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

• pyridine-3,5-carbonitriles 6–9 were synthesized starting with 4-bromobenzaldehyde (1) (Scheme 1 and Scheme 2). Thus, piperidinium 3,5-dicyano-6-hydroxy-4-(4-bromophenyl)pyridin-2-olate (2) was prepared by cyclocondensation of 1 with cyanoacetamide in methanol in the presence of piperidine. The conversion

• /V∙s at the electric field of 8.1 × 105 V/cm (Figure 8). Conclusion Synthetically convenient protocols for the preparation of sophisticated pyridine-3,5-carbonitriles containing carbazole substituents in positions 2 and 6 were developed starting with 4-bromobenzaldehyde. The compounds were found to

Nucleophile-induced ring contraction in pyrrolo[2,1-c][1,4]benzothiazines: access to pyrrolo[2,1-b][1,3]benzothiazoles

• Ekaterina A. Lystsova,
• Maksim V. Dmitriev,
• Andrey N. Maslivets and
• Ekaterina E. Khramtsova

Beilstein J. Org. Chem. 2023, 19, 646–657, doi:10.3762/bjoc.19.46

• ] and reactions of 3-acyl-2,3-dihydro-1,3-benzothiazole-2-carbonitriles with acetylenedicarboxylate (Scheme 1, entry 9) [4]. The second group of approaches to the PBTA scaffold is an annulation of o-aminothiophenol with a pyrrolothiazole moiety (Scheme 2). It includes catalytic cascade reactions of o

Derivatives of benzo-1,4-thiazine-3-carboxylic acid and the corresponding amino acid conjugates

• Péter Kisszékelyi,
• Tibor Peňaška,
• Klára Stankovianska,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 1195–1202, doi:10.3762/bjoc.18.124

• , three-component procedure was also explored for the preparation of 3-aryl-4H-benzo-1,4-thiazin-2-amines [18]. 3-Aryl- and 3-alkyl-4H-benzo[b][1,4]thiazine-4-carbonitriles 2 (Figure 1) were synthesized in high yield from the corresponding 2-aminobenzothiazoles using the copper–organic framework Cu–MOF-74

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

• synthetically and successful syntheses of different manifold isomers. 3,6-Dihydro-4H-pyrazolo[3,4-d][1,2,3]triazin-4-ones 2, as one example of the diverse compound class, can be gained via diazotization of 3-amino-1H-pyrazole-4-carboxamides 1a or 3-amino-1H-pyrazole-4-carbonitriles 1b and subsequent cyclization

• the starting 3-amino-1H-pyrazole-4-carboxamides 1a or 3-amino-1H-pyrazole-4-carbonitriles 1b is altered [26]. Furthermore, several 2,7-dihydro-3H-imidazo[1,2-c]pyrazolo[4,3-e][1,2,3]triazines 4 were described. However, while 3,6-substituted-3,6-dihydro-4H-pyrazolo[3,4-d][1,2,3]triazin-4-ones 2 and 3,7

• -pyrazole-4-carbonitriles 1b [22]. Synthesis of 3,4-dihydrobenzo[d][1,2,3]triazine derivatives 8 from triazene-containing precursors 7 [37]. Planned retrosynthesis to obtain 4,6-dihydropyrazolo[3,4-d][1,2,3]-3H-triazines 5 and 4,7-dihydropyrazolo[3,4-d][1,2,3]-3H-triazines 6 from pyrazolylamines 16. DIPA

Synthesis of 3(2)-phosphonylated thiazolo[3,2-a]oxopyrimidines

• Ksenia I. Kaskevich,
• Anastasia A. Babushkina,
• Vladislav V. Gurzhiy,
• Dmitrij M. Egorov,
• Nataly I. Svintsitskaya and
• Albina V. Dogadina

Beilstein J. Org. Chem. 2020, 16, 1947–1954, doi:10.3762/bjoc.16.161

• the formation of 5- and 7-oxothiazolopyrimidine-6-carbonitriles (Scheme 1) [12][13]. The synthesis of thiazolopyrimidines through the reaction of 2-aminothiazoles with 1,3-ketoesters in the presence of acids, bases or condensing agents (Scheme 2) has been studied fairly well [6][8][14][15][16]. The

• uracil ring, leading to the formation of 7-oxopyrimidines. Structure of ritanserin and setoperone drugs. One-pot synthesis of 5(7)-oxothiazolopyrimidine-6-carbonitriles. Synthesis of thiazolopyrimidine-5-ones through the reaction of 2-aminothiazoles with ethyl acetoacetate. Synthesis of 2-(benzo[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

• a reactant in the reaction with 3-substituted-5-aminopyrazole-4-carbonitriles (R = H, CH3) 1a/b and aromatic aldehydes 2a–f (ultrasonication in acetic acid at room temperature for 120 min). In this case, the corresponding ethyl 3-cyano-7-((4-cyano-3-substituted-1H-pyrazol-5-yl)amino)-2-substituted-5

• (Figure 3). Conclusion In this study we disclosed a new direction for the multicomponent reaction of 5-aminopyrazole-4-carbonitriles or 3-amino-1,2,4-triazole with pyruvic acid or ethyl pyruvate and aromatic aldehydes under ultrasonication, leading to 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-a

Multicomponent reactions (MCRs): a useful access to the synthesis of benzo-fused γ-lactams

• Edorta Martínez de Marigorta,
• Jesús M. de Los Santos,
• Ana M. Ochoa de Retana,
• Javier Vicario and
• Francisco Palacios

Beilstein J. Org. Chem. 2019, 15, 1065–1085, doi:10.3762/bjoc.15.104

• also been performed by using scandium catalyst (Sc(OTf)3, 2.5 mol %) and starting from ester 29. Under these conditions, not only benzyl or alkyl, but also a wide range or ortho-, meta- and para-arylamines 2 can be used at room temperature to make 3-oxoisoindolinone-1-carbonitriles 53a in very good

Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-c]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds

• Victoria V. Lipson,
• Tetiana L. Pavlovska,
• Nataliya V. Svetlichnaya,
• Anna A. Poryvai,
• Nikolay Yu. Gorobets,
• Erik V. Van der Eycken,
• Irina S. Konovalova,
• Svetlana V. Shiskina,
• Alexander V. Borisov,
• Vladimir I. Musatov and
• Alexander V. Mazepa

Beilstein J. Org. Chem. 2019, 15, 1032–1045, doi:10.3762/bjoc.15.101

• -arylpropanoic acids. The interaction of 2-amino-4-arylimidazoles with aromatic aldehydes or isatins and acyclic methylene active compounds has led to the formation of pyrrolo[1,2-c]imidazole-6-carbonitriles, pyrrolo[1,2-с]imidazole-6-carboxylates and spiro[indoline-3,7'-pyrrolo[1,2-c]imidazoles], which can be

• obtained. The reaction was complete to form a mixture of pyrrolo[1,2-c]imidazol-6-carbonitriles 13 and their azomethine derivatives 14 (Scheme 4). The use of a double excess of aromatic aldehydes 2 in this condensation prevented the formation of a mixture of substances and led to the formation of

• individual 5-amino-3-(arylidenamino)-1-aryl-7-aryl-7H-pyrrolo[1,2-c]imidazole-6-carbonitriles 14, as well as azomethines 16 in case of using ethyl 2-cyanoacetate 15 as the acyclic methylene active compound (Table 3). The isolated products 14a–f and 16a,b were characterized by IR, 1H, 13C NMR and mass

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

• ]. Recently we reported the synthesis of pyridine/benzo-fused cyclododecanes through a four-component tandem reaction [70]. In continuation we herein report the synthesis of novel indole substituted cycloalkyl[b]pyridine-3-carbonitriles from a one-pot six-step tandem protocol involving 3-(1H-indol-3-yl)-3

• –cyclododeca[b]pyridine-3-carbonitriles 7 with ortho/ortho-para/ortho-meta substituted phenyl ring at C-4, exhibited axial chirality. For instance, in the case of 7f with p-Cl substituted phenyl ring at C-4, the 5- and 14-CH2 protons appeared as triplets at 2.56 and 3.01 ppm, respectively. However, in 7l

• –cyclododeca[b]pyridine-3-carbonitriles 12 (Table 3). These experiments were repeated thrice in order to ascertain the exclusive formation of 12. The structure of 12 was confirmed from the 1H NMR spectra, wherein the characteristic singlet around 4.6–5.1 ppm due to the 4-CH proton was observed. In addition, in

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

• an antibiotic [94]. In this methodology, N-(p-hydroxyphenyl)cyanoacetamides 65 were cyclized to corresponding 4-spiro-β-lactam-3-carbonitriles 66 in useful yields using PIDA (15) as an electrophile in the presence of KOH as base in anhydrous ethanol at room temperature (Scheme 22). In 2014, Fan and

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• protic solvents such as H2O or EtOH at 100 °C, the desired products were formed in short reactions (1–20 min) and chromene-2-carbonitriles 12–15 were isolated in 61–88% yields. Saito et al. generated o-QMs starting from Mannich bases by low-energy UV irradiation in aqueous acetonitrile [68]. In the

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

• pyridine to give 1,3,6-trisubstitutedpyrazolo[3,4-b]pyrazine-5-carbonitriles 230 in good yields. 5-Carbonitrilepyrazolo[3,4-b]pyrazines 230 were hydrolyzed to corresponding pyrazolo[3,4-b]pyrazine-5-carboxylic acids 231 and subsequently converted to acid chloride 232 at reflux temperature with thionyl

Ultrasound-promoted organocatalytic enamine–azide [3 + 2] cycloaddition reactions for the synthesis of ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones

• Gabriel P. Costa,
• Natália Seus,
• Juliano A. Roehrs,
• Raquel G. Jacob,
• Ricardo F. Schumacher,
• Thiago Barcellos,
• Rafael Luque and
• Diego Alves

Beilstein J. Org. Chem. 2017, 13, 694–702, doi:10.3762/bjoc.13.68

• short reaction times. In addition, this protocol was extended to β-keto esters, β-keto amides and α-cyano ketones. Selanyltriazoyl carboxylates, carboxamides and carbonitriles were synthesized in high yields at short times of reaction under very mild reaction conditions. Keywords: cycloadditions

• 1,2,3-triazoles [33][34][35][36][37]. Selanyltriazoyl carboxylates, carboxamides, carbonitriles or sulfones were synthesized in good to excellent yields using catalytic amounts of an organocatalyst. Organoselenium compounds are attractive synthetic targets because of their selective reactions [38][39

• selanyltriazoyl carboxylates, with carboxamides and carbonitriles synthesized in high yields and short times of reaction. Experimental General information The reactions were monitored by TLC carried out on Merck silica gel (60 F254) by using UV light as visualizing agent and 5% vanillin in 10% H2SO4 and heat as

One-pot synthesis of 4′-alkyl-4-cyanobiaryls on the basis of the terephthalonitrile dianion and neutral aromatic nitrile cross-coupling

• Roman Yu. Peshkov,
• Elena V. Panteleeva,
• Wang Chunyan,
• Evgeny V. Tretyakov and
• Vitalij D. Shteingarts

Beilstein J. Org. Chem. 2016, 12, 1577–1584, doi:10.3762/bjoc.12.153

• -dioxane fragment (6f). The desired 4'-(ω-substituted-alkyl)-biphenyl-4-carbonitriles 5ab–af formed in these reactions in 44–70% yields depending on the nature of the alkylating reagent 6 (Table 1). It should be noted that alkyl halides containing the above-mentioned functional groups have already been

• ), as well as 4'-methyl-2-cyanobiphenyl (2h). In addition, two new neutral carbonitriles – 2,6-difluorobenzonitrile (2g) and 1-cyanonaphthalene (2i) – were tested as cross-coupling participants and found to react with dianion 12−. Alkylation of intermediate anions 3b–i in all these reactions was

Copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines

• Ya Lin Tnay,
• Gim Yean Ang and
• Shunsuke Chiba

Beilstein J. Org. Chem. 2015, 11, 1933–1943, doi:10.3762/bjoc.11.209

• of Grignard reagents to carbonitriles followed by protonation as one of the methods for in situ generation of N–H ketimines, which were directly subjected to Cu-catalyzed aerobic reactions without further purification [54]. In this way, biaryl N–H ketimines generated from biaryl-2-carbonitriles were

• , the cyano group of carbonitrile 1a is transferred to Grignard reagent 2a to afford p-tolunitrile (5a). Considering the importance of carbonitriles in organic synthesis [56], we postulated that the cyano group transfer from simple carbonitriles onto Grignard reagents could be realized using this

• current transformation toward the synthesis of oxaspirocyclohexadienones 3. Therefore, the reactions of carbonitriles 1b–d were examined under the current best reaction conditions (Table 1, entry 8) using p-tolyl Grignard reagent 2a (Table 2). Carbonitrile 1b, having methyl groups in ortho-positions on

Stereochemistry of ring-opening/cross metathesis reactions of exo- and endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitriles with allyl alcohol and allyl acetate

• Piotr Wałejko,
• Michał Dąbrowski,
• Lech Szczepaniak,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 1893–1901, doi:10.3762/bjoc.11.204

• chromatograms recorded from crude reaction mixtures described in Table 1: a) entry 1 and b) entry 5. Numbering of carbon atoms in cross metathesis products. ROCM reactions of 7-oxanorbornene. Metathesis products of exo- and endo-7-oxabicyclo[2.2.1]hept-5-en-2-carbonitriles (1 and 2) with allyl acetate (3) or

• allyl alcohol (4). The plausible mechanism of the formation of ROCM and ROMP products from exo- or endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitriles 1 or 2. For simplicity of the scheme, the reaction of only exo-stereoisomer 1 as a substrate is presented. Results of ROCM reactions of nitriles 1 and 2

Simple two-step synthesis of 2,4-disubstituted pyrroles and 3,5-disubstituted pyrrole-2-carbonitriles from enones

• Murat Kucukdisli,
• Dorota Ferenc,
• Marcel Heinz,
• Christine Wiebe and
• Till Opatz

Beilstein J. Org. Chem. 2014, 10, 466–470, doi:10.3762/bjoc.10.44

• .10.44 Abstract The cyclocondensation of enones with aminoacetonitrile furnishes 3,4-dihydro-2H-pyrrole-2-carbonitriles which can be readily converted to 2,4-disubstituted pyrroles by microwave-induced dehydrocyanation. Alternatively, oxidation of the intermediates produces 3,5-disubstituted pyrrole-2

• -carbonitriles. Keywords: α-aminonitriles; cyclization; heterocycles; microwave-assisted synthesis; pyrroles; Introduction Heterocycles are the largest class of organic compounds [1]. Among them, pyrroles have a distinguished position in the chemistry of living organisms due to their close biogenetic

• closure to furnish 3,4-dihydro-2H-pyrrole-2-carbonitriles 6 after reprotonation [36]. If the products are devoid of an additional substituent in 2-position, the cyclocondensation can be simply effected by refluxing a mixture of the enone 1 and aminoacetonitrile hydrochloride (2) in pyridine. The base

A Lewis acid-promoted Pinner reaction

• Dominik Pfaff,
• Gregor Nemecek and
• Joachim Podlech

Beilstein J. Org. Chem. 2013, 9, 1572–1577, doi:10.3762/bjoc.9.179

• Dominik Pfaff Gregor Nemecek Joachim Podlech Institut für Organische Chemie, Karlsruher Institut für Technologie (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany 10.3762/bjoc.9.179 Abstract Carbonitriles and alcohols react in a Lewis acid-promoted Pinner reaction to carboxylic esters. Best

• results are obtained with two equivalents of trimethylsilyl triflate as Lewis acid. Good yields are achieved with primary alcohols and aliphatic or benzylic carbonitriles, but the straightforward synthesis of acrylates and benzoates starting with acrylonitrile and benzonitrile, respectively, is similarly

• possible. Phenols are not acylated under these reaction conditions. The method has been used for the first total synthesis of the natural product monaspilosin. In the reaction of benzyl alcohols variable amounts of amides are formed in a Ritter-type side reaction. Keywords: carbonitriles; carboxylic

Simple synthesis of pyrrolo[3,2-e]indole-1-carbonitriles

• Adam Trawczyński,
• Robert Bujok,
• Zbigniew Wróbel and
• Krzysztof Wojciechowski

Beilstein J. Org. Chem. 2013, 9, 934–941, doi:10.3762/bjoc.9.107

• procedure for the transformation of 5-nitroindol-4-ylacetonitriles into pyrrolo[3,2-e]indole-1-carbonitriles 6 bearing an additional electron-withdrawing substituent at position 2. In our approach the starting material was 1-benzyloxymethyl-4-cyanomethyl-2-methyl-5-nitroindole (4) obtained via the VNS of

Direct alkenylation of indolin-2-ones by 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles: a novel approach

• Sandeep Kumar,
• Ramendra Pratap,
• Abhinav Kumar,
• Brijesh Kumar,
• Vishnu K. Tandon and
• Vishnu Ji Ram

Beilstein J. Org. Chem. 2013, 9, 809–817, doi:10.3762/bjoc.9.92

• , Lucknow-226001, India 10.3762/bjoc.9.92 Abstract A direct one-pot base-induced alkenylation of indolin-2-ones has been developed by using 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles. Different bases such as MeONa, NaH and t-BuONa have been used to optimize the reaction conditions to obtain the

• ; 2H-pyran-2-one; Introduction 6-Aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles have emerged as versatile synthons for the construction of an array of arenes and heteroarenes through base-induced ring transformation by nitrogen, sulfur and carbon nucleophiles [1]. However, suitably functionalized 2H

• -carbonitriles 3, we envisioned their use to alkenylate indolin-2-ones to deliver 3-alkenylindolin-2-ones. An extensive literature survey revealed that 6-aryl-4-methylthio-2H-pyran-2-one-3-carbonitriles 3 have never been employed to alkenylate indolin-2-ones. Results and Discussion Synthesis Herein, we report a

3-Pyridylnitrene, 2- and 4-pyrimidinylcarbenes, 3-quinolylnitrenes, and 4-quinazolinylcarbenes. Interconversion, ring expansion to diazacycloheptatetraenes, ring opening to nitrile ylides, and ring contraction to cyanopyrroles and cyanoindoles

• Curt Wentrup,
• Nguyen Mong Lan,
• Adelheid Lukosch,
• Pawel Bednarek and
• David Kvaskoff

Beilstein J. Org. Chem. 2013, 9, 743–753, doi:10.3762/bjoc.9.84

• dimethylpyrimidine-carbonitriles [38][39] by adaptation of the literature method [36][37]. 4,6-Dimethyl-2-(5-tetrazolyl)pyrimidine (24): From 3.0 g (22.5 mmol) of 4.6-dimethylpyrimidine-2-carbonitrile was obtained 2.8 g (71%); mp 209–210 °C (dec); 1H NMR (CDCl3) 12.0 (very broad), 7.37 (s, 1H), 2.50 (s, 6H); MS m/z

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• hydrazine, on the other hand, led to 5-aryl-3-arylamino-1H-pyrazole-4-carbonitriles 36, instead of the 5-aminopyrazole 37, which can be rationalized in terms of the higher reactivity of the carbonyl group of 35 toward hydrazine compared to the cyano group (Scheme 9) [40]. Gao and Lam recently reported a

• -carbonitriles 168 bearing steric and/or electronic constraints at C-5 were also treated with anhydrous hydrazine and the corresponding 3-aminopyrazoles 169 were obtained in varying yields. However, when the substituent at C-5 in isothiazole was a better nucleofuge (e.g., PhO, PhS and Cl), the 5

On the functionalization of benzo[e][2,1]thiazine

• Kirill Popov,
• Tatyana Volovnenko and
• Julian Volovenko

Beilstein J. Org. Chem. 2009, 5, No. 42, doi:10.3762/bjoc.5.42

• Kirill Popov Tatyana Volovnenko Julian Volovenko Organic Chemistry Department, Kiev State University, Kiev, 01033, Ukraine 10.3762/bjoc.5.42 Abstract The reactions of benzo[e][2,1]thiazine-4-chloro-3-carbaldehydes 1 and benzo[e][2,1]thiazine-4-chloro-3-carbonitriles 2 with a number of oxidizing

• -carbaldehydes 1 and benzo[e][2,1]thiazine-4-chloro-3-carbonitriles 2. a: NaBH4 (2.5 equiv), MeOH, 2 h, room temp.; b: SOCl2 (4 equiv), benzene, 3 h, 0 °C to room temp.; c: HBr (50%), 5 h, reflux; d: NaOMe/MeOH, 2 h, reflux; e: HS–(CH2)2–OH (1.5 equiv), K2CO3, 1,4-dioxane, TEA, 2 h, reflux. a: LiAlH4 (4 equiv