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

The chemistry of bisallenes

• Henning Hopf and
• Georgios Markopoulos

Beilstein J. Org. Chem. 2012, 8, 1936–1998, doi:10.3762/bjoc.8.225

Synthesis and structure of tricarbonyl(η⁶-arene)chromium complexes of phenyl and benzyl D-glycopyranosides

• Thomas Ziegler and
• Ulrich Heber

Beilstein J. Org. Chem. 2012, 8, 1059–1070, doi:10.3762/bjoc.8.118

• -exchange reaction between an arene and, most conveniently, either naphthalene–Cr(CO)3 complex or (MeCN)3Cr(CO)3 in which the chromium ligand is only weakly bound [14]; (b) simply heating the arene with hexacarbonylchromium in an inert solvent (Mahaffy–Pauson method) [15][16]. Method (a) has the

• aglycon in order to avoid complexation of hexacarbonylchromium with the basic nitrogen atom. However, all attempts to convert 1l into the corresponding tricarbonyl(η6-pyridine)chromium complex failed. Attempts to prepare a chromium complex of 1l by a ligand exchange reaction with naphthalene–Cr(CO)3 or

Synthesis and in silico screening of a library of β-carboline-containing compounds

• Kay M. Brummond,
• John R. Goodell,
• Matthew G. LaPorte,
• Lirong Wang and
• Xiang-Qun Xie

Beilstein J. Org. Chem. 2012, 8, 1048–1058, doi:10.3762/bjoc.8.117

• these cases, it was assumed that competing coordination of the heteroatom to the silver ion was an issue; however, attempts were not made to alter the reaction conditions for these substrates. Furthermore, conversion of the naphthalene-containing analogues 1{14} and 1{15} to their corresponding

The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

• Renjie Wang,
• Shouzhi Pu,
• Gang Liu and
• Shiqiang Cui

Beilstein J. Org. Chem. 2012, 8, 1018–1026, doi:10.3762/bjoc.8.114

• fluorophores via a Schiff base structure. In a previous work, we developed a new class of diarylethenes with a naphthalene group and a thiophene group. The results revealed that these molecules have excellent photochromism with good fatigue resistance and thermal stability [37]. In this study, in order to

• further elucidate the substituent position effects on the photochromic features of naphthalene-containing diarylethenes, we synthesized three new isomeric diarylethenes with a formyl group at the para, meta, and ortho position on the terminal benzene ring (1–3). The photochromic scheme of 1–3 is shown in

• the fluorescence emission intensity of diarylethenes with a naphthalene moiety. Diarylethenes 1–3 exhibited an evident fluorescence switching capability upon changing from the open-ring to the closed-ring isomers by photoirradiation in both hexane and PMMA films. When irradiated by UV light, the

Fifty years of oxacalix[3]arenes: A review

• Kevin Cottet,
• Paula M. Marcos and
• Peter J. Cragg

Beilstein J. Org. Chem. 2012, 8, 201–226, doi:10.3762/bjoc.8.22

• found to be necessary to remove the ethanol stabilizer and to aid deprotection. Yields were up to 50%, and, interestingly, there was no template effect from any alkali metals. An analogous strategy was developed by Georghiou in 2001 to prepare asymmetric oxacalix[3]naphthalene derivatives [20], and this

• yield of the cone conformer never exceeded 22%. An experiment with the oxacalix[3]naphthalene analogue was performed in 2003 by Georghiou [30], which also gave the cone conformer in 25% yield. Cone-12a was used by Shinkai as the starting point from which to construct the chiral capped oxacalix[3]arene

Valence isomerization of cyclohepta-1,3,5-triene and its heteroelement analogues

• Helen Jansen,
• J. Chris Slootweg and
• Koop Lammertsma

Beilstein J. Org. Chem. 2011, 7, 1713–1721, doi:10.3762/bjoc.7.201

• with solutions highly enriched with either one or the other isomer [38][55]. The facile 3→4 valence isomerization [56][57][58], pioneered by the synthesis of 1,2-naphthalene oxide by Vogel and Klärner [1][59][60], is of considerable interest as arene oxides are intermediates in the oxidative metabolism

Multistep flow synthesis of vinyl azides and their use in the copper-catalyzed Huisgen-type cycloaddition under inductive-heating conditions

• Lukas Kupracz,
• Jan Hartwig,
• Jens Wegner,
• Sascha Ceylan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2011, 7, 1441–1448, doi:10.3762/bjoc.7.168

• means of an IR pyrometer. We chose 2-(1-azidovinyl)naphthalene (4b) and phenylacetylene (11a) as reaction partners for optimization. First, we had to find the best copper source (Table 3). We found that Cu-turnings gave complete conversion and a good isolated yield (Table 3, entry 2) for which the

Meta-metallation of N,N-dimethylaniline: Contrasting direct sodium-mediated zincation with indirect sodiation-dialkylzinc co-complexation

• David R. Armstrong,
• Liam Balloch,
• Eva Hevia,
• Alan R. Kennedy,
• Robert E. Mulvey,
• Charles T. O'Hara and
• Stuart D. Robertson

Beilstein J. Org. Chem. 2011, 7, 1234–1248, doi:10.3762/bjoc.7.144

• usually inert towards orthodox organozinc reagents including benzene [15] and naphthalene [16]. These studies – that have been structurally supported by X-ray crystallography in tandem with NMR spectroscopy – have uncovered the chemical synergy that these mixed-metal alternatives can exhibit, which

One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• planar, cyclic conjugation of 10 π-electrons. The dipole moment of 1a at μ = 1.08 D [20] is astoundingly large in comparison to that of naphthalene at μ = 0 D and can be rationalized by a significant contribution of cyclopentadienyl anion/tropylium cation resonance structures (Scheme 1) [19]. Since the

When gold can do what iodine cannot do: A critical comparison

• Sara Hummel and
• Stefan F. Kirsch

Beilstein J. Org. Chem. 2011, 7, 847–859, doi:10.3762/bjoc.7.97

• , where NIS was used as the electrophilic agent [90]. Alkyne activation yields the iodonaphthalene as the sole product by an analogous 6-endo process. Both methods, regardless of whether the cyclization is triggered by Au+ or I+, require an alkyl substituent at the C2-position for naphthalene formation to

Synthetic applications of gold-catalyzed ring expansions

• David Garayalde and
• Cristina Nevado

Beilstein J. Org. Chem. 2011, 7, 767–780, doi:10.3762/bjoc.7.87

• . After the first examples on the perchlorination of naphthalene with AuCl3 or AuCl by Schwemberger and Gordon in 1935 [10], almost forty years passed without a single report on the catalytic ability of gold salts, due to its presumed lack of reactivity. In 1972, Paul G. Gassman reported several studies

When cyclopropenes meet gold catalysts

• Frédéric Miege,
• Christophe Meyer and
• Janine Cossy

Beilstein J. Org. Chem. 2011, 7, 717–734, doi:10.3762/bjoc.7.82

• to the isomeric substituted naphthalene 21 as the sole product. Shi et al. had previously demonstrated that indene 20 and naphthalene 21 could be selectively formed using Cu(OTf)2 and BF3·OEt2 as catalysts, respectively, thereby highlighting the complementarities of the different electrophilic

• activators [31]. Since AgOTf and BF3·OEt2 led to the same naphthalene product 21, the authors suspected that traces of the Brønsted acid (HOTf) present in the silver salt may be the actual catalyst and may also modify the regioselectivity observed in the gold-catalyzed reaction. Thus, several basic additives

• with traces of water) should favour the formation of the more stable cyclopropyl cation 23. Afterwards, ring-opening and intramolecular Friedel–Crafts reactions should enable the formation of indene 20 or naphthalene 21. With the gold catalyst, the formation of indene 19 indicated that electrophilic

Gold-catalyzed naphthalene functionalization

• Pedro J. Pérez,
• M. Mar Díaz-Requejo and
• Iván Rivilla

Beilstein J. Org. Chem. 2011, 7, 653–657, doi:10.3762/bjoc.7.77

• bond. In addition, no byproducts derived from carbene coupling were observed. Keywords: carbene insertion; copper catalysts; diazoacetates; gold catalysts; naphthalene functionalization; selective insertion; Introduction At the end of the nineteenth century, Buchner discovered [1] the thermal and

• observed with other metal-based catalysts [4][5][6]. The above transformation with rhodium-based catalysts [7][8] has also been investigated with naphthalene as a substrate. In this case, Teyssié and co-workers showed that it could be converted, using t-butyl diazoacetate, into norcaradiene type

• derivatives, formed by the cyclopropanation of one of the double bonds of the naphthalene ring. Later, Müller and co-workers [9] showed the effect of a series of Rh2(L-L)4 in the same transformation but with ethyl diazoacetate as the carbene source. A mixture of the products (2a–d) arising from

Synthesis of 5-(2-methoxy-1-naphthyl)- and 5-[2-(methoxymethyl)-1-naphthyl]-11H-benzo[b]fluorene as 2,2'-disubstituted 1,1'-binaphthyls via benzannulated enyne–allenes

• Yu-Hsuan Wang,
• Joshua F. Bailey,
• Jeffrey L. Petersen and
• Kung K. Wang

Beilstein J. Org. Chem. 2011, 7, 496–502, doi:10.3762/bjoc.7.58

• spectrometer, the signals of the methylene hydrogens on the five-membered ring could be discerned as an AB system at δ 4.27 (J = 21 Hz) and 4.25 (J = 21 Hz). The rotational barrier of BINOL as a member of the 2,2'-disubstituted 1,1'-binaphthyls was determined to be 37.2 kcal/mol at 195 °C in naphthalene

• -butoxide (1.0 M) in 2-methyl-2-propanol, lithium diisopropylamide (LDA, 2.0 M) in heptane/THF/ethylbenzene, Pd(PPh3)2Cl2, Pd(PPh3)4, copper(I) iodide, triethylamine, 1.0 M BH3·THF solution in THF, 1-ethynylnaphthalene (18a), 2-methoxy-1-naphthaldehyde, 1-bromo-2-(methoxymethyl)naphthalene, (trimethylsilyl

Anion–π interactions influence pK_a values

• Christopher J. Cadman and
• Anna K. Croft

Beilstein J. Org. Chem. 2011, 7, 320–328, doi:10.3762/bjoc.7.42

• model systems 1–5, based on 1,8-disubstituted naphthalene (Figure 1). Such model systems have already been utilised to great effect by Cozzi and co-workers to probe π–π interactions [25][26]. Related models have also proven effective in exploring neighbouring group interactions in reactive systems, such

• corroborated in the solid state by the X-ray crystal structure of compound 4, which shows the structure as having the substituted aromatic ring roughly perpendicular to the naphthalene rings. These factors render the structures 1–5 suitable for the current study. Compounds 1–5 were titrated with TBAH to

• and is accompanied by a ring critical point from the 6-membered ring made from the additional atoms of the naphthalene moiety. The ρ value is, as can be surmised from the lower interaction energy, lower for the bond critical point between H and C for 2(a) (0.0193 e·bohr−3) than for that between H and

Supramolecular FRET photocyclodimerization of anthracenecarboxylate with naphthalene-capped γ-cyclodextrin

• Qian Wang,
• Cheng Yang,
• Gaku Fukuhara,
• Tadashi Mori,
• Yu Liu and
• Yoshihisa Inoue

Beilstein J. Org. Chem. 2011, 7, 290–297, doi:10.3762/bjoc.7.38

• .7.38 Abstract γ-Cyclodextrin (CD) derivatives with a naphthalene moiety anchored to one or two of the glucose units of the CD were synthesized in order to investigate the effects of flexible and rigid capping upon complexation, as well as Förster resonance energy transfer (FRET) and photochirogenic

• behavior of anthracenecarboxylate (AC) moieties. UV–vis, circular dichroism and fluorescence spectral studies revealed that two AC molecules are simultaneously included in the modified γ-CD cavity to form a right-handed screw and also that the naphthalene cap efficiently transfers the singlet energy to AC

• Förster resonance energy transfer (FRET) sensitization. Results and Discussion Naphthalene-capped γ-CD 6 was synthesized by the reaction of 6A,6C-ditosyl-γ-CD [23] with disodium 2,6-naphthalenedicarboxylate in DMSO. An attempt to synthesize the regioisomeric 6A,6D-(2,6-naphthalenedicarboxyl)-γ-CD by

Highly substituted benzannulated cyclooctanol derivatives by samarium diiodide-induced cyclizations

• Jakub Saadi,
• Irene Brüdgam and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2010, 6, 1229–1245, doi:10.3762/bjoc.6.141

• , Ar), 51.7, 176.3 (q, s, CO2Me) ppm. IR (neat): = 3510 (br, O-H), 3100–2850 (=C-H, C-H), 1720 (C=O) cm−1. C16H22O3 (262.3): calcd: C 73.25, H 8.45; found: C 73.43, H 8.30. Methyl (2SR,4RS,4aSR)-4-hydroxy-4-methyl-8-[(1E)-propen-1-yl]-1,2,3,4,4a,7-hexahydro-naphthalene-2-carboxylate (20): 1H NMR

Self-assembly and semiconductivity of an oligothiophene supergelator

• Pampa Pratihar,
• Suhrit Ghosh,
• Vladimir Stepanenko,
• Sameer Patwardhan,
• Ferdinand C. Grozema,
• Laurens D. A. Siebbeles and
• Frank Würthner

Beilstein J. Org. Chem. 2010, 6, 1070–1078, doi:10.3762/bjoc.6.122

• these elongated fibres form interpenetrating network in which the solvent molecules are trapped [3][4]. Organogels based on various π-systems such as oligophenylenevinylenes [5] and thienylenevinylenes [6] oligophenyleneethylenes [7], phthalocyanines [8], porphyrins [9], naphthalene and perylene

β-Hydroxy carbocation intermediates in solvolyses of di- and tetra-hydronaphthalene substrates

• Jaya S. Kudavalli and
• Rory A. More O'Ferrall

Beilstein J. Org. Chem. 2010, 6, 1035–1042, doi:10.3762/bjoc.6.118

• cis and trans isomers, kcis/ktrans = 1800 in aqueous acetonitrile. This mirrors the behaviour of the acid-catalysed dehydration of cis- and trans-naphthalene-1,2-dihydrodiols to form 2-naphthol, for which kcis/ktrans = 440, but contrasts with that for solvolysis of tetrahydronaphthalene substrates, 1

• benzene, naphthalene (1,2), phenanthrene (9,10) and 3,4-dihydronaphthalene in Figure 1 [3]. The purpose of the present work was to determine whether the same differentials apply to solvolysis reactions of dihydrodiol derivatives for which one of the hydroxy groups has been converted to a more reactive

• leaving group. In the case of benzene dihydrodiol it is hard to functionalise the hydroxy group without triggering aromatisation to phenol, at least in the case of the cis-diol. The same is true of the cis-1,2-dihydrodiol of naphthalene. However, prior methylation of the 2-hydroxy group of this substrate

Pyridinium based amphiphilic hydrogelators as potential antibacterial agents

• Sayanti Brahmachari,
• Sisir Debnath,
• Sounak Dutta and
• Prasanta Kumar Das

Beilstein J. Org. Chem. 2010, 6, 859–868, doi:10.3762/bjoc.6.101

• have synergistically led to a surge in the development of tailor-made LMWHs. The presence of an aromatic ring (for example, phenyl, naphthalene, N-fluorenyl-9-methoxycarbonyl (Fmoc), indole, pyridine) in small molecule gelator is known to have crucial influence in inducing self-aggregation towards