Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization

• Jacques Lalevée,
• Sofia Telitel,
• Pu Xiao,
• Marc Lepeltier,
• Frédéric Dumur,
• Fabrice Morlet-Savary,
• Didier Gigmes and
• Jean-Pierre Fouassier

Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83

• dye Vi [61][62] or an anthracene derivative (e.g. bis[(triisopropylsilyl)ethynyl]anthracene) [54][55] as PIC, Ph2I+ as eA and TTMSS as Add (see the simplified Scheme 9 based on Scheme 6). Using violanthrone-79/Ph2I+/TTMSS allowed, for the first time, the formation of an initiating cationic species

• under a red laser line exposure at 635 nm. This result was very important as cationic polymerization in these irradiation conditions was not possible previously. Changing Vi or the anthracene derivative for a hydrocarbon (e.g. pyrene, naphthacene, pentacene) allows a tunable absorption of the system

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

• aromatic guests under controlled, homogenous reaction conditions. The quantum yields for unsubstituted anthracene, acenaphthylene, and coumarin complexed in these γ-CD thioethers were found to be up to 10 times higher than in the non-complexed state. The configuration of the photoproduct reflected the

• -to-head dimer. The degree of complexation of coumarin could be increased by employing the salting out effect. Keywords: acenaphthylene; anthracene; coumarin; cyclodextrins; photodimerization; quantum yield; stereoselectivity; Introduction Photochemical reactions have been considered highly

• 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

Integrating reaction and analysis: investigation of higher-order reactions by cryogenic trapping

• Skrollan Stockinger and
• Oliver Trapp

Beilstein J. Org. Chem. 2013, 9, 1837–1842, doi:10.3762/bjoc.9.214

• presented. The reaction and the analytical separation are combined in a single experiment to investigate the Diels–Alder reaction of benzenediazonium-2-carboxylate as a benzyne precursor with various anthracene derivatives, i.e. anthracene, 9-bromoanthracene, 9-anthracenecarboxaldehyde and 9

• our novel ocRGC setup, we chose the cycloaddition of benzyne with anthracene derivatives in a typical Diels–Alder-reaction (Scheme 1) as a model reaction. This reaction seemed suitable because of the volatility of all reactants and products and the required reaction temperature, which is in an

• , we chose to inject the heat-labile benzenediazonium-2-carboxylate after the anthracene derivative, because we expected that the thermally formed benzyne would be surrounded by the anthracene derivative, and an optimal conversion should occur. Surprisingly, the inverse injection order leads to a

Mechanistic studies on the CAN-mediated intramolecular cyclization of δ-aryl-β-dicarbonyl compounds

• Brian M. Casey,
• Dhandapani V. Sadasivam and
• Robert A. Flowers II

Beilstein J. Org. Chem. 2013, 9, 1472–1479, doi:10.3762/bjoc.9.167

• observation that 3g’ is the only product observed. A similar trend was observed for the 2-naphthyl substrate 1j. The barrier for TS2j”, which would form anthracene-derived product 2j”, is 1.5 kcal/mol higher than TS2j’ and provides a rationale for the selective formation of the phenanthrene-derived product

Thiourea-catalyzed Diels–Alder reaction of a naphthoquinone monoketal dienophile

• Carsten S. Kramer and
• Stefan Bräse

Beilstein J. Org. Chem. 2013, 9, 1414–1418, doi:10.3762/bjoc.9.158

• . Unless stated otherwise, all commercially available compounds (Acros, Fluka, Aldrich) were used as received. Ethyl 4-((tert-butyldimethylsilyl)oxy)-5,8-dimethoxy-2-methyl-10-oxo-4,4a,9a,10-tetrahydro-1H-spiro[anthracene-9,2'-[1,3]dioxolane]-9a-carboxylate (2a): In a small flask dienophile 3 (23.1 mg

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

Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents

• Hao Zhong,
• Jianwu Shi,
• Jianxun Kang,
• Shaomin Wang,
• Xinming Liu and
• Hua Wang

Beilstein J. Org. Chem. 2013, 9, 767–774, doi:10.3762/bjoc.9.87

• observed in the case of 2a, 2f and 2g (Table 1, entries 1, 6 and 7). When the bulkiness of aryl groups increased from benzene to anthracene, the yields of ring-opening products decreased from 3a (88%), to 3f (61%) and to 3g (56%). Therefore, the aryllithium reagents with bulky groups, such as

Synthesis of 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones and novel ring contraction and fusion reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] into 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones

• Lidia S. Konstantinova,
• Kirill A. Lysov,
• Ljudmila I. Souvorova and
• Oleg A. Rakitin

Beilstein J. Org. Chem. 2013, 9, 577–584, doi:10.3762/bjoc.9.62

• -anthracene-1,4-diones 4 with S2Cl2 and DABCO in chlorobenzene gave the corresponding 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones 1 and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones 2 by triethylamine addition, in high to moderate yields. The DABCO replacement for N-ethyldiisopropylamine in the

• reaction of anthracene-1,4-diones 4 led unexpectedly to the corresponding 2-thioxo-2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones 10. The reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] 1d, 2d with Et3N in chlorobenzene under reflux yielded 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones 15, 16, i.e

• ., ring contraction and fusion products. A plausible mechanism was proposed for the formation of the products. Keywords: anthracene-1,4-diones; 1H-carbazole-6,11-diones; fused thiazoles; fusion reaction; heterocycles; naphthoquinones; ring contraction; sulfur–nitrogen; Introduction The 1,4

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

Molecular solubilization of fullerene C₆₀ in water by γ-cyclodextrin thioethers

• Hai Ming Wang and
• Gerhard Wenz

Beilstein J. Org. Chem. 2012, 8, 1644–1651, doi:10.3762/bjoc.8.188

• anthracene and acenaphthylene, in water [33][34][35]. In this work, we investigated solubilization of C60 by these γ-CD thioethers (compounds 1–7 in Scheme 1) with the hope of achieving high concentrations of solubilized C60. The hydrophilic substituents at the primary face of γ-CD should increase solubility

A simple and efficient dual optical signaling chemodosimeter for toxic Hg(II)

• Sabir H. Mashraqui,
• Sapna A. Tripathi,
• Sushil S. Ghorpade and
• Smita R. Britto

Beilstein J. Org. Chem. 2012, 8, 1352–1357, doi:10.3762/bjoc.8.155

• ratiometric or switch-on responses even for the paramagnetic metal ions [17][18][19]. The first luminescence chemodosimeter for Hg2+ was developed by Czarnik et al. and was based on the Hg2+-mediated desulfurization of anthracene-thioamide chromophore [20][21]. Following this pioneering report, several other

• a quantum yield (ФF) of 0.021, calculated with respect to anthracene (ФF = 0.27) [61]. Fluorimetric titration (Figure 3) revealed linear enhancements in the emission intensity with a significant 17-fold enhancement observed at a limiting 5.1 × 10−5 M of Hg2+ [60]. Based on the linear response

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

• evidently increased. When anthracene was used as the reference, the fluorescence quantum yields of 1o–3o were determined to be 0.012, 0.018, and 0.059, respectively, indicating that the formyl group on the terminal benzene ring could notably enhance the fluorescence quantum yield and remarkably influence

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

Computational evidence for intramolecular hydrogen bonding and nonbonding X···O interactions in 2'-haloflavonols

• Tânia A. O. Fonseca,
• Matheus P. Freitas,
• Rodrigo A. Cormanich,
• Teodorico C. Ramalho,
• Cláudio F. Tormena and
• Roberto Rittner

Beilstein J. Org. Chem. 2012, 8, 112–117, doi:10.3762/bjoc.8.12

• more unusual stabilizing interactions are the nonbonding F···O interactions, which were experimentally and theoretically characterized in anthracene derivatives, and were pointed out to be the responsible interactions behind the unusual “through-space” fluorine–fluorine spin–spin coupling in the F···O

Functionalization of anthracene: A selective route to brominated 1,4-anthraquinones

• Kiymet Berkil Akar,
• Osman Cakmak,
• Orhan Büyükgüngör and
• Ertan Sahin

Beilstein J. Org. Chem. 2011, 7, 1036–1045, doi:10.3762/bjoc.7.118

• -dione (28). Therefore a selective and efficient method was developed for the preparation of compound 28 starting from 9,10-dibromoanthracene (1), in a simple four-step process. Compounds 10 and 11, and diol 27 constitute key precursors for the preparation of functionalized substituted anthracene

• derivatives that are difficult to prepare by other routes. The studies also reveal the broad range of reactivity and selectivity of the stereoisomeric anthracene derivatives. Keywords: anthracene derivatives; anthracene-1,4-dione; aromatization; bromination; bromoanthracene; methoxyanthracene; silver-induced

• hexabromides 2 and 3 (Scheme 1) [1]. These studies revealed that hexabromides 2 and 3 are good precursors for the preparation of anthracene oxides and methoxyanthracene derivatives by silver ion-induced substitution. Our previous studies revealed that aromatization of hexabromides 2 and 3 showed complete

Predicting the UV–vis spectra of oxazine dyes

• Scott Fleming,
• Andrew Mills and
• Tell Tuttle

Beilstein J. Org. Chem. 2011, 7, 432–441, doi:10.3762/bjoc.7.56

• illustrated in Figure 1 for clarity. All the dyes are based on an anthracene skeleton in which one carbon is replaced by a nitrogen atom and another by an additional heteroatom such as N, O, or S in the central ring. Although azine dyes have been found to demonstrate solvatochromism [1][2][3], and many

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

• to conceal the hydrophobic anthracene moiety inside the cavity with the carboxylate groups being exposed to the bulk water near the secondary rim of γ-CD. The enhanced chemical and optical yields observed for 3 should reflect the totally altered chiral environment, which favors the formation of one

Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37

• changes in excited-state reactivity, as has been shown for hydrogen bonded thiocarbonyl compounds in a theoretical study [51]. For comparison, it should be noted that the ISC rate constant of the thioureido-substituted anthracene 4 (Figure 3), kISC = 1.1 × 109 s−1 (CH3CN), even decreases by one order of

• magnitude upon association with acetate [27]. In that case, however, the absorption of the anthracene and the (trifluoromethyl)phenylthiourea part are well separated and the anthracene is excited selectively at lower energy. Moreover, as there is only one thioureido substituent attached to the anthracene in

• . Structures of chiral additives employed in DPM rearrangements. Structure of anthracene–thiourea conjugate 4. Proposed structure of the complex between 1h and mandelate SMD. Photorearrangements of dibenzobarrelenes 1a and 1b. Stereoselective DPM rearrangement of chiral salts in the solid-state. Synthesis of

Fluorometric recognition of both dihydrogen phosphate and iodide by a new flexible anthracene linked benzimidazolium-based receptor

• Kumaresh Ghosh and
• Debasis Kar

Beilstein J. Org. Chem. 2011, 7, 254–264, doi:10.3762/bjoc.7.34

• Kumaresh Ghosh Debasis Kar Department of Chemistry, University of Kalyani, Kalyani-741235, India 10.3762/bjoc.7.34 Abstract A new flexible anthracene linked benzimidazolium-based receptor 1 has been designed, synthesized and its binding properties have been studied by NMR, UV–vis and fluorescence

• emission of 1 gradually decreased without showing any other characteristic change in the spectra. Hydrogen bonding and charge–charge interactions interplay simultaneously in a cooperative manner for selectivity in the binding process. Keywords: anthracene coupled receptor; benzimidazolium-based receptor

• to afford the diamide 4 in 80% yield. Subsequent reaction of 4 with anthracene coupled benzimidazole 3 (prepared in 64% yield from benzimidazole and 9-chloromethylanthracene in the presence of NaH in dry THF) gave the dichloride salt 5 in 55% yield. Anion exchange using NH4PF6 in warm aqueous CH3OH

SbCl₃-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

• Ghasem Rezanejade Bardajee

Beilstein J. Org. Chem. 2011, 7, 135–144, doi:10.3762/bjoc.7.19

• ) which highlights the application of SbCl3 as useful catalyst in this methodology. Furthermore, the application range of the reaction was expanded to fused aromatic rings such as 9H-fluorene and anthracene: 9H-Fluorene-2-carbaldehyde and anthracene-9-carbaldehyde react with N,N-dimethylaniline under the

An easy assembled fluorescent sensor for dicarboxylates and acidic amino acids

• Xiao-bo Zhou,
• Yuk-Wang Yip,
• Wing-Hong Chan and
• Albert W. M. Lee

Beilstein J. Org. Chem. 2011, 7, 75–81, doi:10.3762/bjoc.7.11

• ) became magnetically non-equivalent. At the same time, the Ha, Hb and Hd protons of the host experienced an upfield shift of ~0.07 ppm, whereas the Hc protons were downfield shifted by 0.19 ppm. Conceivably, as a result of complexation, the spatial relationship between the mesitylene and the anthracene

Anthracene appended pyridinium amide–urea conjugate in selective fluorometric sensing of L-N-acetylvaline salt

• Kumaresh Ghosh,
• Tanmay Sarkar and
• Asoke P. Chattopadhyay

Beilstein J. Org. Chem. 2010, 6, 1211–1218, doi:10.3762/bjoc.6.139

• Kumaresh Ghosh Tanmay Sarkar Asoke P. Chattopadhyay Department of Chemistry, University of Kalyani, Kalyani-741235, India, Fax +91-33-25828282 10.3762/bjoc.6.139 Abstract A new anthracene labeled pyridinium amide–urea conjugate 1 has been designed and synthesized. The receptor shows a different

• to the charge–charge interaction and formation of unconventional hydrogen bonds with the anionic guests [27]. In order to explore this binding site for a wide range of substrates, especially for amino acid derivatives, we report here the design and synthesis of a new fluororeceptor 1 where anthracene

• -N-acetylvaline salt than with L-N-acetylalanine. This is attributed to the formation of a charge transfer complex between the excited state of anthracene and the electron deficient nitrophenyl urea during the interaction process. We believe that this characteristic feature with L-N-acetylvaline is

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

• Bernd Tieke,
• A. Raman Rabindranath,
• Kai Zhang and
• Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

• ]. The polymers consisted of dialkylated DPP units and carbazole, triphenylamine, benzo[2,1,3]thiadiazole, anthracene, or fluorene units in alternating fashion. They were prepared via Suzuki coupling, from the DPP monomers M-1 or DPP-3,6-diphenyl(4,4´-bis(pinacolato)boron ester. A number of readily

• 39 nm. The small shift of P-2 was ascribed to a large tilt angle between the π-planes of DPP and the adjacent comonomer units, in this case the anthracene unit, which strongly reduces the conjugation length [32]. EL devices prepared with P-4 exhibited an external quantum efficiency (EQE) of 0.5% and

Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines

• Adam W. Franz,
• Svetlana Stoycheva,
• Michael Himmelhaus and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2010, 6, No. 72, doi:10.3762/bjoc.6.72

• with the surface normal, and lAu–S = 2.1 Å is the Au–S bond length [57]. For φ, we refer to a recent electron spectroscopic analysis on similar aromatic systems, which determined φ = 23° for anthracene-2-thiol [58]. Using this value, we made the reasonable assumption that the Au–S–C bond is mainly

Anthracene functionalized terpyridines – synthesis and properties

• Falk Wehmeier and
• Jochen Mattay

Beilstein J. Org. Chem. 2010, 6, No. 54, doi:10.3762/bjoc.6.54

• (terpyridine)complexes 6a–b. Irradiation experiments were carried out with both the free ligands and an iron(II)-complex in order to investigate the photochemistry of the compounds. Keywords: anthracene; coordination chemistry; photochemistry; terpyridine; Introduction 2,2′:6′,2″-Terpyridines have been of

• diarylethenes [10][11]. There have also been reports about anthracene functionalized terpyridines in which an anthracene unit was used as a fluorescent sensor [12], spacer [13] or intercalator [14]. Herein we report the synthesis of two twofold anthracene functionalized terpyridines, their iron(II) complexes

• , and investigations regarding their photochemistry. Results and Discussion Synthesis of anthracene functionalized terpyridines We synthesized the terpyridine-4,4″-diacid 3, starting from methyl 2-acetylisonicotinate (1) and 4-tert-butylbenzaldehyde (2), by a one-pot combination of a Kröhnke type