- N,N'-Diphenyl-1,4(5)-dimethoxyanthraquinone Diimines: "Butterfly" Inversion of Anthraquinone Diimines
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Model compounds for polyaromatic quinone imines were synthesized and characterized by variable-temperature 1H NMR spectroscopy and X-ray single crystal structure determination.N,N'-Diphenyl-1,4(5)-dimethoxyanthraquinone 9,10-diimines were synthesized by condensing 2 equiv of aniline with 1,5-dimethoxyanthraquinone (15DMAQ) and 1,4-dimethoxyanthraquinone (14DMAQ), respectively, in the presence of titanium tetrachloride and 1,4-diazabicyclooctane (DABCO).The X-ray single crystal structure determination of the diimine of 15DMAQ is reported.The condensation of aniline with anthraquinones results in a buckling of the anthraquinone ring system, giving it a "butterfly" conformation while the diimine of 15DMAQ has an anti configuration with the N-phenyl rings lying above the methoxy substituents.The diimine of 14DMAQ has a syn configuration, again with these N-phenyl rings lying above the methoxy substituents.The symmetrical structural butterfly conformations of the diimines allowed for the observation of a dynamic butterfly inversion by variable-temperature 1H NMR spectroscopy.The energy barriers for the butterfly inversion of N-phenyl 15DMAQ and 14DMAQ diimines are 9.5 kcal/mol.The implications of the crystal structure and molecular dynamics for the polymeric structures are discussed.
- Boone, Harold W.,Bruck, Michael A.,Bates, Robert B.,Padias, Anne Buyle,Hall, H. K.
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- 1,4-Dipole-Metalated Quinone Strategy to (+/-)-4-Demethoxydaunomycinone and (+/-)-Daunomycine. Annelation of Benzocyclobutenedione Monoketals with Lithioquinone Bisketals
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A strategy for total synthesis of anthracyclinones is outlined in which a benzocyclobutenedione monoketal, serving as a 1,4-dipole equivalent, is reacted with a lithiated quinone bisketal, serving as a metalated quinone equivalent, to afford in one step a fully functionalized tetracyclic ring system.A convenient synthesis of the AB-ring system with the eventual C7 and C9 oxygen functions of the anthracyclinone present has been developed.In addition, a trimethylsilyl-mediated benzylic bromination serves as one of the key steps in a novel methylene-to-carbonyl transformation, resulting in a regiospecific route to benzocyclobutenedione monoketals.The potential general synthetic utility arising from trimethylsilyl-stabilized radical intermediates is noted.The chemistry described above resulted in a convergent, regiospecific route to (+/-)-4-demethoxydaunomycinone and (+/-)-daunomycinone
- Swenton, John S.,Anderson, D. Keith,Jackson, Daniel K.,Narasimhan, Lakshmi
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- Evaluation of a series of 9,10-anthraquinones as antiplasmodial agents
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Background: A phytochemical study on medicinal plants used for the treatment of fever and malaria in Africa yielded metabolites with potential antiplasmodial activity, many of which are Anthraquinones (AQ). AQs have similar sub-structure as naphthoquinones and xanthones, which were previously reported as novel antiplasmodial agents. Objective: The present study aimed to investigate the structural requirements of 9,10-anthraquinones with hydroxy, methoxy and methyl substituents to exert strong antiplasmodial activity and to investigate their possible mode of action. Methods: Thirty-one AQs were synthesized through Friedel-Crafts reaction and assayed for antiplasmodial activity in vitro against Plasmodium falciparum (3D7). The selected compounds were tested for toxicity and probed for their mode of action against β-hematin dimerization through HRP2 and lipid catalyses. The most active compounds were subjected to a docking study using AutoDock 4.2. Results: The active AQs have similar common structural characteristics. However, it is difficult to establish a structure-activity relationship as certain compounds are active despite the absence of the structural features exhibited by other active AQs. They have either ortho- or meta-arranged substituents and one free hydroxyl and/or carbonyl groups. When C-6 is substituted with a methyl group, the activity of AQs generally increased. 1,3-DihydroxyAQ (15) showed good antiplasmodial activity with an IC50 value of 1.08 μM, and when C-6 was substituted with a methyl group, 1,3-dihydroxy-6-methylAQ (24) showed stronger antiplasmodial activity with an IC50 value of 0.02μM, with better selectivity index. Compounds 15 and 24 showed strong HRP2 activity and mild toxicity against hepatocyte cells. Molecular docking studies showed that the hydroxyl groups at the ortho (23) and meta (24) positions are able to form hydrogen bonds with heme, of 3.49 A and 3.02 A, respectively. Conclusion: The activity of 1,3-dihydroxy-6-methylAQ (24) could be due to their inhibition against the free heme dimerization by inhibiting the HRP2 protein. It was further observed that the anthraquinone moiety of compound 24 bind in parallel to the heme ring through hydrophobic interactions, thus preventing crystallization of heme into hemozoin.
- Osman, Che Puteh,Ismail, Nor Hadiani,Widyawaruyanti, Aty,Imran, Syahrul,Tumewu, Lidya,Choo, Chee Yan,Ideris, Sharinah
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p. 353 - 363
(2019/06/20)
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- Clip[5]arenes: A new family of molecular clips
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Here we report the design and syntheses of two new triptycene-based rigid acyclic C-shaped hosts, clip[5]arenes C[5]OH and C[5]ME, and the strong host–guest complexation between C[5]OH and an electron-poor bipyridinium salt, paraquat G. The Ka value for the host–guest complex C[5]OH ? G was calculated to be (1.09 ± 0.36) × 105 M?1 in acetone by using a non-linear curve-fitting method based on the UV–vis absorption titration experiments. Furthermore, based on this new host–guest recognition motif, a novel pseudopolyrotaxane-like supramolecular structure was constructed with C[5]OH threaded on polyviologen polymer VP-10.
- Shi, Bingbing,Li, Zhengtao,Liu, Yuezhou,Shangguan, Liqing,Zhu, Huangtianzhi,Ju, Huaqiang,Huang, Feihe
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supporting information
p. 3477 - 3480
(2018/08/22)
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- Synthesis method of anthraquinone derivatives and tetracenedione derivatives through benzannulation reaction
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The present invention relates to a method for synthesizing anthraquinone derivatives and tetracene dione derivatives through a benzannulation reaction, which presents a novel synthesis method, capable of processing synthesis easily, conveniently, and efficiently under mild conditions by an organic catalyst. The synthesis method uses an L-proline catalyst which is nontoxic, economical and easily available, compared to conventional production methods, thereby providing the anthraquinone derivatives and the tetracene dione derivatives through the one-pot benzannulation reaction of an α, β-unsaturated aldehyde compound, various 1,4-naphthoquinone compounds or 1,4-anthracenedione compounds. Various forms of anthraquinone derivatives or tetracene dione derivatives prepared by the synthesis method can be widely used for synthesis of natural products, dyes, and pharmaceutical products.COPYRIGHT KIPO 2017
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Paragraph 0029-0030; 0045
(2017/08/09)
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- Access to 1,2,3,4-Tetraoxygenated Benzenes via a Double Baeyer-Villiger Reaction of Quinizarin Dimethyl Ether: Application to the Synthesis of Bioactive Natural Products from Antrodia camphorata
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The first systematic investigation into the Baeyer-Villiger reaction of an anthraquinone is presented. The double Baeyer-Villiger reaction of quinizarin dimethyl ether is viable, directly providing the dibenzo[b,f][1,4]-dioxocin-6,11-dione ring-system, which is otherwise difficult to prepare. This methodology provides rapid access to 1,2,3,4-tetraoxygenated benzenes, and has been exploited by application to the total synthesis of a natural occurring benzodioxole and its biphenyl dimer, which both display noteworthy biological activity. Interestingly, the axially chiral biphenyl was found to be configurationally stable, but the resolved enantiomers exhibit no optical activity at the αD-line.
- Newson, Harriet L.,Wild, Duncan A.,Yeung, Sing Yee,Skelton, Brian W.,Flematti, Gavin R.,Allan, Jane E.,Piggott, Matthew J.
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p. 3127 - 3135
(2016/05/19)
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- Organocatalyzed benzannulation for the construction of diverse anthraquinones and tetracenediones
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An efficient one-pot synthesis of anthraquinones and tetracenediones was achieved vial-proline catalyzed [4+2] cycloaddition of in situ generated azadiene from α,β-unsaturated aldehydes and 1,4-naphthoquinones or 1,4-anthracenedione in good to excellent yield. This protocol constitutes an unprecedented tandem benzannulation that allows one-pot construction of diverse anthraquinones and tetracenediones in the presence of organocatalysts. This methodology was applied successfully to the synthesis of naturally occurring molecules and photochemically interesting phenanthrenequinone derivatives.
- Somai Magar, Krishna Bahadur,Xia, Likai,Lee, Yong Rok
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supporting information
p. 8592 - 8595
(2015/05/20)
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- Synthesis of new cytotoxic aminoanthraquinone derivatives via nucleophilic substitution reactions
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Aminoanthraquinones were successfully synthesized via two reaction steps. 1,4-Dihydroxyanthraquinone (1) was first subjected to methylation, reduction and acylation to give an excellent yield of anthracene-1,4-dione (3), 1,4-dimethoxyanthracene- 9,10-dione (5) and 9,10-dioxo-9,10-dihydroanthracene-1, 4-diyl diacetate (7). Treatment of 1, 3, 5 and 7 with BuNH2 in the presence of PhI(OAc)2 as catalyst produced seven aminoanthraquinone derivatives 1a, b, 3a, and 5a-d. Amination of 3 and 5 afforded three new aminoanthraquinones, namely 2-(butylamino)anthracene-1,4-dione (3a), 2-(butylamino)anthracene-9,10-dione (5a) and 2,3-(dibutylamino)anthracene-9,10-dione (5b). All newly synthesised aminoanthraquinones were examined for their cytotoxic activity against MCF-7 (estrogen receptor positive human breast) and Hep-G2 (human hepatocellular liver carcinoma) cancer cells using MTT assay. Aminoanthraquinones 3a, 5a and 5b exhibited strong cytotoxicity towards both cancer cell lines (IC50 1.1-13.0 μg/mL).
- Nor, Siti Mariam Mohd,Sukari, Mohd Aspollah Hj Md,Azziz, Saripah Salbiah Syed Abdul,Fah, Wong Chee,Alimon, Hasimah,Juhan, Siti Fadilah
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p. 8046 - 8062
(2013/08/23)
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- Synthesis of 1,4-Anthracene-9,10-dione derivatives and their regulation of nitric oxide, IL-1β and TNF-α in activated RAW264.7 cells
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Mitoxantrone is an anthracenedione antineoplastic and immunosuppressive agent approved for multiple sclerosis treatment. Novel mono- and disubstituted anthraquinone derivatives, analogues of mitoxantrone, were synthesized through the addition of lipophilic amino alcohols and evaluated for their effect on IL-1β, TNF-α and nitric oxide production by LPS/IFN-γ-stimulated RAW264.7 cells. The disubstituted 1,4-anthracene-9,10-dione 10 showed significant inhibition of nitric oxide, TNF-α and IL-1β production at the concentration of 5 μg/mL, with a much lower cytotoxicity than mitoxantrone. The monosubstituted 3, 4, 11, 12 and 13 also displayed a moderate to good inhibitory capacity on IL-1β production. However, the methylated compounds 11, 12 and 13 failed to inhibit the TNF-α production, and compound 13 was the only one to decrease the production of nitric oxide. None of these derivatives was toxic at the tested concentrations. Compounds 10 and 13 had better inhibitory capacity of the inflammatory mediators analyzed, with reliable viability of the cells.
- Correa, Tais Arthur,Alves, Caio C. S.,Castro, Sandra B. R.,Oliveira, Erick E.,Franco, Lucas S.,Ferreira, Ana P.,De Almeida, Mauro V.
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p. 463 - 467
(2013/10/08)
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- Synthesis of damnacanthal, a naturally occurring 9,10-anthraquinone and its analogues, and its biological evaluation against five cancer cell lines
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Damnacanthal and nordamnacanthal, two naturally occurring 9,10-anthraquinones, and their analogues were synthesized. Cytotoxic activity against five cancer cell lines was evaluated using MTT assay. 2-Bromomethyl-1,3-dimethoxyanthraquinone was found to display the highest activity against all cell lines with IC50 range of 2-8 μM. Structure-activity relationship (SAR) assessment was considered to rationalise the cytotoxic effect. Bromomethyl group at position C-2 of the anthraquinone was found to be important in exerting cytotoxic activity of this class of compounds. The presence of the flanking methoxyl or hydroxyl groups at C-1 and C-3 also contributes to this activity. Finally, the antioxidant effect of these compounds was evaluated. MTT assay was used to measure the cytotoxicity against different cancer cell lines. Antioxidant activity was measured by FTC and TBA methods. Only two anthraquinones, damnacanthal and nordamnacanthal, were found to be antioxidative.
- Saha, Koushik,Lam, Kok Wai,Abas, Faridah,Sazali Hamzah,Stanslas, Johnson,Hui, Lim Siang,Lajis, Nordin H.
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p. 2093 - 2104
(2013/07/26)
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- Synthesis, isolation, and characterization of Diels-Alder adducts between 1,4-dialkoxyanthracenes and maleic anhydride
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In the Diels-Alder reaction of 1,4-dialkoxyanthracenes and maleic anhydride, which can afford syn- and anti-cycloadducts, the bridgehead methine proton of the cycloadducts has proved to be a useful probe for determining syn/anti selectivity, as supported by isolation of diastereomers, 1H NMR spectroscopy, and X-ray analysis. In the case of methoxy and propoxy substituents, a slight anti-preference was observed, on the other hand, the reaction of 1,4-bis(benzyloxy)anthracene gave a small syn-preference. Theoretical calculations of transition states of 1,4-dimethoxyanthracene and maleic anhydride showed no stereochemical preference. From UV-vis spectra, the formation of charge transfer complexes of anthracenes and maleic anhydride is possible.
- Kitamura, Chitoshi,Hasegawa, Munehiro,Ishikawa, Hiroshi,Fujimoto, Jun,Ouchi, Mikio,Yoneda, Akio
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p. 1385 - 1393
(2007/10/03)
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- A New Convenient Synthesis of Alkoxyanthracenes from Alkoxy-9,10- anthraquinones
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Methoxy-9,10-anthraquinones with mono-, di- and tetraether groups at different positions 1a-h can be directly reduced to the corresponding methoxyanthracenes 3a-h in moderate to good yields by zinc in refluxing acetic acid. Under similar conditions, ethyl 1′-anthracenoxyacetate (3i) with the ester group unaffected and 1,8-oxybis(ethyleneoxyethyleneoxy)anthracene (5) were also conveniently synthesized in 65 and 70% yields, respectively.
- Lu, Lingang,Chen, Qiyin,Zhu, Xiaozhang,Chen, Chuanfeng
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p. 2464 - 2466
(2007/10/03)
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- Total synthesis of (-)-balanol
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The efficient total synthesis of (-)-balanol, a potent inhibitor of the protein kinase C, is described (-)-Balanol consists of a chiral hexahydroazepine-containing fragment and a benzophenone fragment, both of which were prepared via novel synthetic routes. The hxahydroazepine fragment was prepared in racemic form through either Bu3SnH- or SmI2-promoted radical cyclization of oxime ethers 2ab intramolecularly connected with the formyl group. SmI2-promoted radical cyclization of 2b was found to be particularly successful in the selective synthesis of the seven-membered trans-amino alcohol 8b. Preparation of the enantiomerically pure hexahydroazepine-containing fragment was achieved through the enantioselective enzymatic acetylation of racemic alcohol 9, employing the immobilized lipase from Pseudomonas sp. The benzophenone fragment was prepared in short steps through a biomimetic oxidative anthraquinone ring cleavage starting from commercially available natural chrysophanic acid 15c. This reaction proceeded via [4 + 2]-cycloaddition of single of oxygen to anthracene derivative 17c, followed by Baeyer-Villiger-type rearrangement of the resulting hydroperoxide to afford the benzophenone derivatives 22 and 23.
- Miyabe, Hideto,Torieda, Mayumi,Inoue, Kyoko,Tajiri, Kazumi,Kiguchi, Toshiko,Naito, Takeaki
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p. 4397 - 4407
(2007/10/03)
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- BeCl2 as a new highly selective reagent for dealkylation of aryl-methyl ethers
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An efficient and simple method is introduced for the selective removal of methyl group from poly aryl-methyl ethers, in some important derivatives of benzophenones, xanthones, anthraquinones, aryl esters, benzamides and nitroanisoles with BeCl2.
- Sharghi, Hashem,Tamaddon, Fatemeh
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p. 13623 - 13640
(2007/10/03)
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- Experiments Directed Towards the Synthesis of Anthracyclinones. XIX. Elaboration of 2-Formylquinizarin Through a Wittig Reaction
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Reaction of 2-formylquinizarin dimethyl ether (3) with the dimethoxy ylide (6) gives an α,β-unsaturated ester (8) which on hydrogenation, reduction and methylation gives the tetramethoxyanthracene diester (18).When linked to work by Doetz and Popall this
- Boniface, Peter J.,Cambie, Richard C.,Carroll, David R.,Marsh, Nicholas F.,Milbank, Jared B. J.,et al.
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p. 441 - 450
(2007/10/02)
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- Total synthesis of (+)-4-demethoxydaunomycin
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Starting from commercially available dyestuff intermediate, quinizarin (6) as BCD-ring synthon for anthracycline, a key intermediate 5b has been prepared by a simple reaction sequence. (+/-)-4-Demethoxydaunomycinone (4b) has been synthesized from 5b.Further 4b was coupled with L-daunosamine derivative (24) to give the requisite α-glycoside 4a.
- Ayyangar, N R,Argade, A B,Mehendale, A R,Deshpande, V H
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p. 377 - 384
(2007/10/02)
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- Preparation of Anthraquinones from 10-Hydroxy-9-anthracenecarbonitriles Obtained from a Novel Aryne Annulation Reaction
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A new method for brief regioselective synthesis of anthraquinones via the reaction of anions of ethyl cyanoacetate or the anions of 2-(carbethoxyaryl)acetonitriles with arynes is described.
- Bhawal, Baburao M.,Khanapure, Subhash P.,Zhang, Hongming,Biehl, Edward R.
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p. 2846 - 2849
(2007/10/02)
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- Obtention of anthraquinones by selective oxidation of the corresponding anthracenes and 9,10-dimethoxyanthracenes with copper or zinc nitrate supported on silica gel
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Anthracene, 9,10-dimethoxyanthracene and substituted analogues are selectively oxidized to the corresponding anthraquinones in good yields by copper(II) or zinc(II) nitrate supported on silica gel; the ether groups at different position from 9 and 10 are unaffected.
- Anastasia,Allevi,Bettini,Fiecchi,Sanvito
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p. 1083 - 1084
(2007/10/02)
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- Nitrodienamines: An Easy Synthesis and Cycloaddition Reactions with α,β-Unsaturated Carbonyl Compounds and Quinones
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The nitrodienamine 6 was synthesized through the vinamidinium salt 7.The reactivity of 6 was investigated with the α,β-unsaturated carbonyls and styrene 8-14, and the quinones 15, 16, 25, 29, 31, 33, 37, and 41.Keywords: nitrodienamine; synthesis; cycloaddition; α,β-unsaturated carbonyl; quinone; vinamidinium salt
- Takeuchi, Naoki,Ohki, Junji,Tobinaga, Seisho
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p. 481 - 487
(2007/10/02)
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- ESR Spectroscopic Detection of Intramolecular Interactions in Radical Cations of Poly(α-methoxy)triptycenes
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-Cycloaddition of 1,4-benzoquinone to the di- and tetra(α-methoxy)anthracenes 11 yields the diketones 12 which undergo an acid-catalyzed rearrangement to the triptycene hydroquinones 13.Methylation of 13 affords the poly(α-methoxy)triptycenes 4.Aluminium chloride in nitromethane oxidizes the triptycenes 4 to the radical cations 4+* having one 1,4-dialkoxybenzene ring (4b+*, 4c+*, 4e+*) or two (4a+*) or three (4d+*), respectively, of such potential radical centers.The protons of the radical center give rise to hyperfine splittings which are very similar to those found in the ESR spectra of simple cis-1,4-dialkoxybenzene radical cations.The other aromatic protons, but not the bridgehead protons, exhibit a long range hyperfine coupling of 0.011 mT.Selective line broadening in the ESR spectrum of the radical cation 4a+* indicates that intramolecular electron transfer between the 1,4-dimethoxybenzene moieties occurs at a moderate rate.The deceleration of the exchange rate compared to the rate expected for a free radical cation is interpreted in terms of ion pairing.
- Quast, Helmut,Fuchsbauer, Hans-Lothar
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p. 1016 - 1038
(2007/10/02)
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- Mechanistic Aspects of the Annelation Reactions of Benzocyclobutenedione Monoketals with Vinyllithium Reagents
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The mechanism of the annelation reaction of vinyllithium reagents with benzocyclobutenedione monoketals has been investigated.The results of these studies strongly support a mechanism involving addition of the organolithium reagent to form the lithium salt of a benzocyclobutenol followed by ring opening and cyclization to produce the tricyclic product.This reaction was examined with benzocyclobutenone and with the ethylene glycol and ethanedithiol monoketals of benzocyclobutenedione as the carbonyl components.The lithio derivatives of the bisketal of 2-bromobenzoquinone, the ethylene glycol ketal of α-bromocyclohexenone, and the ethanedithiol ketal of β-bromocyclohexenone were explored as the organometallic components.These studies have established the major mechanistic aspects and the scope of this annelation reaction.
- Spangler, Lori A.,Swenton, John S.
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p. 1800 - 1806
(2007/10/02)
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- Selective Dealkylation of Methoxyanthraquinones via Difluoro1,O9>boron Chelates: Synthesis of Hydroxymethoxyanthraquinones
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1,8-, 1,5- 1,2-, and 1,4-Dimethoxyanthraquinones have been treated with boron trifluoride-diethyl ether to give difluoro(anthraquinonato)boron chelates (1a-d) respectively. 1,4,5-Trimethoxyanthraquinone was similarly converted separately in benzene and toluene into the mono- (2) and bis-difluoroboron(3)-chelates respectively, and 2,2',4,4'-tetramethoxybenzophenone was converted by BF3*Et2O in toluene into the boron adduct (4).Treatment of these derivatives, (1a-d) and (2)-(4), with methanol gave the following uncomplexed derivatives in good yield respectively: 1-hydroxy-8-methoxyanthraquinone, 1-hydroxy-5-methoxyanthraquinone, 1-hydroxy-2-methoxyanthraquinone, 1-hydroxy-4-methoxyanthraquinone, 4-hydroxy-1,5-dimethoxyanthraquinone, 1,4-dihydroxy-5-methoxyanthraquinone, and 2-hydroxy-2',4,4'-trimethoxybenzophenone.
- Preston, Peter N.,Winwick, Thomas,Morley, John O.
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p. 1439 - 1441
(2007/10/02)
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- Selective Demethylation of Di- and Tri-methoxyanthraquinones via Aryloxydifluoroboron Chelates. Synthesis of 4-Hydroxy-1,5-dimethoxyanthraquinone and 1,4-Dihydroxy-5-methoxyanthraquinone
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Methoxyanthraquinone derivatives react with boron trifluoride-diethyl ether to give mono- and bis-difluoroboron chelates which, in methanol, are converted into hydroxyanthraquinones; an extension of this method is described for the synthesis of 2-hydroxy-2',4,4'-trimethoxybenzophenone.
- Preston, Peter N.,Winwick, Thomas,Morley, John O.
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- Regiospecific Synthesis of Quinizarin and Naphthazarin Derivatives by Cycloaddition
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The diene (E)-1,1,4-trimethoxybuta-1,3-diene underwent regiospecific cycloaddition to derivatives of 2(3)-chloro-1,4-naphthoquinone.The resulting adducts were aromatized to give 1,4-dioxygenated anthraquinones.The latter were obtained as derivatives of quinizarin dimethyl ether or of quinizarin monomethyl ether depending on the conditions of aromatization.Cycloaddition of the diene to non-halogenated naphthoquinones proceeded similarly, orientation being controlled by substituents in the benzenoid ring.Analogous reaction of the diene with benzoquinones gave 5,8-dioxygenated naphthoquinones (naphthazarins), generally in limited yield.The procedure has been applied to synthesis of the mould metabolites helminthosporin and cynodontin
- Cameron, Donald W.,Feutrill, Geoffrey I.,McKay, Peter G.
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p. 2095 - 2109
(2007/10/02)
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- REGIOSPECIFIC SYNTHESIS OF QUINIZARIN DERIVATIVES BY CYCLOADDITION
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Cycloaddition of (E)-1,1,4-trimethoxy-1,3-butadiene (1) to naphthoquinones affords regiospecific syntheses of derivatives of 1,4-dihydroxyanthraquinone including the mould metabolites helminthosporin (21) and cynodontin (22).
- Cameron, Donald W.,Feutrill, Geoffrey I.,McKay, Peter G.
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p. 701 - 702
(2007/10/02)
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- Synthesis and Evaluation of Fluorescent Materials for Colour Control of Peroxyoxalate Chemiluminescence. III. Yellow and Red Fluorescent Emitters
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A number of bis(phenylethynyl)-substituted anthracenes and naphthacenes have been synthesized and their suitability as fluorescent additives for peroxyoxalate chemiluminescence evaluated.Fluorescence and chemiluminescence emission data for all compounds are presented.Both 2-chloro- and 6-chloro-5,12-bis(phenylethynyl)naphthacene provide effective scarlet chemiluminescence with the peroxyoxalate system (λmax 609 and 614 nm respectively).Althgough solutions of both compounds decolorize slowly in the presence of air and light, when used in concentrations 0f 1-5*10-3 M they allow efficient chemiluminescence for greater than 5 h.
- Hanhela, Peter J.,Paul, Brenton D.
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p. 1701 - 1717
(2007/10/02)
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- A New Route to Anthraquinones
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The lithium salts derived from position 3 of phthalides react with arynes to form adducts, which, upon aerial oxidation, produce anthraquinones in moderate to good yields.Substituted phthalides and arynes also participate in this general reaction.The addition to unsymmetrically substituted arynes shows regioselectivity, whilst the availability of a new general route to phthalides extends the scope of this reaction.
- Dodsworth, David J.,Calcagno, Maria-Pia,Ehrmann, E. Ursula,Devadas, Bhatt,Sammes, Peter G.
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p. 2120 - 2124
(2007/10/02)
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