An efficient Pd–NHC catalyst system in situ generated from Na₂PdCl₄ and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

• Nan Sun,
• Meng Chen,
• Liqun Jin,
• Wei Zhao,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2017, 13, 1735–1744, doi:10.3762/bjoc.13.168

• -PEG1900-Im was heated with various organic bromides (2-(bromomethyl)pyridine, benzyl bromide and 1-(bromomethyl)naphthalene) to generate the corresponding imidazolium salts L1–L3 under solvent-free conditions. All imidazolium salts were water-soluble and air-stable. The resulted salts L1–L3 were

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

A novel approach to oxoisoaporphine alkaloids via regioselective metalation of alkoxy isoquinolines

• Benedikt C. Melzer and
• Franz Bracher

Beilstein J. Org. Chem. 2017, 13, 1564–1571, doi:10.3762/bjoc.13.156

• pyridine nitrogen), can very well promote a directed remote metalation. To test our hypothesis, we performed two more D2O quenching experiments with naphthalene analogues of esters 10 and amide 12. The methyl ester analogue 15 was obtained by Suzuki cross-coupling of naphthalene-1-boronic acid (13) and

• only in the ortho-position to the benzamide residue (C-2 of the naphthalene ring system), but not in the peri-position (C-8 of the naphthalene). Consequently, further attempts to initialize the cyclization of arylisoquinolines 10c and 12 to the oxoisoaporphine alkaloid bianfugecine (6, Scheme 5) by a

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

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

A new class of organogelators based on triphenylmethyl derivatives of primary alcohols: hydrophobic interactions alone can mediate gelation

• Wangkhem P. Singh and
• Rajkumar S. Singh

Beilstein J. Org. Chem. 2017, 13, 138–149, doi:10.3762/bjoc.13.17

• ][24]. Similar is the case for π-stacking interaction (seen in naphthalene, anthracene, pyrene, perylene, etc.) which has been mostly used in combination with other types of secondary interactions in the discovery of many gelators [25][26]. This holds true for many other non-covalent interactions as

• interactions between the alkyl chains and the triphenylmethyl moieties. Compared to other planar aromatic molecules (such as naphthalene, anthracene, perylene, etc.), the triphenylmethyl moiety as a whole exhibits a non-planar geometry, hence π-stacking interaction between triphenylmethyl moieties may not be

cis-Diastereoselective synthesis of chroman-fused tetralins as B-ring-modified analogues of brazilin

• Dimpee Gogoi,
• Runjun Devi,
• Pallab Pahari,
• Bipul Sarma and
• Sajal Kumar Das

Beilstein J. Org. Chem. 2016, 12, 2816–2822, doi:10.3762/bjoc.12.280

• group of 5 and/or 9, leading to the formation of a stable 3°carbocation that can undergo further dehydration reactions until full aromatization to the naphthalene ring is achieved. This study would serve to help us to find the real scenario. Finally, in the presence of Lewis/Brønsted acids, substrates 6

Direct arylation catalysis with chloro[8-(dimesitylboryl)quinoline-κN]copper(I)

• Sem Raj Tamang and
• James D. Hoefelmeyer

Beilstein J. Org. Chem. 2016, 12, 2757–2762, doi:10.3762/bjoc.12.272

• Sem Raj Tamang James D. Hoefelmeyer Department of Chemistry, University of South Dakota, 414 E. Clark St., Vermillion, SD 57069, USA 10.3762/bjoc.12.272 Abstract We report direct arylation of arylhalides with unactivated sp2 C–H bonds in benzene and naphthalene using a copper(I) catalyst

• . Activation of the sp2 C–H bonds in naphthalene was possible as well. The reaction of iodobenzene in neat naphthalene at 85 °C using 0.2 mol % catalyst and 3 equivalents KO(t-Bu) gave a ≈2:1 ratio of 1-phenylnaphthalene and 2-phenylnaphthalene in a total yield of 43% (Table 1, entry 18). The observed

• substitution ratio is typical of substitutions on naphthalene under kinetic control that tend to favor the alpha C–H bonds due better resonance stabilization effects [53]. Importantly, we note the alpha protons are slightly more acidic than the beta protons [54]. The mechanism of Cu catalyzed coupling

Determination of the absolute stereostructure of a cyclic azobenzene from the crystal structure of the precursor containing a heavy element

• Reji Thomas and
• Nobuyuki Tamaoki

Beilstein J. Org. Chem. 2016, 12, 2211–2215, doi:10.3762/bjoc.12.212

• structure, with a photoisomerizable azobenzene unit linked to a substituted or unsubstituted aromatic unit such as naphthalene or benzene. Generally the molecules are of three categories (i) achiral (irrespective of the isomerized state of the azobenzene, i.e., E or Z), (ii) chiral in E-state and achiral in

• polygonal finger print texture [45]. Molecule (E)-1 contains a 2,6-dibromo-1,5-dihydroxynaphthalene part linked to an azobenzene unit through bismethylene spacers. The constricted rotation of the naphthalene unit in the cyclic structure gives planar chirality to this molecule with separable enantiomers. The

• presence of the bromine substitution in the naphthalene unit gives an added advantage in determining the absolute stereostructure of the separated enantiomers. The determination of the absolute stereostructure of one of the enantiomers of (E)-1 by X-ray diffraction has been presented in our previous report

Stereoselective synthesis of fused tetrahydroquinazolines through one-pot double [3 + 2] dipolar cycloadditions followed by [5 + 1] annulation

• Xiaofeng Zhang,
• Kenny Pham,
• Shuai Liu,
• Marc Legris,
• Alex Muthengi,
• Jerry P. Jasinski and
• Wei Zhang

Beilstein J. Org. Chem. 2016, 12, 2204–2210, doi:10.3762/bjoc.12.211

• ). Compound 7b was an exception, which was obtained in a trace amount. It was found that replacing maleimides 6 with other activated alkenes such as dimethyl maleate, benzoquinone, naphthalene-1,4-dione, and maleonitrile failed to afford products 7q–t, probably due to unfavorable stereoelectronic effects

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

• Katrina Tait,
• Oday Alrifai,
• Rebecca Boutin,
• Jamie Haner and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 2189–2196, doi:10.3762/bjoc.12.209

• , the dihydronaphthalenols can fully aromatize to form various substituted naphthalene derivatives 11. This has been accomplished through acid catalysis with various alcohol nucleophiles [31]. The last type of predicted ring opening (type 3) which has not yet been observed involves the attack of the

• reaction did not proceed and the starting material was recovered. The effect of a palladium(II) catalyst was then investigated (Table 1, entries 4–9), producing variable yields of substituted naphthalene 11a. While attempts using Pd(OAc)2 (Table 1, entry 4) and PdCl2(PPh3)2 (Table 1, entry 5) were

• unsuccessful, palladium(II) catalysts in the absence of a triphenylphosphine ligand were more promising (Table 1, entries 6–9). The palladium(II) catalyst PdCl2(CH3CN)2 generated a high yield of substituted naphthalene 11a after only 24 hours and was chosen to further optimize reaction conditions. When the

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• known, fluorinated n-type materials are less common [13][30][31]. Nevertheless, fluorinated n-type materials have been shown to exhibit promising characteristics in devices. For instance, the addition of fluorinated groups to naphthalene diimide (NDI) and perylene diimide (PDI) derivatives increased the

Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

• Élise Euvrard,
• Nadia Morin-Crini,
• Coline Druart,
• Justine Bugnet,
• Bernard Martel,
• Cesare Cosentino,
• Virginie Moutarlier and
• Grégorio Crini

Beilstein J. Org. Chem. 2016, 12, 1826–1838, doi:10.3762/bjoc.12.172

• PAHs: naphthalene (NAP), acenaphthene (ACE), acenaphthylene (ACY), fluorene (FLU), phenanthrene (PHE), anthracene (ANT), fluoranthene (FLT) and pyrene (PYR); eight heavy PAHs: benz[a]anthracene (BaANT), chrysene (CHY), benzo[b]fluoranthene (BbFLT), benzo[k]fluoranthene (BkFLT), benzo[a]pyrene (BaPYR

Ring-whizzing in polyene-PtL₂ complexes revisited

• Oluwakemi A. Oloba-Whenu,
• Thomas A. Albright and
• Chirine Soubra-Ghaoui

Beilstein J. Org. Chem. 2016, 12, 1410–1420, doi:10.3762/bjoc.12.135

• , octafluorooctatetraene, 6-radialene, pentalene, phenalenium+, naphthalene and octafluoronaphthalene. The HOMO of a d10 ML2 group (with b2 symmetry) interacting with the LUMO of the polyene was used as a model to explain the occurrence of minima and maxima on the potential energy surface. Keywords: d10 metal complexes

• complexes [64][65][66][67] are akin to 45. Our calculated barrier of 14.7 kcal/mol via 47 seems a bit too low. The measured barrier in two Pd(tmeda) complexes was 21.4 and 21.6 kcal/mol [66]. No signs of fluxionality was found in a substituted phenalenium–Pt(PPh3)2+ complex [67]. Naphthalene and anthracene

• fusion. Our calculations on octafluoronaphthalene–Ni(dpe) and –Pt(dpe) (as well as naphthalene–Pt(dpe) itself) are in good agreement with experiment. A top view of the structure is shown by 48 in Figure 14. This offers a good overlap between the LUMO in C10F8, 49, and the b2 HOMO, 5, in Pt(dpe). It was

Cationic Pd(II)-catalyzed C–H activation/cross-coupling reactions at room temperature: synthetic and mechanistic studies

• Takashi Nishikata,
• Alexander R. Abela,
• Shenlin Huang and
• Bruce H. Lipshutz

Beilstein J. Org. Chem. 2016, 12, 1040–1064, doi:10.3762/bjoc.12.99

• . Generally, it is difficult to efficiently control the selectivity between the C2 and C8 positions in naphthalene rings towards a single isomeric C–H activation product [163][174][185][186][187][188][189]. Fujiwara–Moritani reactions Following these results on biaryl constructions via C–H activation at room

Synthesis and fluorosolvatochromism of 3-arylnaphtho[1,2-b]quinolizinium derivatives

• Phil M. Pithan,
• David Decker,
• Manlio Sutero Sardo,
• Giampietro Viola and
• Heiko Ihmels

Beilstein J. Org. Chem. 2016, 12, 854–862, doi:10.3762/bjoc.12.84

• ). The latter was synthesized from the known 2-bromo-6-(bromomethyl)naphthalene (2) which was prepared in two steps according to published procedures [26] from commercially available methyl 6-bromo-2-naphthoate. The reaction of the (bromomethyl)naphthalene 2 with (1,3-dioxolan-2-yl)pyridine yielded the N

• even the intermolecular electron transfer reactions between electron rich aromatic compounds, such as naphthalene and phenanthrene, and the excited benzo[b]quinolizinium fluorophore were shown to be efficient processes [37]. The biaryl derivatives 6b–e exhibit fluorosolvatochromism that is

A convenient route to symmetrically and unsymmetrically substituted 3,5-diaryl-2,4,6-trimethylpyridines via Suzuki–Miyaura cross-coupling reaction

• Dariusz Błachut,
• Joanna Szawkało and
• Zbigniew Czarnocki

Beilstein J. Org. Chem. 2016, 12, 835–845, doi:10.3762/bjoc.12.82

• the phenyl rings (or naphthalene ring for 26) with three methyl groups of the pyridine ring. Consequently, the inhibited rotation of the phenyl rings led to the formation of stable diastereomeric atropisomers which could be detected in NMR spectroscopy. The interconversion barrier is probably

Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors

• Minh Anh Truong and
• Koji Nakano

Beilstein J. Org. Chem. 2016, 12, 805–812, doi:10.3762/bjoc.12.79

• ']difurans and benzo[1,2-b:6,5-b']difurans) and studied their structure–property relationship [33][34]. Furthermore, naphthodifurans with a fused-naphthalene between two furan rings have been developed as organic semiconductors for OFETs [19][20]. In particular, the naphtho[2,1-b:6,5-b']difuran derivative 2

Iridium/N-heterocyclic carbene-catalyzed C–H borylation of arenes by diisopropylaminoborane

• Mamoru Tobisu,
• Takuya Igarashi and
• Naoto Chatani

Beilstein J. Org. Chem. 2016, 12, 654–661, doi:10.3762/bjoc.12.65

•  3, entry 5). Naphthalene also underwent borylation with 1g at the less hindered 2-position (Table 3, entry 6). Our protocol was performed on a gram scale without any difficulty using a lower loading of the iridium catalyst (Scheme 2, top). Using 1g as the boron source in C–H borylation reactions has

A journey in bioinspired supramolecular chemistry: from molecular tweezers to small molecules that target myotonic dystrophy

• Steven C. Zimmerman

Beilstein J. Org. Chem. 2016, 12, 125–138, doi:10.3762/bjoc.12.14

• expanded as in molecular tweezer (clip) 17 (Figure 6), but interestingly, this compound is not active whereas the 1,8-substituted naphthalene is, providing a clip that works by an induced fit mechanism (structure not shown) [28]. The Nolte group went well beyond the simple molecular clip architecture with

• . Earlier work by Jean-Marie Lehn and coworkers showed that bisacridine 25, which they called cyclobisintercalators, selectively bound DNA hairpins [46]. The same compound was found to selectively photo-cleave abasic sites in DNA [47]. Teulade-Fichou et al. reported that 25 (and especially the naphthalene

Facile synthesis of 4H-chromene derivatives via base-mediated annulation of ortho-hydroxychalcones and 2-bromoallyl sulfones

• Srinivas Thadkapally,
• Athira C. Kunjachan and
• Rajeev S. Menon

Beilstein J. Org. Chem. 2016, 12, 16–21, doi:10.3762/bjoc.12.3

• . Polycyclic aromatic hydrocarbon frameworks (naphthalene and anthracene rings) as well as a representative heterocyclic ring (furan) may be incorporated into the 4H-chromene skeleton product by using chalcones (7c, 7d, and 7e, respectively) functionalized with these moieties. Disappointingly, attempts to

Comparison of the catalytic activity for the Suzuki–Miyaura reaction of (η⁵-Cp)Pd(IPr)Cl with (η³-cinnamyl)Pd(IPr)(Cl) and (η³-1-t-Bu-indenyl)Pd(IPr)(Cl)

• Patrick R. Melvin,
• Nilay Hazari,
• Hannah M. C. Lant,
• Ian L. Peczak and
• Hemali P. Shah

Beilstein J. Org. Chem. 2015, 11, 2476–2486, doi:10.3762/bjoc.11.269

• added 950 μL of a MeOH stock solution, containing 0.5263 M aryl chloride, 0.5525 M boronic acid, 0.5789 M KOt-Bu and 0.2632 M naphthalene. The vial was then heated using an aluminum block heater set to 25 °C. After thermal equilibration, the reaction was initiated via the addition of 50 μL of the

• determined by comparison of the GC responses of product and the internal naphthalene standard. Biaryl products were initially synthesized using literature procedures [15], identified using NMR spectroscopy by comparison to the literature chemical shifts [11] and then these pure samples used to generate

• needle. To the vial was added 950 μL of a MeOH stock solution, containing 0.5263 M aryl chloride, 0.5525 M boronic acid and 0.2632 M naphthalene. The vial was then heated using an aluminum block heater set to 25 °C. After thermal equilibration, the reaction was initiated via the addition of 50 μL of the

Supramolecular chemistry: from aromatic foldamers to solution-phase supramolecular organic frameworks

• Zhan-Ting Li

Beilstein J. Org. Chem. 2015, 11, 2057–2071, doi:10.3762/bjoc.11.222

• , even at 150 °C in DMF. Encouraged by the above work, Junli Hou, who is currently a professor at Fudan University, prepared naphthalene-incorporated oligo(ethylene glycols) 12a–g [25] (Scheme 6). UV–vis, 1H NMR, and fluorescence experiments in chloroform–acetonitrile binary solvents revealed that the

• naphthalene units in longer 12f–h stacked intramolecularly to induce the oligomeric chains to form a helical conformation at high acetonitrile content (Scheme 6). The compact helical conformation gave rise to a cavity similar to that of 18-crown-6 and thus could complex ammonium or ethane-1,2-diaminium in

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• -workers [188] have reported the synthesis of the naphthalene-diimide-based cyclophane 311 for understanding supramolecular interactions by metal ions (Figure 11). [3 + 2 + 1] Cycloaddition (Dötz benzannulation): In 2003, Wulff and co-workers [189] synthesized cyclophane derivatives using the Dötz

Synthesis and surface grafting of a β-cyclodextrin dimer facilitating cooperative inclusion of 2,6-ANS

• Lars W. Städe,
• Thorbjørn T. Nielsen,
• Laurent Duroux,
• Reinhard Wimmer,
• Kyoko Shimizu and
• Kim L. Larsen

Beilstein J. Org. Chem. 2015, 11, 514–523, doi:10.3762/bjoc.11.58

• coplanar arrangement of the aromatic rings makes 2,6-ANS an excellent guest molecule, the dimensions of 2,6-ANS exceed the dimensions of the β-CD cavity and, therefore, potentially allow for formation of a 2:1 complex. This behavior has previously been reported for parent β-CD with the naphthalene

• derivatives, 2-(N-methylanilino)naphthalene-6-sulfonic acid (2,6-MANS) and 2-(p-toluidinyl)naphthalene-6-sulfonic acid (2,6 TNS) [23]. These derivatives differ from 2,6-ANS only by having a methyl substitution at the aniline moiety (Figure 2). In the relevant study [23], the formation of a stable 2:1 complex

• was ascribed to the protection of these moieties from the aqueous solution by inclusion in the β-CD cavity in an equatorial approach, resulting in the inclusion of the naphthalene and anilino moieties in each of their respective β-CD cavities. The study [23] also included 2,6-ANS for which only a 1:1