Direct access to pyrido/pyrrolo[2,1-b]quinazolin-9(1H)-ones through silver-mediated intramolecular alkyne hydroamination reactions

• Hengshuai Wang,
• Shengchao Jiao,
• Kerong Chen,
• Xu Zhang,
• Linxiang Zhao,
• Dan Liu,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 416–424, doi:10.3762/bjoc.11.47

• the skeleton of the substrate was replaced by a naphthalene ring, the product was obtained at a comparable yield of 87% (Table 2, entry 11). However, with 2-(4-pentynyl)-thieno[2,3-d]pyrimidin-4(1H)-one (6L) as a substrate, the reaction was significantly different compared to the other substituted 2

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• reported that 4-amino-2-sulfanylphenol derivatives display highly specific protein kinase and angiogenesis inhibitory activities. Based on their previous findings, the structure of compound 24 was optimized by replacing the naphthalene by a phenolic skeleton and a sulfonamide fragment [52]. These compounds

Conjugates of methylated cyclodextrin derivatives and hydroxyethyl starch (HES): Synthesis, cytotoxicity and inclusion of anaesthetic actives

• Lisa Markenstein,
• Antje Appelt-Menzel,
• Marco Metzger and
• Gerhard Wenz

Beilstein J. Org. Chem. 2014, 10, 3087–3096, doi:10.3762/bjoc.10.325

• forms inclusion compounds with derivatives of benzene, naphthalene, adamantane, and many other moieties of similar sizes [3]. Applications of β-CD as complexing agents are limited because of low aqueous solubilities of β-CD and its complexes. Furthermore, the toxic potential of β-CD is known for a long

A small azide-modified thiazole-based reporter molecule for fluorescence and mass spectrometric detection

• Stefanie Wolfram,
• Hendryk Würfel,
• Stefanie H. Habenicht,
• Christine Lembke,
• Phillipp Richter,
• Eckhard Birckner,
• Rainer Beckert and
• Georg Pohnert

Beilstein J. Org. Chem. 2014, 10, 2470–2479, doi:10.3762/bjoc.10.258

• . For comparison, we also synthesized and tested a bromine modified dansyl derivative N-(3-azidopropyl)-6-bromo-5-(dimethylamino)naphthalene-1-sulfonamide (BNS, 6, Figure 2). Dansyl chloride is brominated according to the literature [30] to produce 6-bromo-5-(dimethylamino)naphthalene-1-sulfonyl

• yield and compared it with other commercially available fluorophores of similar size (Figure 2). We chose N-(3-azidopropyl)-5-(dimethylamino)naphthalene-1-sulfonamide (DNS, 8) with a fluorophore system exhibiting a large stokes shift [1] suitable for fluorescence detection with UV filters

Oxidative phenylamination of 5-substituted 1-hydroxynaphthalenes to N-phenyl-1,4-naphthoquinone monoimines by air and light “on water”

• Julio Benites,
• Juan Meléndez,
• Cynthia Estela,
• David Ríos,
• Luis Espinoza,
• Iván Brito and
• Jaime A. Valderrama

Beilstein J. Org. Chem. 2014, 10, 2448–2452, doi:10.3762/bjoc.10.255

• )naphthalene-1(4H)-one (6, 98% yield). Under similar conditions, but using green LEDs light radiation, compound 6 was isolated in 80% yield. The structure of 6 was established by means of 1D and 2D NMR and by X-ray crystallographic studies (Figure 2 and Table S1 in Supporting Information File 1). This

Synthesis of novel conjugates of a saccharide, amino acids, nucleobase and the evaluation of their cell compatibility

• Dan Yuan,
• Xuewen Du,
• Junfeng Shi,
• Ning Zhou,
• Abdulgader Ahmed Baoum and
• Bing Xu

Beilstein J. Org. Chem. 2014, 10, 2406–2413, doi:10.3762/bjoc.10.250

• (NSA) [19] are able to self-assemble to form supramolecular hydrogels and exhibit promising biological functions, such as promoting the development of zygotes [20]. Moreover, both NAS- and NSA-type conjugates exhibit excellent cell compatibility. Except for a few known motifs (naphthalene [21][22

• form a viscous aqueous solution at a concentration of 3 wt % (pH 4.0) after one week aging. Although our previous study shows that the incorporation of naphthAla, a naphthalene-containing unnatural amino acid, into NSA is able to induce hydrogelation [19], the introduction of naphthAla to 1 or 2, which

Influence of perylenediimide–pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity

• Christian B. Winiger,
• Simon M. Langenegger,
• Oleg Khorev and
• Robert Häner

Beilstein J. Org. Chem. 2014, 10, 1589–1595, doi:10.3762/bjoc.10.164

• aedamers (aromatic electron donor acceptor oligomers) pioneered by Iverson and coworkers [18][36][37]. They consist of face-to-face stacked electron-rich naphthalene and electron-poor naphthalenediimide (NDI) chromophores and belong to the broader area of foldamers [38]. DNA has been described as a

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• case the steric demand of the naphthalene spacing units does not allow for the optimal positioning of the C60 and the formation of a 4c@C60 complex of measurable stability. Conclusion We have reported on the synthesis and characterization of novel homochiral macrocycles, built upon resolved 1,1

• , 1.34 mmol, 2 equiv). Purified by flash column chromatography (hexanes/EtOAc 7:3) to yield 3c (30 mg, 8%) and 4b (17 mg, 5%) as white solids. (R,R)-3c. [α]D25 +97 (c 0.0015, CH2Cl2); ESIMS m/z (%): 1131 ([M + Na]+, 100); 1H NMR (CDCl3, 200 MHz, 25 °C) δ 8.80 (m, 4H, naphthalene), 8.22 (s, 4H

• , naphthalene), 8.02 (s, 4H, binaphthyl), 7.94 (d, 4H, binaphthyl), 7.53 (m, 4H, naphthalene), 7.43 (t, 4H, binaphthyl), 7.27 (m, 4H, binaphthyl), 7.16 (d, 4H, binaphthyl), 5.72 (q, 8H, CH2), 3.34 (s, 12H, OCH3); 13C NMR (CDCl3, 75 MHz, 25 °C) δ 167.0 (Cq), 155.8 (Cq), 134.8 (Cq), 133.1 (CH), 131.9 (Cq), 131.2

Site-selective covalent functionalization at interior carbon atoms and on the rim of circumtrindene, a C₃₆H₁₂ open geodesic polyarene

• Hee Yeon Cho,
• Ronald B. M. Ansems and
• Lawrence T. Scott

Beilstein J. Org. Chem. 2014, 10, 956–968, doi:10.3762/bjoc.10.94

• ., a bromine atom (Figure 9). Since the α-positions of the naphthalene subunits should be more reactive than the crowded β-positions, the site selectivity between the two types of rim carbon atoms was not expected to present a problem. We were aware, however, that the interior carbon atoms of

• conclude that the higher field resonance (1.12 ppm) corresponds to the methyl group over the concave side, whereas the lower field resonance (2.29 ppm) corresponds to the methyl group over the convex side. Since the walls of circumtrindene consist of three naphthalene units, a 2,6-dimethylphenyl

• substituted naphthalene 31 was synthesized as a reference compound [61]. The naphthalene units of circumtrindene are arched, but the naphthyl group of 31 is planar; therefore, it provides a good comparison for shielding and de-shielding effects. The 1H NMR spectrum of reference compound 31 shows that the

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

• can be explained based on steric and electronic factors. In the case derived from 3-chloro-4-fluoroaniline, the C–C bond formation occurred at position 6 of the aromatic ring as it was sterically favoured. In case of the 2-naphthylamine derivative, position 1 of the naphthalene ring is known to be

Unusual polymorphism in new bent-shaped liquid crystals based on biphenyl as a central molecular core

• Anna Kovářová,
• Svatopluk Světlík,
• Václav Kozmík,
• Jiří Svoboda,
• Vladimíra Novotná,
• Damian Pociecha,
• Ewa Gorecka and
• Natalia Podoliak

Beilstein J. Org. Chem. 2014, 10, 794–807, doi:10.3762/bjoc.10.75

• -shaped LC materials is most commonly based on a 1,3-disubstitued benzene and a 2,7-disubstitued naphthalene central unit to which flexible lengthening arms are joined to create mesogens with symmetrical or non-symmetrical molecular architecture. Furthermore, already in the beginning of the extensive

Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers

• Dae Won Cho,
• Patrick S. Mariano and
• Ung Chan Yoon

Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47

• consequence, it would be accompanied concomitantly by a dislocation of the side chain moiety and a reduction in intramolecular SET quenching of the singlet excited naphthalene fluorophore by the strong electron donating sulfur and nitrogen atoms. In the studies, it was observed that fluorescence of these and

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• corresponding tricyclic naphthalene fused pyrazoles 15 (Scheme 12, path A). Moreover, in a subsequent work, the authors applied the same strategy to obtain pyrazolo[4,3-b]indoles 16, a new class of CK2 inhibitors [42]. These products were obtained starting from properly substituted dihydropyrazoles 13 in which

Continuous flow nitration in miniaturized devices

• Amol A. Kulkarni

Beilstein J. Org. Chem. 2014, 10, 405–424, doi:10.3762/bjoc.10.38

• and industrial explosive. Nitro derivatives of glycerine, urea and naphthalene also exhibit explosive properties. Some of the aniline based dyes were used for medical applications, too. The extension of the aniline based medicines led to hundreds of drugs [11], which were used for medication during

• nitration of thioureas is based on subsequent nitrosation and nitration steps. The same group also analyzed continuous processes to perform the strongly exothermic nitration of naphthalene (47) (Scheme 14) with N2O5, both in the gas phase and in the liquid phase [49][50]. The authors reported that the

Total synthesis and cytotoxicity of the marine natural product malevamide D and a photoreactive analog

• Werner Telle,
• Gerhard Kelter,
• Heinz-Herbert Fiebig,
• Peter G. Jones and
• Thomas Lindel

Beilstein J. Org. Chem. 2014, 10, 316–322, doi:10.3762/bjoc.10.29

• equiv), pyridine·SO3 (5 equiv), 0 °C, 1 h, 91%. b) LDA (2.5 equiv), t-BuOAc (1.3 equiv), THF, −78 °C, 1 h; separation of diastereomers, (3R,4S)-6: 47%. c) 1,8-bis(dimethylamino)naphthalene (2.5 equiv), Me3OBF4 (2.6 equiv), 4 Å MS, 1,2-DCE, 0 °C, 2 h, rt, 16 h, 87%. d) H2, Pd/C (5%), MeOH, rt, 1 h. e) 8

Synthesis of five- and six-membered cyclic organic peroxides: Key transformations into peroxide ring-retaining products

• Alexander O. Terent'ev,
• Dmitry A. Borisov,
• Vera A. Vil’ and
• Valery M. Dembitsky

Beilstein J. Org. Chem. 2014, 10, 34–114, doi:10.3762/bjoc.10.6

• '-indene] (75a) and 5-hydroperoxy-3',4'-dihydro-2'H-spiro[[1,2]dioxolane-3,1'-naphthalene] (75b), were synthesized by the ozonolysis of 1-allyl-1-hydroperoxy-2,3-dihydro-1H-indene (72a) and 1-allyl-1-hydroperoxy-1,2,3,4-tetrahydronaphthalene (72b), respectively, in an Et2O/CF3CH2OH system (2:1). The

Recent advances in transition metal-catalyzed Csp²-monofluoro-, difluoro-, perfluoromethylation and trifluoromethylthiolation

• Grégory Landelle,
• Armen Panossian,
• Sergiy Pazenok,
• Jean-Pierre Vors and
• Frédéric R. Leroux

Beilstein J. Org. Chem. 2013, 9, 2476–2536, doi:10.3762/bjoc.9.287

• excess) were heated under air in the absence of a cosolvent (Table 8). Benzene, naphthalene and several disubstituted benzenes were successfully transformed with 39–99% NMR yields and 27–76% isolated yields (relative to the starting perfluoroalkyl iodide). N-Methylpyrrole was also perfluoroalkylated in

Crystal design using multipolar electrostatic interactions: A concept study for organic electronics

• Peer Kirsch,
• Qiong Tong and
• Harald Untenecker

Beilstein J. Org. Chem. 2013, 9, 2367–2373, doi:10.3762/bjoc.9.272

• "walls". This difference between hole and electron transfer can be explained by the geometries of the HOMO and LUMO orbitals (Figure 6) and their different modes of overlap in the arrangements A–D. Whereas the HOMO is all over the aromatic part of 1, the LUMO is more contracted to the central naphthalene

Gold-catalyzed reaction of oxabicyclic alkenes with electron-deficient terminal alkynes to produce acrylate derivatives

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 1969–1976, doi:10.3762/bjoc.9.233

• ). Since naphthalene-1-ol (5) was obtained in this reaction, we used naphthalene-1-ol (5) as a substrate and carried out the reaction under the optimal conditions to clarify whether the reaction proceeded through naphthalene-1-ol. The formation of 3a could not be observed, suggesting that naphthalene-1-ol

• formed by a regioselective opening of the oxygen bridge in substrate 1a. Intermediate A releases a proton to afford intermediate B. Intermediate B attacks methyl propiolate, which is activated by the gold catalyst, to generate gold vinyl complex C. In intermediate C, the ester group and the naphthalene

• , intermediate B attacks non-coordinated alkyne ketone 2i in a cis-addition manner to generate gold vinyl complex D. In intermediate D, the carbonyl group and the naphthalene ring are on opposite sides, affording product 3i with (E)-configuration by protodeauration. Conclusion In summary, we have developed a

Topochemical control of the photodimerization of aromatic compounds by γ-cyclodextrin thioethers in aqueous solution

• Hai Ming Wang and
• Gerhard Wenz

Beilstein J. Org. Chem. 2013, 9, 1858–1866, doi:10.3762/bjoc.9.217

• complexes with polycyclic aromatics, such as naphthalene, anthracene (ANT), and acenaphthylene (ACE) [25]. In the following we report on the photochemistry of ANT, ACE and coumarin (COU), templated by complexation in several hydrophilic γ-CD thioethers 1–7 (Figure 1 and Figure 2). Special attention will be

Synthesis and biological activities of the respiratory chain inhibitor aurachin D and new ring versus chain analogues

• Xu-Wen Li,
• Jennifer Herrmann,
• Yi Zang,
• Philippe Grellier,
• Soizic Prado,
• Rolf Müller and
• Bastien Nay

Beilstein J. Org. Chem. 2013, 9, 1551–1558, doi:10.3762/bjoc.9.176

• naphthalene analogue, yet without totally explaining the observed cytotoxic activity of the compounds. Finally, a synthetic entry is given to the complete carboheterocyclic core of aurachin H through the N-oxidation/epoxidation of aurachin D and a shorter chain analogue, followed by subsequent biomimetic

Synthesis and spectroscopic properties of 4-amino-1,8-naphthalimide derivatives involving the carboxylic group: a new molecular probe for ZnO nanoparticles with unusual fluorescence features

• Laura Bekere,
• David Gachet,
• Vladimir Lokshin,
• Wladimir Marine and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2013, 9, 1311–1318, doi:10.3762/bjoc.9.147

• . Photophysical properties The spectroscopic properties of 1,8-naphthalimides are strongly dependent on the substituent at C-4 of the naphthalene ring. In general, the derivatives with a halogen atom or alkoxy groups are colorless and exhibit blue fluorecence [15][16], while the amino-substituted 1,8

• orbitals localized within the naphthalene and phenyl rings. These results are in a good agreement with the experiment (Figure 1). It is noteworthy that both HOMO and LUMO orbitals are delocalized and involve both the naphthalene moiety and the amino substituent (Figure 6a,b). In addition, the phenyl ring

Amyloid-β probes: Review of structure–activity and brain-kinetics relationships

• Todd J. Eckroat,
• Abdelrahman S. Mayhoub and
• Sylvie Garneau-Tsodikova

Beilstein J. Org. Chem. 2013, 9, 1012–1044, doi:10.3762/bjoc.9.116

• (9) and diphenyl-1,3,4-oxadiazole (10); and thioflavin-T analogues such as benzothiazole (11), benzoxazole (12), benzofuran (13), imidazopyridine (14), and benzimidazole (15); as well as quinoline (16) and naphthalene (17) derivatives (Figure 1B). In this review, we provide an overview of these AD

• naphthalene analogues Quinolines Investigation of the quinoline scaffold for imaging in AD has yielded some interesting results, despite there only being a few examples in the literature. The [18F]-labeled 2-fluoroquinolin-8-ol [18F]CABS13 (149) has recently been reported (Figure 5) [98]. The straightforward

• , and, with favorable pharmacokinetics, it was able to highlight tau pathology in vivo in transgenic mice [100]. Naphthalenes Replacement of the cyclic nitrogen in the quinoline scaffold described in the previous section affords the naphthalene scaffold. This scaffold has shown promising results for Aβ

Spectroscopic characterization of photoaccumulated radical anions: a litmus test to evaluate the efficiency of photoinduced electron transfer (PET) processes

• Maurizio Fagnoni,
• Stefano Protti,
• Davide Ravelli and
• Angelo Albini

Beilstein J. Org. Chem. 2013, 9, 800–808, doi:10.3762/bjoc.9.91

• solution) in the presence of tertiary amines allowed the accumulation of the corresponding radical anions, up to quantitative yield for polysubstituted benzenes and partially with naphthalene and anthracene derivatives. The condition for such an accumulation was that the donor radical cation underwent

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39