

• Mohammad N. Soltani Rad,
• Ali Khalafi-Nezhad and
• Somayeh Behrouz

Beilstein J. Org. Chem. 2010, 6, No. 49, doi:10.3762/bjoc.6.49

• that among published methods for N-alkylation of imidazole derivatives [26][27][28][29][30][31][32][33][34], the method developed by Liu et al. [35] was the most appropriate one for N-alkylation of azoles and their derivatives, since in this method the formation of quaternary imidazolium salts is

• , we have synthesized novel acyclic nucleosides 2a–2o containing a miconazole-like scaffold as well as hydrazone moiety. In this series of acyclic nucleosides, we employed various nucleobases and other imidazole derivatives in place of the imidazole in miconazole. To interpret the dominant formation of