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

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