Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• reactions (anthracene (33) and maleic anhydride (34) to the cycloaddition adduct 35 and chromene carbaldehyde 36 and enol ether 37 to the diastereomeric pyrano-chromenes 38), Alder-En reactions (oxomalonate diethyl ester (39) and β-pinene (40) to give the α-pinene derivative 41), and the thermal

• up in an oscillating electromagnetic field because it does not exhibit conductive properties, so it had to be mixed with MagSilicaTM. Several oxidations were performed, including those of anthracene (33), propargyl alcohol 55 and testosterone (57), which proceeded smoothly with 80%, 93%, and 95

DDQ in mechanochemical C–N coupling reactions

• Shyamal Kanti Bera,
• Rosalin Bhanja and
• Prasenjit Mal

Beilstein J. Org. Chem. 2022, 18, 639–646, doi:10.3762/bjoc.18.64

• reacted smoothly with various substituted aldehydes (containing a bromo, fluoro, hydroxy, chloro, ethyl, or methyl group) affording the corresponding products 5b–g with good to excellent yields. Also, 3,4,5-trimethoxy-, 2,4,6-trimethyl-, anthracene-9-yl-, and naphthalene-1-yl-substituted benzaldehydes

Heteroleptic metallosupramolecular aggregates/complexation for supramolecular catalysis

• Prodip Howlader and
• Michael Schmittel

Beilstein J. Org. Chem. 2022, 18, 597–630, doi:10.3762/bjoc.18.62

• to steric impediments at the phenanthroline site will not engage in complexation with a second phenanthroline (see HETPYP concept [85][86]). The concept was probed by using nanorotors [Cu2(55)(60)(X)]2+ as catalyst (10 mol %) for the click reaction of 9-(azidomethyl)anthracene (65) and (prop-2-yn-1

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• anthracene and phthalimide guests with unusual and controllable site-selectivity mediated by organopalladium-coordinated hosts in water (Figure 1) [34]. The water-solubility of the coordinated host traced from its ionic form, and the aqueous reaction conformed with the concept of green chemistry. In previous

• reports of supramolecular host-mediated Diels–Alder reactions of anthracenes, 9,10-adducts bridging the center rings of the anthracene frameworks were generally yielded [35][36][37], which resulted from the high localization of π-electron density at that sites [38]. Besides, these reactions required near

• the 1,4-position of 1. On the other hand, the double bond of 2 hardly interacted with the 9,10-position of 1, because of the steric effect induced by the cage host A. This methodology was also compatible with several other anthracene substrates with different substituents at the 9-position. But when

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• -Alk) and 9-(azidomethyl)anthracene (Az-2) as click components was investigated. The detailed 1H NMR spectrum of the resulting anthracene functional polymer (PCL-Anth) exhibited the characteristic signals of triazole and benzylic protons at 5.5 ppm and 8.70 ppm, respectively (Figure 4a). The obtained

• polymer has similar absorption characteristic to bare anthracene (Figure 4b). The fluorescence spectrum of diluted solution of PCL-Anth in THF excited at λexc = 350 nm showed the characteristic emission bands of the excited (singlet) anthracene at 595, 655, and 725 nm (Figure 4c). These observations

• ]. Product was obtained pale yellow oil, yield 96%. 1H NMR (500 MHz, DMSO-d6) δ 7.43–7.34 (m, 5H, -C6H5), 4.43 (s, 2H, CH2-N3). FTIR: 2108 cm−1. Synthesis of (azidomethyl)anthracene (Az-2) A literature procedure was used [45]. 9-Hydroxymethylanthracene (7.40 mmol, 1 equiv) was added to DCM (50 mL) and cooled

Synthesis and investigation on optical and electrochemical properties of 2,4-diaryl-9-chloro-5,6,7,8-tetrahydroacridines

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 2450–2461, doi:10.3762/bjoc.17.162

• optoelectronic properties [32][35][36][37]. Acridines, as aza-analogues of anthracene have obtained much attention in the field of organic light emitting diodes [38][39][40][41]. While considerable attention has been devoted to the photophysical properties of acridines, not much work has been reported related to

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• Giovanni S. Baviera Paulo M. Donate Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-091, Ribeirão Preto, SP, Brazil 10.3762/bjoc.17.131 Abstract Anthracene and anthracene derivatives have been extensively studied over the

• materials. Their synthesis remains challenging, but some important preparative methods have been reported, especially in the last decade. This review presents an update of the recent strategies that have been employed to prepare anthracene derivatives. It encompasses papers published over the last twelve

• years (2008–2020) and focuses on direct and indirect methods to construct anthracene and anthraquinone frameworks. Keywords: anthracenes; anthraquinones; Friedel–Crafts cyclization; intramolecular cyclization; metal-catalyzed; Introduction Anthracene is an important aromatic hydrocarbon consisting of

2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

• Najeh Tka,
• Mohamed Adnene Hadj Ayed,
• Mourad Ben Braiek,
• Mahjoub Jabli,
• Noureddine Chaaben,
• Kamel Alimi,
• Stefan Jopp and
• Peter Langer

Beilstein J. Org. Chem. 2021, 17, 1629–1640, doi:10.3762/bjoc.17.115

• appeared as a side product during the synthesis of anthracene [11] and became an abundant scaffold in medicinal chemistry [12][13][14]. Acridine derivatives have exhibited a range of biological activities [15][16][17][18][19][20] and have been particularly explored in chemotherapeutic protocols against

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

• medicinally significant molecules. The review has been classified on the basis of the pharmacophores constructed by adopting the MWA-MCRs strategy. Review 1 Acridine Acridine is a polycyclic heteroarene with structural basis as anthracene in which one of the central carbon atoms is replaced by a nitrogen atom

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

Using multiple self-sorting for switching functions in discrete multicomponent systems

• Amit Ghosh and
• Michael Schmittel

Beilstein J. Org. Chem. 2020, 16, 2831–2853, doi:10.3762/bjoc.16.233

• addition of zinc(II), the silver(I) ions were translocated as a second messenger from the nanoswitch [Ag(35)]+ to the anthracene-appended crown ether 36 in a 2-fold completive self-sorting, i.e., furnishing [Zn(35)]2+ and [Ag(36)]+ (state SelfSORT-II). In this state, SelfSORT-II, the emission emerged at

Selective recognition of ATP by multivalent nano-assemblies of bisimidazolium amphiphiles through “turn-on” fluorescence response

• Rakesh Biswas,
• Surya Ghosh,
• Shubhra Kanti Bhaumik and
• Supratim Banerjee

Beilstein J. Org. Chem. 2020, 16, 2728–2738, doi:10.3762/bjoc.16.223

• multiple imidazolium groups to overcome the high hydration enthalpy of phosphates and b) the imidazolium groups are connected to aromatic moieties such as anthracene, pyrene, etc. The variation in the luminescence of the aromatic moieties signals the binding event and furthermore, they provide additional

• of anthracene tagged imidazolium receptors responded to ATP through an amplified fluorescence quenching [60]. Based on these results, we wanted to develop similar self-assembled systems which would show a “turn-on” response in the presence of ATP or other phosphate analytes. The current design of

Nocarimidazoles C and D, antimicrobial alkanoylimidazoles from a coral-derived actinomycete Kocuria sp.: application of ¹J_C,H coupling constants for the unequivocal determination of substituted imidazoles and stereochemical diversity of anteisoalkyl chains in microbial metabolites

• Md. Rokon Ul Karim,
• Enjuro Harunari,
• Amit Raj Sharma,
• Naoya Oku,
• Kazuaki Akasaka,
• Daisuke Urabe,
• Mada Triandala Sibero and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 2719–2727, doi:10.3762/bjoc.16.222

• those of synthetically prepared model imidazoles. The absolute configurations of the anteisoalkanoyl group present in 1, 4, and 5 were determined by low-temperature HPLC analysis of the degradation products labeled with a chiral anthracene reagent, which revealed that 1 is a mixture of the R- and S

• anthracene reagent to yield the esters of (R)- or (S)-2-(anthracene-2,3-dicarboximido)propanol (nat-10-(R)-2A1P, (S)-10-(R)-2A1P, and (S)-10-(S)-2A1P), which were subjected to HPLC analysis for comparison (Figure 4). The retention times of the standard samples were 177 min for (S)-10-(S)-2A1P

Synthesis of 6,13-difluoropentacene

• Matthias W. Tripp and
• Ulrich Koert

Beilstein J. Org. Chem. 2020, 16, 2136–2140, doi:10.3762/bjoc.16.181

• acid precursor could be prepared by reaction of the anthracenyllithium 7 with phthalic anhydride (8). Intermediate 7 could be accessed by ortho-lithiation of anthracene 9. The synthesis of 9 by two consecutive Friedel–Crafts acylation reactions and reduction of the resulting anthraquinone could start

• –Crafts acylation is then performed in polyphosphoric acid at 140 °C, giving anthraquinone 11 in 53% yield over two steps. Reduction of 11 to the anthracene 9 proceeded smoothly using zinc powder in 1,4-dioxane and aqueous ammonia under copper catalysis [15]. To achieve good yields, it was crucial to

Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes

• Thomas Schneider,
• Michael Keim,
• Bianca Seitz and
• Gerhard Maas

Beilstein J. Org. Chem. 2020, 16, 2064–2072, doi:10.3762/bjoc.16.173

• even anthracene. At higher temperature, the cycloadducts undergo an intramolecular SE(Ar) reaction leading to condensed carbocycles incorporating a 1-(trifluoromethyl)-1-(dimethylamine)indene ring system. With styrenes and some substituted styrenes, cascade reactions take place, which likely include

• -substituted propyn-1-iminium salts is also exemplified by the Diels–Alder reaction of 1a with anthracene (Scheme 3). After 12 h at room temperature, a 91% conversion was observed, and subsequent moderate heating gave the cycloaddition product 10 in 95% yield. The subsequent iminium-induced electrophilic

• cyclization required extended heating in refluxing toluene and finally furnished the neutral polycycle 11 in good yield. The paddlewheel-shaped structure of 11 was established by an XRD structure determination and is shown in Figure 1. The reactivity of 1a in the Diels–Alder reaction with anthracene may be

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• yield. The drop in the yield was insignificant in the absence of oxygen. An insignificant drop in the yield was also noticed when an electron scavenger, CuCl2, was added to the reaction mixture, excluding a single electron transfer process. When a triplet state quencher, anthracene, was added, the

Towards triptycene functionalization and triptycene-linked porphyrin arrays

• Gemma M. Locke,
• Keith J. Flanagan and
• Mathias O. Senge

Beilstein J. Org. Chem. 2020, 16, 763–777, doi:10.3762/bjoc.16.70

• Information File 1 for full experimental data). Instead we focused on the synthesis of systems with ethynyl spacers between the triptycene bridgehead positions and chromophores. To allow for the generation of symmetric and unsymmetric dyads 9,10-diethynyltriptycene 5 and its anthracene precursor were

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• -free ATRP strategy [132][133][134][135][136][137]. Latter reference provided a comprehensive overview demonstrating the function of phenothiazine derivatives, perylene, diaryl dihydrophenazines, anthracene or pyrene. In addition, type II photoinitiators including benzophenone, and thioxanthones were

Preparation of anthracene-based tetraperimidine hexafluorophosphate and selective recognition of chromium(III) ions

• Qing-Xiang Liu,
• Feng Yang,
• Zhi-Xiang Zhao,
• Shao-Cong Yu and
• Yue Ding

Beilstein J. Org. Chem. 2019, 15, 2847–2855, doi:10.3762/bjoc.15.278

• 10.3762/bjoc.15.278 Abstract A novel anthracene-based tetraperimidine hexafluorophosphate 3 was prepared, and its structure was determined through X-ray analysis, HRMS as well as 1H and 13C NMR spectroscopy. In the cationic moiety of 3, two (N-ethylperimidinyl–C2H4)2NCH2– arms were attached to the 9- and

• 10-positions of anthracene. In addition, compound 3 was used as a chemosensor to research the ability to recognize Cr3+ through fluorescence and UV titrations, HRMS, as well as 1H NMR and IR spectroscopy. The results indicate that 3 is an effective chemosensor for Cr3+. Keywords: chemosensor

• effective fluorescence turn-on chemosensors for Cr3+ is necessary. In the process of our research, a tetradentate compound bearing a fluorophore aroused our interest. In this paper, we report the synthesis of a novel anthracene-based tetraperimidine hexafluorophosphate 3, and its structure was determined by

Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series

• Sarah L. Skraba-Joiner,
• Carter J. Holt and
• Richard P. Johnson

Beilstein J. Org. Chem. 2019, 15, 2655–2663, doi:10.3762/bjoc.15.258

• 1941 in the rearrangement of benz[a]anthracene to chrysene [27]. We recently studied the rearrangement of anthracene (10) to phenanthrene (11) [28], finding evidence to support a complex process, suggested earlier [29], that involves initial reduction to 1,2,3,4-tetrahydroanthracene, followed by a

• observed earlier by NMR spectroscopy that anthracene is fully protonated at ambient temperature in 1M TfOH but 1,3,5-triphenylbenzene is not [28]. One experimental observation is that the 1M TfOH/arene reaction solutions invariably have a bright color at ambient temperature due to the carbocation [40][41

A new approach to silicon rhodamines by Suzuki–Miyaura coupling – scope and limitations

• Thines Kanagasundaram,
• Antje Timmermann,
• Carsten S. Kramer and
• Klaus Kopka

Beilstein J. Org. Chem. 2019, 15, 2569–2576, doi:10.3762/bjoc.15.250

• the Suzuki–Miyaura cross-coupling reaction gave access to silicon rhodamines with neutral (hetero)aromatic xanthene substituents (phenyl: 67%, respectively 73% brsm; thienyl: 91%) (even though the term ‘dihydrosilaanthracene’ is correct to name the Si-anthracene moiety, the term ‘Si-xanthene’ is

Self-assembled coordination thioether silver(I) macrocyclic complexes for homogeneous catalysis

• Zhen Cao,
• Aline Lacoudre,
• Cybille Rossy and
• Brigitte Bibal

Beilstein J. Org. Chem. 2019, 15, 2465–2472, doi:10.3762/bjoc.15.239

• Zhen Cao Aline Lacoudre Cybille Rossy Brigitte Bibal Université de Bordeaux, Institut des Sciences Moléculaires, UMR CNRS 5255, 351 cours de la libération, 33405 Talence, France 10.3762/bjoc.15.239 Abstract The bis-ortho-thioether 9,10-bis[(o-methylthio)phenyl]anthracene was synthesized as a syn

• the 9,10-aryl substituents in respect to the anthracene core, without any indication of a syn-to-anti isomerization. Four silver(I) complexes 1a–d were prepared in excellent yield (77–92%) by mixing the ligand and the following silver salts in a 1:1 ratio in dichloromethane at room temperature: AgOTf

• distance between two anthracenes was ca. 6.31 Å and the dihedral angle between the anthracene core and its 9,10-aryl substituents was 89° and 104°, respectively. The head-to-tail macrocycle 1a adopted a V-shape (Figure 1b): the angle between the planes of the two anthracenes was 73.2° and the dihedral

Aggregation-induced emission effect on turn-off fluorescent switching of a photochromic diarylethene

• Luna Kono,
• Yuma Nakagawa,
• Ayako Fujimoto,
• Ryo Nishimura,
• Yohei Hattori,
• Toshiki Mutai,
• Nobuhiro Yasuda,
• Kenichi Koizumi,
• Satoshi Yokojima,
• Shinichiro Nakamura and
• Kingo Uchida

Beilstein J. Org. Chem. 2019, 15, 2204–2212, doi:10.3762/bjoc.15.217

• (phenylethynyl)anthracene in hexane (Φf = 1.0) [31]. The luminescence quantum yields of crystalline solids were measured using a JASCO ILF-533 integral sphere attached to a JASCO FP-6600 spectrofluorophotometer. The mixture of microcrystalline compounds (2 mg) and powdered sodium chloride (1 g) were put into a 5