Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid

• Kaj M. van Vliet,
• Nicole S. van Leeuwen,
• Albert M. Brouwer and
• Bas de Bruin

Beilstein J. Org. Chem. 2020, 16, 398–408, doi:10.3762/bjoc.16.38

• form in case of fac-[Ir(ppy)3]), which was proven by mass spectrometry and EPR spectroscopy for one of the catalysts (N,N-5,10-di(2-naphthalene)-5,10-dihydrophenazine) used in this work. The generation of HCl resulting from lactone formation could be an additional problem for organometallic photoredox

• -yl)-10-(naphthalen-1-yl)-10H-phenoxazine instead of [Ir(ppy)3] as the photoredox catalyst had no beneficial effect on the yield or conversion, and also led to the formation of a precipitate. However, the precipitate that was formed when the organic dye 5,10-di(naphthalene-2-yl)-5,10-dihydrophenazine

Synthesis and herbicidal activities of aryloxyacetic acid derivatives as HPPD inhibitors

• Man-Man Wang,
• Hao Huang,
• Lei Shu,
• Jian-Min Liu,
• Jian-Qiu Zhang,
• Yi-Le Yan and
• Da-Yong Zhang

Beilstein J. Org. Chem. 2020, 16, 233–247, doi:10.3762/bjoc.16.25

• , the introduction of large groups on the benzene ring appears to be beneficial to the activity and deserves further structural optimization. The herbicidal activities of compounds containing other aromatic rings, compound II and III bearing a pyridine ring and a naphthalene ring, were examined. The

Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series

• Sarah L. Skraba-Joiner,
• Carter J. Holt and
• Richard P. Johnson

Beilstein J. Org. Chem. 2019, 15, 2655–2663, doi:10.3762/bjoc.15.258

• favoring the 2,2'-isomer 9 (97%) at equilibrium [26]. Aryl shifts occur readily in naphthalene, with beta-substitution favored at equilibrium. Skeletal rearrangements of fused arene rings are also possible and can proceed through several mechanisms. The first example was reported by Dansi and Salvioni in

Experimental and computational electrochemistry of quinazolinespirohexadienone molecular switches – differential electrochromic vs photochromic behavior

• Eric W. Webb,
• Jonathan P. Moerdyk,
• Kyndra B. Sluiter,
• Benjamin J. Pollock,
• Amy L. Speelman,
• Eugene J. Lynch,
• William F. Polik and
• Jason G. Gillmore

Beilstein J. Org. Chem. 2019, 15, 2473–2485, doi:10.3762/bjoc.15.240

• photochemistry of two closely related and more reducible quinazolinespirohexadienones (QSHDs), wherein the naphthalene of the PSHD is replaced with a quinoline. In the present work, we report our investigation of the electrochemistry of these asymmetric QSHDs. In addition to the short wavelength and photochromic

• substrates [11][12][13][14][15], or vinylcarbazole or alkoxystyrene derivatives for radical cation cylcloaddition and polymerization reactions [16][17][18][19][20]). We thus proposed the replacement of the naphthalene in 1a with a more electron-deficient quinoline ring. Due to the saturated spirocyclic

• voltammogram in Figure 4. In terms of achieving more potent photooxidants through the exchange of the naphthalene ring of the PSHDs for the more electron-deficient quinoline in the QSHDs, we had expected the LW isomers to become more easily reducible, with minimal change in reduction potential for the SW

Combining the Ugi-azide multicomponent reaction and rhodium(III)-catalyzed annulation for the synthesis of tetrazole-isoquinolone/pyridone hybrids

• Gerardo M. Ojeda,
• Prabhat Ranjan,
• Pavel Fedoseev,
• Lisandra Amable,
• Upendra K. Sharma,
• Daniel G. Rivera and
• Erik V. Van der Eycken

Beilstein J. Org. Chem. 2019, 15, 2447–2457, doi:10.3762/bjoc.15.237

• rings, such as furan, benzofuran, pyrrole, benzopyrrole, thiophene, benzothiophene and naphthalene were also successfully synthesized (5d–l) in moderate to very good yields. The exceptions were the cases of indolopyridone 5i and thiazolopyridone 5k, the latter one could not be obtained even after many

Perspective isomorphs – a new classification of molecular structures based on artistic and chemical concepts

• Jannis Neumann,
• Ansgar Schnurr and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2019, 15, 2319–2326, doi:10.3762/bjoc.15.224

• . According to the viewpoint, one molecule can be assigned to different PI classes. In Figure 2 different aromatic compounds are shown. While 1,2-dihydroxybenzene is perspective isomorphic to 1,2-difluorobenzene or naphthalene, benzene and phenol can be grouped into the same PI class. These two compounds can

• to a group on the left: 1,2-dihydroxybenzene, 1,2-difluorobenzene, naphthalene. Molecules that can be allocated to a group on the right: diphenylacetylene, 4-fluorobiphenyl, benzoic acid. Molecules that can be allocated to both groups: benzene (not shown), phenol, fluorobenzene (the arrows in red and

Azologization and repurposing of a hetero-stilbene-based kinase inhibitor: towards the design of photoswitchable sirtuin inhibitors

• Christoph W. Grathwol,
• Nathalie Wössner,
• Sören Swyter,
• Adam C. Smith,
• Enrico Tapavicza,
• Robert K. Hofstetter,
• Anja Bodtke,
• Manfred Jung and
• Andreas Link

Beilstein J. Org. Chem. 2019, 15, 2170–2183, doi:10.3762/bjoc.15.214

• available naphthalene-2-ylboronic acid or (3,4-dihydronaphthalen-2-yl)boronic acid (Scheme 1). The latter was synthesized according to a literature procedure [36]. Formation of compounds 2b–h was accomplished through Heck coupling of aryl bromides with the appropriate styrenes (Scheme 2) [37]. Compounds 2b

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• strongly [64]. Upon addition of diisopropylethylamine (DIEA) to the solution of [2]catenane 17a, the color of the solution changed from colorless to slightly yellow due to the strong charge transfer between the naphthalene ring of dinaphtho-24-crown-8 (DN24C8) and the naphthalenediimide (NDI) unit

Friedel–Crafts approach to the one-pot synthesis of methoxy-substituted thioxanthylium salts

• Kenta Tanaka,
• Yuta Tanaka,
• Mami Kishimoto,
• Yujiro Hoshino and
• Kiyoshi Honda

Beilstein J. Org. Chem. 2019, 15, 2105–2112, doi:10.3762/bjoc.15.208

• excellent yields (3f–h). The benzoyl chlorides bearing a variety of halogens were suitable for this reaction (3i–n). Although naphthalene is a sterically large group, the reaction proceeded smoothly (3o). The diaryl sulfide with ethoxy substituents furnished the corresponding product in moderate yield (3p

• , 53.13; H, 3.90. found: C, 52.80; H, 4.001. For the synthesis of 9-(naphthalene-1-yl)-1,3,6,8-tetramethoxythioxanthylium trifluoromethanesulfonate (3o) To a solution of 1-naphthoic acid (0.1746 g, 1.0 mmol) in dry CH2Cl2 (2.5 mL) at 0 °C under N2 (COCl)2 (0.100 mL, 1.2 mmol) was dropwise added. After the

Naphthalene diimides with improved solubility for visible light photoredox catalysis

• Barbara Reiß and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 2043–2051, doi:10.3762/bjoc.15.201

• Barbara Reiss Hans-Achim Wagenknecht Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany 10.3762/bjoc.15.201 Abstract Five core-substituted naphthalene diimides bearing two dialkylamino groups were synthesized as potential visible

• light photoredox catalysts and characterized by methods of optical spectroscopy and electrochemistry in comparison with one unsubstituted naphthalene diimide as reference. The core-substituted naphthalene diimides differ by the alkyl groups at the imide nitrogens and at the nitrogens of the two

• solubilities. The electron-donating diaminoalkyl substituents together with the electron-deficient aromatic core of the naphthalene diimides increase the charge-transfer character of their photoexcited states and thus shift their absorption into the visible light (500–650 nm). The excited state reduction

Archangelolide: A sesquiterpene lactone with immunobiological potential from Laserpitium archangelica

• Silvie Rimpelová,
• Michal Jurášek,
• Lucie Peterková,
• Jiří Bejček,
• Vojtěch Spiwok,
• Miloš Majdl,
• Michal Jirásko,
• Miloš Buděšínský,
• Juraj Harmatha,
• Eva Kmoníčková,
• Pavel Drašar and
• Tomáš Ruml

Beilstein J. Org. Chem. 2019, 15, 1933–1944, doi:10.3762/bjoc.15.189

• fluorescent 5-(dimethylamino)-N-(prop-2-yn-1-yl)naphthalene-1-sulfonamide (synthesized according to [18]) using CuI and TBTA [19] catalysis. All of the synthesized compounds were thoroughly described by NMR (Supporting Information File 1, Table S1), IR, optical rotation (Supporting Information File 1, section

• . Synthesis of 11-(5-(4-((5-(dimethylamino)naphthalene-1-sulfonamido)methyl)-1H-1,2,3-triazol-1-yl)pentanoylarchangelolide (5) To a solution of azidovalerate 4 (40 mg, 0.063 mmol) and 5-(dimethylamino)-N-(prop-2-yn-1-yl)naphthalene-1-sulfonamide (20 mg, 0.07 mmol) in THF (3 mL), CuI (50 µL of 1 M water

Tautomerism as primary signaling mechanism in metal sensing: the case of amide group

• Vera Deneva,
• Georgi Dobrikov,
• Aurelien Crochet,
• Daniela Nedeltcheva,
• Katharina M. Fromm and
• Liudmil Antonov

Beilstein J. Org. Chem. 2019, 15, 1898–1906, doi:10.3762/bjoc.15.185

• , Switzerland 10.3762/bjoc.15.185 Abstract The concept for sensing systems using the tautomerism as elementary signaling process has been further developed by synthesizing a ligand containing 4-(phenyldiazenyl)naphthalene-1-ol as a tautomeric block and an amide group as metal capturing antenna. Although it has

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

• the shrunken cavity caused by intramolecular hydrogen bonds in the latter tetralactam macrocycle. The binding of the isophthalamide-based macrocycle is mainly driven by hydrogen bonds and electrostatic interactions. This naphthalene-based macrocycle has similar binding affinities to all the three

• 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

• distance: 2.21, 2.38 and 2.46 Å). C–H···π interactions (H···π distance: 2.75 and 2.83 Å) between the methyl group of CH3CN and the naphthalene panels of the host are also detected. This suggests that the 2.3-dibutoxynaphthalene tetralactam macrocycle, just like other tetralactam macrocycles, may use

Fluorine-containing substituents: metabolism of the α,α-difluoroethyl thioether motif

• Andrea Rodil,
• Alexandra M. Z. Slawin,
• Nawaf Al-Maharik,
• Ren Tomita and
• David O’Hagan

Beilstein J. Org. Chem. 2019, 15, 1441–1447, doi:10.3762/bjoc.15.144

• significantly more slowly to the sulfone. When the substrate was (p-OMe)PhSCF2CH3, then the resultant (demethylated) phenol sulfoxide had an enantiomeric excess of 60%, and when the substrate was the β-substituted-SCF2CH3 naphthalene, then the enantiomeric excess of the resultant sulfoxide was 54%. There was no

• very active and outcompetes demethylation, however, that demethylation is significantly more active that the second oxidation of sulfoxides to sulfones. Incubation of naphthalene 5 with C. elegans, generated three new metabolites 11–13 which arose by oxidations at sulphur and hydroxylations of the

• naphthalene ring, as summarised in Scheme 3. These metabolites were isolated by reversed-phase HPLC and characterised by 1H and 19F NMR and mass spectrometry. This identified sulfoxides 11 and 12 as the major metabolites and a trace amount of a minor sulfone which had the general structure 13 as determined by

Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response

• Yu-Ying Wang,
• Yong Kong,
• Zhe Zheng,
• Wen-Chao Geng,
• Zi-Yi Zhao,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139

• luminescent dyes. Fluorescein, eosin Y, rose bengal, tetraphenylporphine sulfonate and sulfonated aluminum phthalocyanine were employed as classical aggregation-induced quenching dyes. 2-(p-Toluidinyl)naphthalene-6-sulfonic acid and 1-anilinonaphthalene-8-sulfonic acid were selected as representatives of

• (EY), rose bengal (RB), tetraphenylporphine sulfonate (TPPS), sulfonated aluminum phthalocyanine (AlPcS4), 2-(p-toluidinyl)naphthalene-6-sulfonic acid (2,6-TNS), 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS), phosphated tetraphenylethylene (P-TPE), sulfonated acedan (TPS), and a ruthenium(II) complex

• photons as the excitation source. The fluorescent probe simultaneously absorbs two low energy photons to reach the excited state followed by fluorescence [57]. Acedan (6-acetyl-2-(dimethylamino)naphthalene) is a well-known probe with two-photon absorption that has been utilized in two-photon microscopy

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

• the reaction carried out in solution (40% vs 6% yield). The screening of substrates showed disparate reactivities, ranging from quantitative to low (Scheme 3). Most rewarding are reactions of toluene, o-xylene, naphthalene and tetralin. Interestingly, ball milling of 4-ethylanisole provided phenol 12

• naphthalene were less reactive under the same ball milling conditions and reactions stopped at the stage of formation of product 3 and 15. One-step preparation of quinone 30 [39], was achieved by melting reactants at 140 °C for 10 min. Under these conditions, a mixture of adducts 3 and 30 (1.5:1 ratio) was

Self-assembly behaviors of perylene- and naphthalene-crown macrocycle conjugates in aqueous medium

• Xin Shen,
• Bo Li,
• Tiezheng Pan,
• Jianfeng Wu,
• Yangxin Wang,
• Jie Shang,
• Yan Ge,
• Lin Jin and
• Zhenhui Qi

Beilstein J. Org. Chem. 2019, 15, 1203–1209, doi:10.3762/bjoc.15.117

• Materials & Engineering (IBME), Northwestern Polytechnical University, Xi’an, Shaanxi 710072, P. R. China 10.3762/bjoc.15.117 Abstract The synthesis of conjugates of perylene diimide (PDI) and naphthalene diimide (NDI) modified with two benzo-21-crown-7 ethers (B21C7) are herein described. Their self

• with their linear glycol chain counterparts, B21C7 shows great potential to be an easy-to-accessed building block to probe the non-covalent interactions and chemical transformations influenced by water molecules. Perylene diimide (PDI) and naphthalene diimide (NDI) are polycyclic aromatic chromophores

• × 10−4 M. Synthetic route of perylene- and naphthalene-crown macrocycle conjugates 1 and 2. Supporting Information Supporting Information File 388: Experimental and analytical data. Acknowledgements We gratefully acknowledge financial support from the Thousand Talents Program of China, Postdoctoral

Mechanochemistry of supramolecules

• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2019, 15, 881–900, doi:10.3762/bjoc.15.86

• –acceptor [2]rotaxanes such as 19 through liquid-assisted mechanochemical milling (Figure 9). The donor–acceptor interaction between the electron-deficient naphthalene diimide moiety and the electron-rich naphthalene moieties embedded in the macrocyclic polyethers played the vital role for the construction

Coordination chemistry and photoswitching of dinuclear macrocyclic cadmium-, nickel-, and zinc complexes containing azobenzene carboxylato co-ligands

• Jennifer Klose,
• Tobias Severin,
• Peter Hahn,
• Alexander Jeremies,
• Jens Bergmann,
• Daniel Fuhrmann,
• Jan Griebel,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Org. Chem. 2019, 15, 840–851, doi:10.3762/bjoc.15.81

• physicochemical properties of the bound guest molecules are also greatly affected. Thus, complexation of naphthalene diimide carboxylato ligands leads to a substantial (>95%) quenching of the diimide fluorescence [5], and incorporation of a Fe(CpCO2H)2 unit leads to a significant anodic shift of the metallocene’s

Azologization of serotonin 5-HT₃ receptor antagonists

• Karin Rustler,
• Galyna Maleeva,
• Piotr Bregestovski and
• Burkhard König

Beilstein J. Org. Chem. 2019, 15, 780–788, doi:10.3762/bjoc.15.74

• properties of direct azologization to azo-extension, two additional derivatives of the in vitro most promising naphthalene azopurine 16c were synthesized either by keeping the original thioether (Scheme 5) or replacing it by an amide bond (Scheme 6) known as common structural feature of 5-HT3R antagonists

• , two azo-extended purine derivatives 23 and 28 were synthesized resulting in excellent photochromic properties. Figure 1 compares exemplarily the UV–vis absorption spectra of the naphthalene-azo-purine 16c (left) and its azo-extended azobenzene thioether purine 23 (right). The determination of the

Selective benzylic C–H monooxygenation mediated by iodine oxides

• Kelsey B. LaMartina,
• Haley K. Kuck,
• Linda S. Oglesbee,
• Asma Al-Odaini and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2019, 15, 602–609, doi:10.3762/bjoc.15.55

• aromatization was observed, suggesting that monooxygenated products are able to react further. We propose that acetoxylated tetrahydronaphthalene eliminates acetic acid to yield dihydronaphthalene, which can be further oxidized by two electrons to yield the stable naphthalene ring. Minisci and co-workers also

Oxidative radical ring-opening/cyclization of cyclopropane derivatives

• Yu Liu,
• Qiao-Lin Wang,
• Zan Chen,
• Cong-Shan Zhou,
• Bi-Quan Xiong,
• Pan-Liang Zhang,
• Chang-An Yang and
• Quan Zhou

Beilstein J. Org. Chem. 2019, 15, 256–278, doi:10.3762/bjoc.15.23

• different amount of NBS (N-bromosuccinimide). The corresponding CF3-substituted naphthalene 32 could be obtained in 69% yield when the product 31a was oxidized by 3 equiv of NBS (Scheme 9, reaction a). When the amount of NBS was increased to 6 equiv under identical conditions, the CF3-substituted

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

1,8-Bis(dimethylamino)naphthyl-2-ketimines: Inside vs outside protonation

• A. S. Antonov,
• A. F. Pozharskii,
• P. M. Tolstoy,
• A. Filarowski and
• O. V. Khoroshilova

Beilstein J. Org. Chem. 2018, 14, 2940–2948, doi:10.3762/bjoc.14.273

• -arylketimines of 1,8-bis(dimethylamonio)naphthalene with a different number of methoxy groups in an aromatic substituent were investigated in solution by NMR (acetone, DMSO, MeCN), in solid state by X-ray analysis and in the gas phase by DFT calculations. Both mono- and diprotonated species were considered. It

• rotation of the NH2+ fragment in dications. Keywords: hydrogen bond; imine; NMR; proton sponge; superbase; Introduction It is well known that the extremely high basicity of 1,8-bis(dimethylamino)naphthalene (1, DMAN; pKa = 12.1 in H2O [1][2], 18.62 in MeCN [3], 7.5 in DMSO [4]) and its derivatives

• of the Z-form through formation of a stronger hydrogen bond between the DMSO molecule and the NHb proton [11], which is sterically unhindered and accessible for the solvent. Indeed, X-ray data and quantum chemical calculations show that phenyl and naphthalene rings are almost perpendicular (Figure 2

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• strength, the high surface area may play a role in catalysis. The catalyst was reused up to five cycles [69]. Pourmousavi et al. [70] found that sulfonated polynaphthalene 121 synthesized from naphthalene (119) shows high catalytic activities in the one-pot preparation of amidoalkyl naphthols 50. The

• sulfonated polynaphthalene can be achieved in two steps: (a) polymerization of naphthalene (119) in nitrobenzene using FeCl3 as reagent (b) sulfonation of polynaphthalene (120) with chlorosulfonic acid in dichloromethane (Scheme 22). Amidoalkylnaphthol derivatives 50 were synthesized using catalyst 121 under