Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• distorted structures can be obtained and their intrinsic properties investigated, and on the other hand, with a subtle choice of the chalcogen element and its oxidation state, controlled extrusion coupled to 7-membered ring contraction will lead to planar benzenoid π-CPCs in situ, in response to diverse

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• helical bilayer, non-benzenoid nanographene 58 which contains a [10]helicene with two embedded heptagons as a novel chiral moiety (Scheme 11). By using the same intermediate 43, the iodine-NG 101 together with NG 44 was obtained in a 22% yield. Then compound 101 was coupled with 4-tert

The ethoxycarbonyl group as both activating and protective group in N-acyl-Pictet–Spengler reactions using methoxystyrenes. A short approach to racemic 1-benzyltetrahydroisoquinoline alkaloids

• Marco Keller,
• Karl Sauvageot-Witzku,
• Franz Geisslinger,
• Nicole Urban,
• Michael Schaefer,
• Karin Bartel and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2716–2725, doi:10.3762/bjoc.17.183

• activation by TPC2-A1-P is better targetable than by TPC2-A1-N. This result is in accordance with our previous observations that TPC2-blocking activity is only observed for monomeric benzyltetrahydroisoquinolines if they are decorated with aromatic residues, which imitate the two benzenoid rings of the

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• -containing homo- and copolymers, including brief descriptions of their key properties. Keywords: azulene; chemical synthesis; copolymer; non-alternant hydrocarbon; organic electronics; polyazulene; Introduction Azulene (C10H8) is a non-alternant, non-benzenoid, 10 π electron aromatic hydrocarbon containing

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• treatment with ferrocyanide. A Cu powder-mediated reduction gives the N-protected bis(indol-2-yl)tellane 147. The final desulfonated product 148 is a potent thiol peroxidase reducing agent [100]. The benzenoid C4 and C7 linkages The syntheses of bisindolyl non-metallides connected through benzenoid rings of

• review summarizes the various (un)catalytic synthetic techniques of the symmetric and unsymmetric bis/tris(indolyl)-containing non-metallides consisting of multiple indole molecules covalently connected via C2, C3 (pyrrole ring) and C4–C7 (benzenoid ring) by different central atoms. Like the bis(indolyl

Regioselective N-alkylation of the 1H-indazole scaffold; ring substituent and N-alkylating reagent effects on regioisomeric distribution

• Ryan M. Alam and
• John J. Keating

Beilstein J. Org. Chem. 2021, 17, 1939–1951, doi:10.3762/bjoc.17.127

• indazole core facilitated excellent N-2 regioselectivity under conditions A (Table 4, entries 3 and 4). To further examine the positional effect of benzenoid ring substitution on N-alkylation regioselectivity, 6-, 5-, and 4-CO2Me substituted indazole derivatives were alkylated, under conditions A and B

• , solvent, and temperature.a Indazole C-3 substituent effects. Effect of NaH and THF on N-1 regioselectivity.a Effect of indazole benzenoid ring substituents on N-1:N-2 regioselectivity.a Effect of 15-crown-5 on the regioselective N-alkylation of indazole 9, in the presence of NaH in THF.a Alkylating

Synthesis of 4-amino-5-fluoropyrimidines and 5-amino-4-fluoropyrazoles from a β-fluoroenolate salt

• Tobias Lucas,
• Jule-Philipp Dietz and
• Till Opatz

Beilstein J. Org. Chem. 2020, 16, 445–450, doi:10.3762/bjoc.16.41

• products. Subsequently, benzamidine derivatives with a broad variety of substituents on the benzenoid core were evaluated as the nucleophiles. Benzamidine hydrochloride itself yielded compound 10h with an excellent yield of 93%. A variety of substituted products including electron-donating (compounds 10i–k

Design, synthesis and spectroscopic properties of crown ether-capped dibenzotetraaza[14]annulenes

• Krzysztof M. Zwoliński and
• Julita Eilmes

Beilstein J. Org. Chem. 2019, 15, 617–622, doi:10.3762/bjoc.15.57

• ], little research has been undertaken regarding DBTAAs functionalized with crown ether moieties (see Figure 1). Kruse and Breitmaier [24] reported annulated DBTAA‘s containing benzo-15-crown-5 scaffolds fused with benzenoid rings of the macrocyclic core. Both nickel(II) and cobalt(II) complexes were

Correction: Varioloid A, a new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291

• Peng Zhang,
• Xiao-Ming Li,
• Xin-Xin Mao,
• Attila Mándi,
• Tibor Kurtán and
• Bin-Gui Wang

Beilstein J. Org. Chem. 2018, 14, 2394–2395, doi:10.3762/bjoc.14.215

• benzenoid derivatives; cytotoxicity; marine alga-derived fungus; Paecilomyces variotii; TDDFT-ECD calculation; The authors wish to rename compounds 1 and 2 (shown in Figure 1 of the original article [1]) as varioloids C and D, respectively (Figure 1), as the synonyms varioloids A and B have already been

Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine

• Piotr Pomarański,
• Piotr Roszkowski,
• Jan K. Maurin,
• Armand Budzianowski and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2018, 14, 2384–2393, doi:10.3762/bjoc.14.214

• , Tanaka presented an atropselective synthesis of axially chiral all-benzenoid biaryls by gold-catalysed intramolecular hydroarylation of alkynones to give the desired atropisomeric product with a good ee value of 70% [26]. Conventional approaches to the synthesis of biaryl compounds having axial chirality

One hundred years of benzotropone chemistry

• Arif Dastan,
• Haydar Kilic and
• Nurullah Saracoglu

Beilstein J. Org. Chem. 2018, 14, 1120–1180, doi:10.3762/bjoc.14.98

• . Benzotropolones Benzannulation to the tropolone scaffold can give numerous tautomeric hydroxybenzotropones or benzotropolenes. Figure 10 shows 238A (or 241A–240) as single tautomers, whereas 239 and 174 are depicted as a mixture of tautomers. Moreover, benzenoid structures as 238A are more stable than o-quinoidal

Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity

• Tathagata Mukherjee,
• Soumik Biswas,
• Andreas Ehnbom,
• Subrata K. Ghosh,
• Ibrahim El-Zoghbi,
• Nattamai Bhuvanesh,
• Hassan S. Bazzi and
• John A. Gladysz

Beilstein J. Org. Chem. 2017, 13, 2486–2501, doi:10.3762/bjoc.13.246

• powder in 89% yield. This material was stable at room temperature and gave a microanalysis consistent with a monohydrate. Hence, the iodine atom in benzenoid compounds with two Rf8CH2CH2 substituents is sufficiently Lewis basic to support a dichloride, but analogs with two Rf6 substituents are not

Synthesis and optical properties of new 5'-aryl-substituted 2,5-bis(3-decyl-2,2'-bithiophen-5-yl)-1,3,4-oxadiazoles

• Anastasia S. Kostyuchenko,
• Tatyana Yu. Zheleznova,
• Anton J. Stasyuk,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2017, 13, 313–322, doi:10.3762/bjoc.13.34

• ). Moderate to large values of Stokes shifts are observed for compounds 15b–g originating from bond order switching (benzenoid to quinoid) in the excited state. Moderate values of Stokes shifts (0.52–0.63 eV) are observed for 15b–e and the Stokes shift increases with an increase of the aryl substituent size

Varioloid A, a new indolyl-6,10b-dihydro-5aH-[1]benzofuro[2,3-b]indole derivative from the marine alga-derived endophytic fungus Paecilomyces variotii EN-291

• Peng Zhang,
• Xiao-Ming Li,
• Xin-Xin Mao,
• Attila Mándi,
• Tibor Kurtán and
• Bin-Gui Wang

Beilstein J. Org. Chem. 2016, 12, 2012–2018, doi:10.3762/bjoc.12.188

• varioloid B (2). Both compounds 1 and 2 exhibited cytotoxicity against A549, HCT116, and HepG2 cell lines, with IC50 values ranging from 2.6 to 8.2 µg/mL. Keywords: bisindolyl benzenoid derivatives; cytotoxicity; marine alga-derived fungus; Paecilomyces variotii; TDDFT-ECD calculation; Introduction The

• cyclized bisindolyl benzenoid derivatives (compounds 1 and 2) (Figure 1). The rare planar structure of compound 2 was previously reported but the full NMR data were not disclosed and the relative and absolute configuration had not been determined [13]. Herein we describe the isolation, structural

• one isolated sp3-methine proton (δH 6.42, H-2), which were unambiguously designated by the HSQC experiment. A comprehensive analysis of the COSY spectrum (Figure 2) revealed the existence of two 1,2-disubstituted benzenoid rings (sequential COSY correlations from H-4 to H-7 and from H-4’ to H-7

SmI₂-mediated dimerization of indolylbutenones and synthesis of the myxobacterial natural product indiacen B

• Nils Marsch,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2015, 11, 1700–1706, doi:10.3762/bjoc.11.184

• not effect any reaction, as we learned when trying to dimerize the natural product verticillatine B (20) from the Brazilian plants Borreria verticillata and Raputia simulans [2][3]. We had speculated on the participation of the benzenoid double bond in dimerization reactions which would have

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• oligomers with radially expanded structures can be expected to demonstrate multifunctional properties because a central core and TTF branches exhibit individual and/or cooperative functionalities [25]. For example, dendrimers composed of central benzenoid cores and TTF branches are cited as representative

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

Bis(vinylenedithio)tetrathiafulvalene analogues of BEDT-TTF

• Erdal Ertas,
• İlknur Demirtas and
• Turan Ozturk

Beilstein J. Org. Chem. 2015, 11, 403–415, doi:10.3762/bjoc.11.46

• reported in 2013 [58]. Their syntheses began with our standard synthesis of a 1,8-diketone 74 having a thiophene in place of a benzenoid aromatic group (Scheme 11). Reaction of the zinc-complex 59 with four mol equivalents of α-bromoketone 72 gave the diketone 74 in 80% yield, subsequent ring closure of

Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

• Anastasia S. Kostyuchenko,
• Vyacheslav L.Yurpalov,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2014, 10, 1596–1602, doi:10.3762/bjoc.10.165

• reconstruction takes place upon their optical excitation, the dominant reason being the bond order switching accompanying the benzenoid–quinoid transition. Small differences in the magnitude of this shift are observed arranging in a sequence 15 > 18 > 13 ≈ 14, and scaling well with the atomic radii of the azole

Aza-Diels–Alder reaction between N-aryl-1-oxo-1H-isoindolium ions and tert-enamides: Steric effects on reaction outcome

• Amitabh Jha,
• Ting-Yi Chou,
• Zainab ALJaroudi,
• Bobby D. Ellis and
• T. Stanley Cameron

Beilstein J. Org. Chem. 2014, 10, 848–857, doi:10.3762/bjoc.10.81

• more reactive as the resonance forms of the putative intermediate retain benzenoid character of one aromatic ring [41]. Another observation that further supports the inverse-electron demand aza-Diels–Alder mechanism is the diastereoselectivity shown in these reactions. All compounds in series 1 and 2

Gold-catalyzed cyclization of allenyl acetal derivatives

• Dhananjayan Vasu,
• Samir Kundlik Pawar and
• Rai-Shung Liu

Beilstein J. Org. Chem. 2013, 9, 1751–1756, doi:10.3762/bjoc.9.202

• desired 6b in 96% yield. The reaction worked also with 5c and 5d bearing a cyclohexyl bridge, delivering the desired products 6c and 6d in 78% and 72% yields, respectively (Table 3, entries 2 and 3). We tested the reaction with the benzenoid substrates 5e–5g, giving the corresponding enones 6e–6g in 63–78

Selectivity in C-alkylation of dianions of protected 6-methyluridine

• Ngoc Hoa Nguyen,
• Christophe Len,
• Anne-Sophie Castanet and
• Jacques Mortier

Beilstein J. Org. Chem. 2011, 7, 1228–1233, doi:10.3762/bjoc.7.143

• Li2CuCl4 [16][17][18] to 11 followed by quenching with 4-bromobut-1-ene failed to produce 3a. Consequently, lateral lithiations were examined. Lateral lithiation of benzenoid aromatics requires a stabilizing group capable of either delocalizing negative charge or stabilizing an organolithium by

A simple and convenient one-pot synthesis of substituted isoindolin-1-ones via lithiation, substitution and cyclization of N'-benzyl-N,N-dimethylureas

• Keith Smith,
• Gamal A. El-Hiti,
• Amany S. Hegazy and
• Benson Kariuki

Beilstein J. Org. Chem. 2011, 7, 1219–1227, doi:10.3762/bjoc.7.142

• -benzylbenzamides gives intermediates that cyclise to form de-aromatised species. Oxidation to re-aromatise the benzenoid system, followed by treatment with trifluoroacetic acid to remove the tert-butyl group, gives the corresponding isoindolin-1-ones (Scheme 2) [45]. However, this approach gives more modest yields

Functionalization of anthracene: A selective route to brominated 1,4-anthraquinones

• Kiymet Berkil Akar,
• Osman Cakmak,
• Orhan Büyükgüngör and
• Ertan Sahin

Beilstein J. Org. Chem. 2011, 7, 1036–1045, doi:10.3762/bjoc.7.118

• substitution; Introduction Our sustained interest in benzenoid aromatic compounds with high bromine content has led to the development of a regio- and stereoselective bromination method for aromatic compounds. Recently, we demonstrated the selective bromination of 9,10-dibromoanthracene (1) to give

A new and facile synthetic approach to substituted 2-thioxoquinazolin-4-ones by the annulation of a pyrimidine derivative

• Nimalini D. Moirangthem and
• Warjeet S. Laitonjam

Beilstein J. Org. Chem. 2010, 6, 1056–1060, doi:10.3762/bjoc.6.120

• Nimalini D. Moirangthem Warjeet S. Laitonjam Department of Chemistry, Manipur University, Canchipur 795 003, Manipur, India 10.3762/bjoc.6.120 Abstract A new and facile synthesis of 2-thioxoquinazolin-4-ones by introducing a benzenoid system in the pyrimidine moiety by reacting ethoxymethylene

• derivatives of 1,3-diarylthiobarbituric acids (DTBA) with active methylene compounds, such as malononitrile and ethyl cyanoacetate, in presence of ZnCl2 has been developed. Keywords: benzenoid; ethylcyanoacetate; malononitrile; pyrimidine; 2-thioxoquinazolin-4-ones; Introduction Quinazolines and derivatives