Fluorinated azobenzenes as supramolecular halogen-bonding building blocks

• Esther Nieland,
• Oliver Weingart and
• Bernd M. Schmidt

Beilstein J. Org. Chem. 2019, 15, 2013–2019, doi:10.3762/bjoc.15.197

• ) and E-4,4’-di(iodoethynyl)perfluoroazobenzene (A3) halogen bond donors can be combined with rigid u-shaped anthracene building blocks, bearing two 3,5-lutidine acceptors in 1 and 8 positions, to form self-assembled boxes of 25–30 Å length in solution and in the solid state [35]. We chose azobenzene

• . Single-crystal analysis confirms the formation of a U1···A2 box in the solid state (Figure 3). The U1···A2 box has a principal length of approximately 25 Å (anthracene–anthrance distance) and a height of 5 Å (distance between the ipso-carbons of the lutidines). The lutidine acceptor units are curved

• inwards (with N···I–C angles of 165 and 172°) and show N···I distances of 2.78 and 2.82 Å to the azobenzene donors. As observed for the other boxes assembled by halogen bonding reported by us [35], parts containing fluorinated azobenzenes A2 are segregated from the perhydrogenated anthracene U1 units

Synthesis of a [6]rotaxane with singly threaded γ-cyclodextrins as a single stereoisomer

• Jason Yin Hei Man and
• Ho Yu Au-Yeung

Beilstein J. Org. Chem. 2019, 15, 1829–1837, doi:10.3762/bjoc.15.177

• azide–alkyne cycloaddtion (CBAAC) with the anthracene-derived propagylamine stopper 2. In CBAAC, the strong ammonium–CB[6] binding places the alkyne and azide in a close proximity inside the CB[6] cavity and facilitates the cycloaddition [40][41][42]. Since CB[6] binding is required for the covalent

• bond formation, interlocking of the macrocycle is ensured to result in a good efficiency of mechanical bond formation. The synthesis of 1 and 2 is depicted in Scheme 1. To synthesize hetero[n]rotaxanes containing both γ-CD and CB[6], a 1:1 mixture of the anthracene stopper 2 and CB[6] in 50 mM HCl was

• Information File 1). In the MS/MS spectra, fragments corresponding to the loss of the γ-CD and the anthracene stoppers were observed, suggesting the breaking of the glycosidic bonds of the γ-CD and the anthracene–CH2(NRH2)+ bond as the major fragmentation pathways (Figures S24–S27 in Supporting Information

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

Synthesis, enantioseparation and photophysical properties of planar-chiral pillar[5]arene derivatives bearing fluorophore fragments

• Guojuan Li,
• Chunying Fan,
• Guo Cheng,
• Wanhua Wu and
• Cheng Yang

Beilstein J. Org. Chem. 2019, 15, 1601–1611, doi:10.3762/bjoc.15.164

• quantum yield was only slightly decreased. This should be mainly due to the steric hindrance of the 9- and 10-phenyl groups, which inhibited the π–π stacking of the anthracene core in DPA. The fluorescent lifetimes of P5A-Py and P5A-DPA were compared with Py-6 and DPA-6. As shown in Figure 2, the lifetime

• baseline, indicating particles of larger size were formed. The CD signals continuously increased accompanied with a red-shifting of the wavelength, thus demonstrating that the DPA pigments started to aggregate in solutions with a water content of more than 50%. The π–π stacking of the anthracene core in

2,3-Dibutoxynaphthalene-based tetralactam macrocycles for recognizing precious metal chloride complexes

• Li-Li Wang,
• Yi-Kuan Tu,
• Huan Yao and
• Wei Jiang

Beilstein J. Org. Chem. 2019, 15, 1460–1467, doi:10.3762/bjoc.15.146

• abovementioned precious metal chloride complexes. This is in contrast to the fact that the tetralactam macrocycle with anthracene as the sidewalls only show good binding affinities to AuCl4−. The superior binding to all three complexes may be due to the conformational diversity of the naphthalene-based

• recognition of glucose in water [21][22][23]. However, the aromatic sidewalls of these tetralactams are currently limited to benzene, anthracene and their derivatives (Scheme 1). The extension of the sidewalls to naphthalenes should be an important supplement to the previous works, and may even lead to

• tetralactam macrocycle with anthracene sidewalls [34]. The difference in binding affinities and selectivity may be partially due to the conformational diversity in the tetralactam macrocycles with 2,3-dibutoxynaphthalene as the sidewalls. Moreover, they are fluorescent and could in principle be used as a

Selective detection of DABCO using a supramolecular interconversion as fluorescence reporter

• Indrajit Paul,
• Debabrata Samanta,
• Sudhakar Gaikwad and
• Michael Schmittel

Beilstein J. Org. Chem. 2019, 15, 1371–1378, doi:10.3762/bjoc.15.137

• fluorescence at λ = 602 nm. Ligands, such as pyrazine, 2-chloropyrazine, 1,4-dimethylpiperazine, anthracene, pyrene, coronene, perylene, and perylene-3,4,9,10-tetracarboxylic dianhydride were compared to DABCO. Only in presence of DABCO the fluorescence maximum was shifted to λ = 618 nm along with the color

Mechanochemical Friedel–Crafts acylations

• Mateja Đud,
• Anamarija Briš,
• Iva Jušinski,
• Davor Gracin and
• Davor Margetić

Beilstein J. Org. Chem. 2019, 15, 1313–1320, doi:10.3762/bjoc.15.130

• , in which acylation was accompanied with the cleavage of the methoxy group [43][44][45]. A striking advantage of the automated ball milling over manual grinding [46] is evident in the reaction of anthracene with phthalic anhydride which gave no product by manual grinding and the yield of the toluene

• reaction is increased from 68% to 92%. When anthracene was subjected to a milling reaction with succinic anhydride, 9-substituted product 22 was obtained in low yield, and accompanied with a small amount of 2-acylated product 23 (Scheme 4), with same regioselectivity to that reported in the literature [47

• ][48]. FC acylation at the 2-position of anthracene was achieved by Levy by the employment of 9,10-dihydroanthracene and subsequent oxidation to anthracene. To direct the acylation towards the 2-position, we devised the use of anthracene photodimer 19 [49] for the protection of 9,10-positions. The

Enantioselective Diels–Alder reaction of anthracene by chiral tritylium catalysis

• Qichao Zhang,
• Jian Lv and
• Sanzhong Luo

Beilstein J. Org. Chem. 2019, 15, 1304–1312, doi:10.3762/bjoc.15.129

• of a highly active carbocation Lewis acid catalyst. The stereocontrol potential of the chiral tritylium ion pair was demonstrated by its application in an enantioselective Diels–Alder reaction of anthracene. Keywords: anthracene; carbocation catalysis; Diels–Alder reaction; Fe(III)-based phosphate

• ; see Supporting Information File 1 for details). We next tested the metal phosphate strategy in the Diels–Alder reaction of anthracene, for which a catalytic asymmetric version has not been achieved yet. Recently, we reported that the tritylium salt [Ph3C][BArF], in situ generated by Ph3CBr and NaBArF

• anthracene (3a) and β,γ-unsaturated α-ketoester 4a. When TP was first treated with metal Lewis acid (Scheme 2a, and Table S1 in Supporting Information File 1), the reaction showed good reactivity but no enantioselectivity at all, indicating a strong background reaction (Table 1, entry 2). We next examined

Molecular recognition using tetralactam macrocycles with parallel aromatic sidewalls

• Dong-Hao Li and
• Bradley D. Smith

Beilstein J. Org. Chem. 2019, 15, 1086–1095, doi:10.3762/bjoc.15.105

• -conformational motion such as macrocycle pirouetting around the encapsulated guest [50][51]. The Smith group has found that an organic soluble version of anthracene-containing tetralactam B is able to encapsulate squaraine, thiosquaraine and croconaine dyes [33][57][58][59]. Solid-state structures of various

• crystal structures of acene and azaacene guests inside tetralactam B with the surrounding macrocycle in chair or boat conformations [25]. Recent work has shown that water-soluble versions of anthracene tetralactam B can be threaded by water soluble squaraine dyes with very high affinities (Ka ≈ 109 M−1

• where the guest benzyl group engages in aromatic stacking with the host anthracene sidewalls. Furthermore, the affinities followed a rough linear free energy relationship with electron density on the benzyl group, with highest affinity achieved when the benzylammonium contained a withdrawing p-CN group

Catalysis of linear alkene metathesis by Grubbs-type ruthenium alkylidene complexes containing hemilabile α,α-diphenyl-(monosubstituted-pyridin-2-yl)methanolato ligands

• Tegene T. Tole,
• Johan H. L. Jordaan and
• Hermanus C. M. Vosloo

Beilstein J. Org. Chem. 2019, 15, 194–209, doi:10.3762/bjoc.15.19

• . 1H NMR spectra were recorded at 5–6 minute intervals for 5–8.5 h. For temperature ranges 60–90 °C, 1H NMR of the precatalyst was done alone before adding the 1-octene. The precatalyst (11.5 mg, 0.014 mmol) and anthracene (5.2 mg, 0.03 mmol) were mixed in the metathesis reaction where anthracene was

Adhesion, forces and the stability of interfaces

• Robin Guttmann,
• Johannes Hoja,
• Christoph Lechner,
• Reinhard J. Maurer and
• Alexander F. Sax

Beilstein J. Org. Chem. 2019, 15, 106–129, doi:10.3762/bjoc.15.12

Design and synthesis of C₃-symmetric molecules bearing propellane moieties via cyclotrimerization and a ring-closing metathesis sequence

• Sambasivarao Kotha,
• Saidulu Todeti and
• Vikas R. Aswar

Beilstein J. Org. Chem. 2018, 14, 2537–2544, doi:10.3762/bjoc.14.230

• expanded the scope of this strategy. To this end, commercially available anthracene (16) was reacted with maleic anhydride (7) in a screw-capped tube at 150 °C in o-xylene to obtain the DA adduct 17 in 94% yield [44][45]. Later, the DA adduct 17 was treated with 4-aminoacetophenone (9) in the presence of

Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps

• Sambasivarao Kotha,
• Milind Meshram and
• Chandravathi Chakkapalli

Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223

• -workers [33] demonstrated an efficient route for the construction of the benz[a]anthracene structural unit by employing SM cross coupling followed by RCM sequence. Treatment of the bromonaphthalene derivative 20 with (2-formyl-4-methoxyphenyl)boronic acid (21) in the presence of a palladium catalyst

• organic synthesis and green chemistry. Various catalysts used for metathesis reactions. Various angucyclines. SM coupling and RCM protocol to substituted indene derivative 10. Synthesis of polycycles via SM and RCM approach. SM coupling and RCM protocol to the benz[a]anthracene skeleton 26. Synthesis of

A pyridinium/anilinium [2]catenane that operates as an acid–base driven optical switch

• Sarah J. Vella and
• Stephen J. Loeb

Beilstein J. Org. Chem. 2018, 14, 1908–1916, doi:10.3762/bjoc.14.165

• (pyridinium)ethane and benzylanilinium recognition sites that can be switched by acid–base chemistry and optically sensed by a) a color change from colorless to yellow and b) a change in fluorescence from OFF to ON (CD3CN or CD2Cl2). Code: F to indicate CF3 groups; A to indicate anthracene group. A [3

Steric “attraction”: not by dispersion alone

• Ganna Gryn’ova and
• Clémence Corminboeuf

Beilstein J. Org. Chem. 2018, 14, 1482–1490, doi:10.3762/bjoc.14.125

• hydrocarbons has been emphasized by Sherrill et al. in 2009 [55]. Accordingly, several potentials with accurate electrostatics treatment have been developed and successfully applied to describe the intermolecular interactions of anthracene [56], polycyclic aromatic hydrocarbons [57][58][59][60] and fullerene

A three-armed cryptand with triazine and pyridine units: synthesis, structure and complexation with polycyclic aromatic compounds

• Claudia Lar,
• Adrian Woiczechowski-Pop,
• Attila Bende,
• Ioana Georgeta Grosu,
• Natalia Miklášová,
• Elena Bogdan,
• Niculina Daniela Hădade,
• Anamaria Terec and
• Ion Grosu

Beilstein J. Org. Chem. 2018, 14, 1370–1377, doi:10.3762/bjoc.14.115

• reported cage-box [11] is able to complex a plethora of aromatic compounds (e.g., anthracene, pyrene, perylene), while in the cases of several metallo-based cryptands the formation of layered host–guest supramolecular structures (with many guests in the cavity of the host) were reported [12][13][14][15

• 1 towards aromatic guests (anthracene, pyrene) in solution was observed and the formation of a cryptand–pyrene complex was revealed by cyclic voltammetry only after the adsorption of the cryptand on a graphite surface (electrode). In a more recent paper [33], authors who reobtained our cryptand 1

• pyrene, anthracene and 1,5-dihydroxynaphthalene as guest molecules was investigated by NMR titration experiments and molecular modelling. The spectra recorded during the NMR titrations of cryptand 2 with increasing amounts of the named guests (ratio 1:9 to 9:1), revealed only one set of signals. However

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

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds

• Baris Temelli and
• Hilal Kalkan

Beilstein J. Org. Chem. 2018, 14, 187–193, doi:10.3762/bjoc.14.13

• ) position of substitution (meso or β). So far, corrole macrocyles have been integrated into porphyrin conjugates via anthracene, biphenylene, xanthene, dibenzofuran [16][17][18][19][20], amide [21] and triazole [22][23] linkers. Despite the large number of studies on the synthesis of porphyrin–corrole

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• substitution by reaction with NaN3 then resulted in AuNPs with mixed monolayers containing 52% N3- and 44% CH3-terminated alkanethiol ligands. A series of alkynes were synthesised, including derivatives of nitrobenzene (1), ferrocene (2), anthracene (3), pyrene (4), aniline (5), and polyethylene glycol (6) all

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF₃SO₂Na

• Hélène Guyon,
• Hélène Chachignon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272

• -unsaturated ketones 58 (Scheme 31b). Benzophenone (BP) or anthracene-9,10-dione (AQ) were used as sensitizers under irradiation using a UV lamp at 280 nm. A radical pathway that involves CF3• was established after a negative reaction in the presence of TEMPO (TEMPO–CF3 was detected by GC–MS). An example of

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• -dienes such a buta-1,3-diene, isoprene, cyclopentadiene and anthracene. In all cases the reaction occurred at elevated temperature and afforded the expected cycloadducts in good to excellent yields [41]. The problem of the configuration of the substituents has not been discussed, but it seems likely that

• thermolabile [4 + 2]-cycloadducts 38 was observed in reactions of some dialkyl dicyanofumarates E-1 with anthracene (39a) and 9,10-dimethylanthracene (39b) [8][43] (Scheme 13). In an experiment with 38b and tert-butyl tricyanoacrylate (40) in CDCl3 at 25 °C an exchange of the dipolarophile leading to 41 was

Mechanochemical synthesis of thioureas, ureas and guanidines

• Vjekoslav Štrukil

Beilstein J. Org. Chem. 2017, 13, 1828–1849, doi:10.3762/bjoc.13.178

• were isolated in quantitative yields. The amination reaction was then performed on a number of substrates, ranging from simple mono- and disubstituted anilines, benzylamines and polyaromatic amines such as anthracene-, phenanthrene-, pyrene- and crysenamine (Scheme 12). An interesting feature of LAG

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• et al. have synthesized 3-methyl-substituted benz[f]indan-1-one 291 in 35% yield from o-bis(dibromomethyl)benzene (286) and 4-methylcyclopent-2-enone (289) (Scheme 81) [113]. 2.4 From other compounds Albrecht, Defoin and Siret have synthesized benz[f]indan-1-one (295) from the anthracene epidioxide

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

• to the π–π* transition for the studied thiophene, phenyl, naphthalene and anthracene-substituted derivatives, shows a small hypsochromic shift with increasing spatial volume of the substituent R. This observation is in a full accordance with the aforementioned relationship of the molecule planarity

• increasing size of the substituent and, as a consequence, dihedral angles between the substituent and the central part of the molecule, the difference in electron-density localization becomes more pronounced. In case of the anthracene substituent an almost complete localization of the HOMO on the central

• core and the LUMO on the anthracene fragment is observed. Conclusion To summarize, we have shown that ethyl esters of 5'-aryl 3-decyl-2,2'-bithiophene-5-carboxylic acids can be prepared by the palladium-catalyzed coupling of readily available compounds, namely ethyl 3-decyl-2,2'-bithiophene-5