Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• -chloro-2-fluorobenzene is known to take place at the C–H bond ortho to the fluorine atom [31]. Consequently, from 1,8-dibromonaphthalene and 1-chloro-2-fluorobenzene, fluoranthene 7 bearing a fluorine substituent at position 7 and a chlorine at position 8 was obtained. 7-Fluorofluoranthene-8-carbonitrile

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• -carbonitrile (4) in 5% yield when the reaction was carried out at room temperature in 1,4-dioxane in the presence of an equivalent amount of TEA (Table 1, entry 1). This result is in contrast to our previous findings where the reaction of compound 1a with sulfonyl azides led to 5-amino-1,2,3-triazole-4-N

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

• evaporation at reduced pressure, the residue was subjected to column chromatography with ethyl acetate, dichloromethane and petroleum ether 1:3:7 (v/v/v) to give pure product for analysis. 1'-Benzoyl-1-benzyl-5-methyl-2-oxo-3'-phenyl-1',4'-dihydrospiro[indoline-3,5'-[1,2]diazepine]-6'-carbonitrile (3a

• at reduced pressure, the residue was subjected to column chromatography with ethyl acetate, dichloromethane, and petroleum ether 1:3.7 (v/v/v) to give pure product for analysis. 1-Benzyl-2-oxo-3'-(p-tolyl)-1'-tosyl-1',4'-dihydrospiro[indoline-3,5'-[1,2]diazepine]-6'-carbonitrile (7a): white solid, 64

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

• of 2 to the corresponding 2,6-dibromo-4-(4-bromophenyl)pyridine-3,5-carbonitrile (3) was carried out by melting of compound 2 with phosphorous oxybromide without any solvent at 170 °C for 1 h in good yield. According to the previously reported procedure [4][5], 2,6-bis(3,6-di-tert-butylcarbazol-9-yl

• )-4-(4-bromophenyl)pyridine-3,5-carbonitrile (4) was obtained by the interaction of 3,6-di-tert-butyl-9H-carbazole with compound 3 in THF/DMF solution. The ethynylphenyl-substituted pyridine 5 was synthesized by Sonogashira coupling of 4 with ethynyltrimethylsilane in the presence of PdCl2(PPh3)2 and

• -carbonitrile (REF) [5]. Absorption spectra of dilute toluene, tetrahydrofuran (THF), and chloroform solutions as well as of the films of compounds 6–9 are shown in Figure 2a,b. The nonstructured low-energy bands at wavelengths of 350–450 nm are well seen in the absorption spectra of 6–9. The wavelengths of

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• Anastasia A. Fesenko Anatoly D. Shutalev N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Ave., 119991 Moscow, Russian Federation 10.3762/bjoc.19.126 Abstract The transformation of 3-[(ethoxymethylene)amino]-1-methyl-1H-pyrazole-4-carbonitrile into the 14

• -2-methyl-2,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-5-amine described by Baraldi et al. [41] using the reaction of 3-[(ethoxymethylene)amino]-1-methyl-1H-pyrazole-4-carbonitrile with excess hydrazine hydrate in EtOH under reflux. However, a pyrazole-fused 1,2,4,8,9,11-hexaazamacrocycle was unexpectedly

• the detailed studies of the hydrazine-promoted transformation of 3-[(ethoxymethylene)amino]-1-methyl-1H-pyrazole-4-carbonitrile (4) or 4-imino-2-methyl-2,4-dihydro-5H-pyrazolo[3,4-d]pyrimidin-5-amine (8) into 2,10-dimethyl-2,8,10,16-tetrahydrodipyrazolo[3,4-e:3',4'-l][1,2,4,8,9,11

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• technique after a synthetic transformation are highlighted in the following section (Scheme 14, Table 3). A continuous flow crystallization was performed using a trisegmented tubular crystallizer (KRAIC) coupled with a catalytic hydration of pyrazine carbonitrile [115]. After passing the reaction setup, the

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

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

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• chromatography with petroleum ether/ethyl acetate 15:1 (v/v) as eluent to give the pure products 8a–m for analysis. rel-(3R,3'R)-1,1''-Dibenzyl-5''-chloro-5'-ethoxy-5-methyl-2,2''-dioxodispiro[indoline-3,2'-furan-3',3''-indoline]-4'-carbonitrile (8a): white solid, 71% yield; mp 175–177 °C; 1H NMR (400 MHz, CDCl3

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

• study, we used 1-methyl-4-(methylsulfanyl)-2,5-dioxo-2,5-dihydro-1H-pyrrole-3-carbonitrile (1) with a methylsulfanyl group as a good leaving group. As shown in Scheme 1, the one-pot reaction of 1 with 2-aminopyridine (2a) proceeded by refluxing in ethanol for 2 h to produce the ring-fused pyridine

• 5 of the pyridine ring (Table 1). On the other hand, the reaction of 1 with 5-bromo-2-aminopyridine (2c) afforded an N-methyl-4-((pyridin-2-yl)amino)-substitued maleimide, 4-((5-bromopyridin-2-yl)amino)-1-methyl-2,5-dioxo-2,5-dihydro-1H-pyrrole-3-carbonitrile (4a), based on an A–D–A system

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• C46H55N4O2S, 727.4040; found, 727.4034. 4,6-Bis(3,6-di-tert-butyl-9H-carbazol-9-yl)-5-methylpyrimidine-2-carbonitrile (4). A mixture of compound 3 (50 mg, 0.069 mmol), NaCN (7.4 mg, 0.151 mmol), and THF (2 mL) was refluxed under stirring for 3.5 h. After completion of the reaction, THF was removed by

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• the designed synthetic route, 3-(3,3-diisopropyltriaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile (15) was synthesized in a first step using the commercially available 3-amino-1H-pyrazole-4-carbonitrile (16). Thus, the aminopyrazole was diazotized in aqueous media using hydrochloric acid and sodium nitrite

• . Diisopropylamine and an aqueous solution of potassium carbonate were added to the in-situ generated diazonium salt according to literature-known protocols [40]. The resulting 3-(3,3-diisopropyltriaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile (15) was used as starting material for the attempts to add different side

• synthesized. Altogether nine derivatives 5a–i were synthesized in five steps starting from the commercially available 3-(3,3-diisopropyltriaz-1-en-1-yl)-1H-pyrazole-4-carbonitrile. The herein given examples were generated by introducing two side-chains, one on the pyrazole core and the other as a side chain

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

• , i.e., to assist in 1,3-prototropic shift. 2.2 Catalysis by chiral pyrrolidine derivatives Chiral pyrrolidine derivatives, such as (S)-proline are widely used as organocatalysts [54][64]. Lee et al. synthesized bromopyrrole alkaloids 107 via aza-Michael addition of 4,5-dibromo-1H-pyrrole-2-carbonitrile

One-step synthesis of imidazoles from Asmic (anisylsulfanylmethyl isocyanide)

• Louis G. Mueller,
• Allen Chao,
• Embarek AlWedi and
• Fraser F. Fleming

Beilstein J. Org. Chem. 2021, 17, 1499–1502, doi:10.3762/bjoc.17.106

• ). Trapping lithiated Asmic with 1-methyl-1H-indole-3-carbonitrile afforded indole 7l whereas trapping with ethyl N-phenylformimidate afforded the selectively N-1 protected imidazole 7m (Scheme 2) [21]. Collectively, the condensations of lithiated Asmic with nitriles or an imidate provides an efficient route

Highly regio- and stereoselective phosphinylphosphination of terminal alkynes with tetraphenyldiphosphine monoxide under radical conditions

• Dat Phuc Tran,
• Yuki Sato,
• Yuki Yamamoto,
• Shin-ichi Kawaguchi,
• Shintaro Kodama,
• Akihiro Nomoto and
• Akiya Ogawa

Beilstein J. Org. Chem. 2021, 17, 866–872, doi:10.3762/bjoc.17.72

• using a radical initiator such as 1,1'-azobis(cyclohexane-1-carbonitrile) (V-40) (Scheme 1a) [45] or upon photoirradiation (Scheme 1b) [38] yields vic-bis(diphenylphosphino)alkenes in good yields. Unfortunately, this photoinduced reaction of Ph2PPPh2 was not applicable to alkenes [42]. To change the

• (X)PPh2 to unsaturated C–C bonds. The addition of Ph2P(O)PPh2 (1) to 1-octyne (2a). Phosphinylphosphination of various terminal alkynes 2 with 1. aIsolated yields. V-40 = 1,1’-azobis(cyclohexane-1-carbonitrile). bRepeated 2 times. Attempted radical addition to internal alkynes and insight into the

[3 + 2] Cycloaddition with photogenerated azomethine ylides in β-cyclodextrin

• Margareta Sohora,
• Leo Mandić and
• Nikola Basarić

Beilstein J. Org. Chem. 2020, 16, 1296–1304, doi:10.3762/bjoc.16.110

• '-Hydroxy-5'-oxo-1',2',5',9b'-tetrahydrospiro[cyclohexane-1,3'-pyrrolo[2,1-a]isoindole]-1'-carbonitrile (7): 2 mg (2%), oily crystals; 1H NMR (CD3OD, 600 MHz) δ 7.81 (dd, J = 1.0, 7.6 Hz, 1H), 7.70 (dt, J = 1.3, 7.6 Hz, 1H), 7.65 (dt, J = 1.3, 7.6 Hz, 1H), 7.48 (dd, J = 1.0, 7.6 Hz, 1H), 4.55 (br s, 3H

• , 1C), 30.1 (t, 1C), 26.2 (t, 1C), 23.7 (t, 1C), 21.3 (t, 1C); MS m/z (% relative intensity): 229 (100), 230 (15.1), 231 (1.1). 1,6-Dioxo-1,4,5,6-tetrahydro-2H-spiro[benzo[c]azocine-3,1'-cyclohexane]-5-carbonitrile (9): 3 mg (3%), oily crystals; 1H NMR (CD3OD, 300 MHz) δ 8.19-8.15 (m, 1H), 8.04–8.00 (m

• –25 min (MeOH), 25–30 min (0−35% H2O/MeOH, 0.1% TFA). 9b'-Methyl-5'-oxo-1',2',5',9b'-tetrahydrospiro[adamantane-2,3'-pyrrolo[2,1-a]isoindole]-1'-carbonitrile (11): 2 mg (2%), oily crystals; 1H NMR (CD3OD, 300 MHz) δ 7.70–7.65 (m, 2H), 7.59 (d, J = 7.6 Hz, 1H), 7.53 (dt, J = 0.6, 7.4 Hz, 1H), 4.03 (d

Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines

• Yana I. Sakhno,
• Maryna V. Murlykina,
• Oleksandr I. Zbruyev,
• Anton V. Kozyryev,
• Svetlana V. Shishkina,
• Dmytro Sysoiev,
• Vladimir I. Musatov,
• Sergey M. Desenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2020, 16, 281–289, doi:10.3762/bjoc.16.27

• Republic 10.3762/bjoc.16.27 Abstract Four-component reactions of 3-amino-1,2,4-triazole or 5-amino-1H-pyrazole-4-carbonitrile with aromatic aldehydes and pyruvic acid or its esters under ultrasonication were studied. Unusual for such a reaction type, a cascade of elementary stages led to the formation of

• 7-azolylaminotetrahydroazolo[1,5-a]pyrimidines. Keywords: 5-amino-1H-pyrazole-4-carbonitrile; 3-amino-1,2,4-triazole; 7-azolylaminotetrahydroazolo[1,5-a]pyrimidines; heterocycle; multicomponent reaction; ultrasonication; Introduction Tetrahydropyrimidines are heterocycles of high pharmacological

• -pyrazole-4-carbonitrile with aromatic aldehydes and pyruvic acid or its esters under ultrasonication led to the formation of 4,5,6,7-tetrahydroazolo[1,5-a]pyrimidines 4a–u (Scheme 4) containing an azolylamino substituent in the 7-position via an unusual pseudo four-component reaction, rather than two

Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives

• Hai-Yun Huang,
• Haoran Li,
• Thierry Roisnel,
• Jean-François Soulé and
• Henri Doucet

Beilstein J. Org. Chem. 2019, 15, 2069–2075, doi:10.3762/bjoc.15.204

• structure of 2 was confirmed by X-ray analysis. A lower yield of 7 was obtained for the reaction of 4-bromobenzaldehyde with lilolidine due to the formation of degradation products. Good yields in 8 and 9 were obtained from 4-chloro- and 4-carbonitrile-substituted aryl bromides. In all cases, with these

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

The LANCA three-component reaction to highly substituted β-ketoenamides – versatile intermediates for the synthesis of functionalized pyridine, pyrimidine, oxazole and quinoxaline derivatives

• Tilman Lechel,
• Roopender Kumar,
• Mrinal K. Bera,
• Reinhold Zimmer and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2019, 15, 655–678, doi:10.3762/bjoc.15.61

• various examples (Table 1, entries 15–19, 26–28, and 34). Even with acrylic acid the expected product KE15 was isolated in 91% yield. Although we did not systematically study nitriles with heterocyclic substituents, we showed that thiophene-2-carbonitrile is an excellent substrate leading to KE32–35 in

• good yields (Table 1, entries 32–35). Unfortunately, pyridine-2-carbonitrile could not be used as electrophilic component; the reason for this failure is unclear. By use of heterocyclic carboxylic acids we could smoothly introduce 2-thienyl and 2-pyridyl substituents into the β-ketoenamides KE2, KE23

Synthesis of indole–cycloalkyl[b]pyridine hybrids via a four-component six-step tandem process

• Muthumani Muthu,
• Rakkappan Vishnu Priya,
• Abdulrahman I. Almansour,
• Raju Suresh Kumar and
• Raju Ranjith Kumar

Beilstein J. Org. Chem. 2018, 14, 2907–2915, doi:10.3762/bjoc.14.269

• condensation–nucleophilic addition to carbonyl–Michael addition–N-cyclization–elimination–air oxidation sequence to afford structurally intriguing indole–cycloalkyl[b]pyridine-3-carbonitrile hybrid heterocycles in excellent yields. Keywords: cycloalkyl[b]pyridine-3-carbonitrile; cyclododecanone; 3-(1H-indol-3

• -oxopropanenitriles, aromatic aldehydes, cycloalkanones and ammonium acetate. This work also stems from our continuous effort in synthesizing novel cycloalkyl[b]pyridine-3-carbonitrile hybrid heterocycles via tandem/domino reaction [71][72]. Results and Discussion Initially the precursors viz. 3-(1H-indol-3-yl)-3

• acetate (6) was chosen as a model in order to identify the optimum conditions for this reaction (Table 1). To begin with, a 1:1:1:2 mixture of the above reactants was refluxed in toluene for 4 h which led to the formation of indole–cyclododeca[b]pyridine-3-carbonitrile 7f and the intermediate (E)-3-(4

Bioinspired cobalt cubanes with tunable redox potentials for photocatalytic water oxidation and CO₂ reduction

• Zhishan Luo,
• Yidong Hou,
• Jinshui Zhang,
• Sibo Wang and
• Xinchen Wang

Beilstein J. Org. Chem. 2018, 14, 2331–2339, doi:10.3762/bjoc.14.208

• ATCN/p-C3N4 sample was synthesized according to the literature procedures [68]. 2-Aminothiophene-3-carbonitrile (ATCN, 10 mg) and 10 g urea were mixed with 10 mL pure water, and stirring at room temperature for 12 h and then stirring at 80 °C to remove water. The mixtures were ground into powder and

Synthesis of spirocyclic scaffolds using hypervalent iodine reagents

• Fateh V. Singh,
• Priyanka B. Kole,
• Saeesh R. Mangaonkar and
• Samata E. Shetgaonkar

Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152

• 2014, Xu and Abdellaoui [93] reported a nucleophilic intramolecular cyclization of phenylacetamides 65 to spirocyclic lactams 66 via iodine(III)-mediated spirocarbocyclizations. In literature, there are limited methods available for the synthesis of spiro-β-lactam-3-carbonitrile which is widely used as

[3 + 2]-Cycloaddition reaction of sydnones with alkynes

• Veronika Hladíková,
• Jiří Váňa and
• Jiří Hanusek

Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113

• , it can be concluded that any substituent in position 4 reduces the regioselectivity. The steric hindrance can also affect the ratio of the regioisomers formed. The classical example was described by Yeh et al. [75][76] who performed reactions of 3-(4-ethoxyphenyl)sydnone-4-carbonitrile with various

5-Aminopyrazole as precursor in design and synthesis of fused pyrazoloazines

• Ranjana Aggarwal and
• Suresh Kumar

Beilstein J. Org. Chem. 2018, 14, 203–242, doi:10.3762/bjoc.14.15

• reported a similar reaction of 5-aminopyrazole 16, arylaldehyde 47 with ethyl cyanoacetate (94) under ultrasound irradiation in presence of p-TSA in water for the synthesis of 3-methyl-6-oxo-4-aryl-4,5,6,7-tetrahydro-4H-pyrazolo[3,4-b]pyridine-5-carbonitrile derivatives 95 (Scheme 27). All the synthesized

• -(2,4-dichlorophenyl)-1H-pyrazol-5-yl)formimidate (216), in turn was obtained by reaction of 5-amino-1-(2,4-dichlorophenyl)-1H-pyrazole-4-carbonitrile (208) with trimethylorthoformate. 4-Amino-1-(2,4-dichlorophenyl)pyrazolo[3,4-d]pyrimidine derivatives 217 were coupled with various carboxylic acids in

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

• heteroarenes in the presence of 2 mol % Pd(OAc)2, KOAc as the base in DMA at 90 °C (Scheme 2). The reaction of 2-isopropyl-4-methylthiazole gave the desired product 2 in 82% yield. Conversely, low yields in the target products 3–5 were obtained for the reactions with thiophene-2-carbonitrile, 2-chlorothiophene

• and 2-pentylthiophene, although complete conversions of 2-bromoselenophene were observed. A similar result was obtained for the reaction with 1-phenylpyrrole. Reactions performed at a higher temperature with thiophene-2-carbonitrile, 2-chlorothiophene afforded 3 and 4 in slightly lower yields

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• and its final cross-coupling reactions (Scheme 1). The construction of the DPP central scaffold 6 was accomplished by a well-known reaction between thiophene-2-carbonitrile and dimethyl succinate in the presence of sodium tert-amylalcoholate generated in situ [32]. The reaction provided 6 with a high