- Stereoselective approach to the dihydroagarofuran framework via directed intramolecular radical addition
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The radical derived from bromoacetal 12 undergoes intramolecular addition to give predominantly the cyclic acetal 13 in which the C12 methyl substituent is endo.
- White, James D.,Shin, Hyunik
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Read Online
- Bimetallic copper/cobalt-cocatalyzed double aerobic phenol oxidation/cyclization toward π-extended benzofuro[2,3-b]indoles as electron donors for electroluminescence
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Benzofuro[2,3-b]indoles, apart from their attractive biological features, constitute a novel family of electron donors for electroluminescent materials. Reported herein is the establishment of a strategy involving bimetallic catalysis to form such π-conju
- Bashir, Muhammad Adnan,Zhang, Yulong,Yu, Huaibin,Wang, Bofei,Zhao, Weining,Zhong, Fangrui
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p. 5031 - 5036
(2021/07/29)
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- Dehydrogenation/(3+2) Cycloaddition of Saturated Aza-Heterocycles via Merging Organic Photoredox and Lewis Acid Catalysis
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Herein, we report a photoinduced dehydrogenation/(3+2) cycloaddition reaction by merging organic photoredox and Lewis acid catalysis, providing a straightforward and efficient approach for directly installing a benzofuran skeleton on the saturated aza-heterocycles. In this protocol, we also describe a novel organic photocatalyst (t-Bu-DCQ) with the advantages of a wider redox potential, easy synthesis, and a low price. Furthermore, the stepwise activation mechanism of dual C(sp3)-H bonds was demonstrated by a series of experimental and computational studies.
- Xiao, Teng-Fei,Zhang, Yi-Fan,Hou, Wen-Tao,Yan, Pen-Ji,Hai, Jun,Xu, Peng-Fei,Xu, Guo-Qiang
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supporting information
p. 8942 - 8946
(2021/11/24)
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- Peptide-Catalyzed Fragment Couplings that Form Axially Chiral Non-C2-Symmetric Biaryls
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We have demonstrated that small, modular, tetrameric peptides featuring the Lewis-basic residue β-dimethylaminoalanine (Dmaa) are capable of atroposelectively coupling naphthols and ester-bearing quinones to yield non-C2-symmetric BINOL-type scaffolds with good yields and enantioselectivity. The study culminates in the asymmetric synthesis of backbone-substituted scaffolds similar to 3,3′-disubstituted BINOLs, such as (R)-TRIP, with good (94:6 e.r.) to excellent (>99.9:0.1 e.r.) enantioselectivity after recrystallization, and a diastereoselective net arylation of the minimally modified nonsteroidal anti-inflammatory drug (NSAID) naproxen.
- Coombs, Gavin,Sak, Marcus H.,Miller, Scott J.
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supporting information
p. 2875 - 2880
(2020/01/24)
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- Catalytic asymmetric synthesis of aryl diphenol the axis chiral is joint method
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The invention discloses a method for catalyzing asymmetrically synthesized axially chiral biaryl diphenol. In an organic solvent, chiral phosphoric acid is taken as a catalyst, a compound shown in a formula III is obtained by reaction on a compound shown
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Paragraph 0049; 0050; 0051
(2017/10/31)
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- Design and Discovery of Functionally Selective Serotonin 2C (5-HT2C) Receptor Agonists
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On the basis of the structural similarity of our previous 5-HT2C agonists with the melatonin receptor agonist tasimelteon and the putative biological cross-talk between serotonergic and melatonergic systems, a series of new (2,3-dihydro)benzofu
- Cheng, Jianjun,McCorvy, John D.,Giguere, Patrick M.,Zhu, Hu,Kenakin, Terry,Roth, Bryan L.,Kozikowski, Alan P.
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supporting information
p. 9866 - 9880
(2016/11/19)
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- USE OF SUBSTITUTED 2,3-DIHYDRO-1-BENZOFURAN-4-CARBOXYLIC ACIDS OR SALTS THEREOF AS ACTIVE SUBSTANCES AGAINST ABIOTIC PLANT STRESS
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Use of substituted 2,3-dihydro-1-benzofuran-4-carboxylic acids of the general formula (I) or salts thereof where the radicals in the general formula (I) are as defined in the description, for increasing stress tolerance in plants with respect to abiotic
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Paragraph 0142
(2015/12/11)
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- Atroposelective Synthesis of Axially Chiral Biaryldiols via Organocatalytic Arylation of 2-Naphthols
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The first phosphoric acid-catalyzed asymmetric direct arylative reactions of 2-naphthols with quinone derivatives have been developed, providing efficient access to a class of axially chiral biaryldiols in good yields with excellent enantioselectivities u
- Chen, Ye-Hui,Cheng, Dao-Juan,Zhang, Jian,Wang, Yong,Liu, Xin-Yuan,Tan, Bin
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supporting information
p. 15062 - 15065
(2015/12/18)
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- Cobalt-catalyzed arylation and alkenylation of alpha-bromo eneformamides and enecarbamates by cross-coupling with organic bromides: Application to the synthesis of functionalized piperidines and azepanes
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The synthesis of α-arylated and alkenylated piperidine and azepane derivatives has been accomplished through cross-coupling of α-bromo eneformamides or enecarbamates with feedstock organic halides such as aryl and vinyl bromides, under cobalt catalysis. The coupling products, which themselves are synthetic intermediates for accessing other functionalized piperidines and azepanes are obtained in good to excellent yields.
- Bassler, Daniel P.,Alwali, Amir,Spence, Laura,Beale, Oliver,Beng, Timothy K.
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supporting information
p. 6 - 12
(2015/01/30)
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- Experimental and Theoretical Justification for the Regiospecific Cycloaddition of Levopimaric Acid to 2-Acetyl- or 2-(Methoxycarbonyl)-1,4-Benzoquinone
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New 4a-quinopimaric acid derivatives were synthesized via a Diels-Alder reaction of levopimaric acid with 2-acetyl- or 2-(methoxycarbonyl)-1,4-benzoquinone and were characterized using elemental analysis and NMR spectroscopy. Thermodynamic and activation
- Vafina,Borisevich,Uzbekov,Poptsov,Spirikhin,Khursan
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p. 1120 - 1125
(2016/02/18)
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- Synthesis and X-ray crystal structure of cynandione B analogues
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The synthesis of analogues of cynandione B, a phenolic acetophenone from Cynanchum taiwanianum, is described. The one-step conversion of benzochromenones to the heptacyclic spiroacetal core of cynandione B using methylmagnesium bromide is investigated and
- Hong, Lisa P. T.,White, Jonathan M.,Donner, Christopher D.
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scheme or table
p. 58 - 64
(2012/07/28)
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- Correction of a reported xanthone synthesis: The preparation of a Benzo[c]coumarin
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Reinvestigation of a reported synthesis of 5,8-dihydroxy-1,3- dimethoxyxanthone from the reaction of 3,5-dimethoxyphenol with 2-(methoxycarbonyl)-1,4-benzoquinone resulted in the identification of the product as the isomer of benzo[c]coumarin, i.e., 7,10-
- Benn, Michael H.,Parvez, Masood,Perry, Nigel B.,Rauka, Arvi,Van Klink, John W.
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experimental part
p. 389 - 394
(2010/05/19)
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- Eight-step synthesis of routiennocin
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Routiennocin is a member of a family of polycyclic pyrrole ether antibiotics that simultaneously uncouple oxidative phosphorylation and inhibit ATPase as a result of selective complexation of divalent metal ions. We describe a concise synthesis of routien
- Matsumotoa, Kenji,Kozmina, Sergey A.
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supporting information; experimental part
p. 557 - 560
(2009/04/11)
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- Aerobic oxidation of hydroquinone derivatives catalyzed by polymer-incarcerated platinum catalyst
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(Chemical Equation Presented) It's a lock-in! A remarkably wide substrate scope of hydroquinones are oxidized to quinones in high yields in a platinum-catalyzed process with as low as 0.05 mol% catalyst. The aerobic oxidation is catalyzed by platinum nanoclusters trapped in a styrene-based polymer network (see scheme, PI Pt=polymer-incarcerated nanoclusters). The catalyst could be reused at least 13 times without any loss of catalytic activity.
- Miyamura, Hiroyuki,Shiramizu, Mika,Matsubara, Ryosuke,Kobayashi, Shu
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supporting information; experimental part
p. 8093 - 8095
(2009/04/13)
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- Nuclear amination catalyzed by fungal laccases: Reaction products of p-hydroquinones and primary aromatic amines
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(Chemical Equation Presented) Nuclear amination of p-hydroquinones with primary aromatic amines was catalyzed by fungal laccases (EC 1.10.3.2) from Trametes spec. and Myceliophthora thermophila. This is the first report of laccase-catalyzed synthesis of aminoquinones. Incubation of two compounds with laccase in the presence of oxygen resulted in the formation of the corresponding monoaminated or diaminated quinones. No hydroquinonoids were formed. Observed differences in the reaction courses for different p-hydroquinones and aromatic amines with different laccases are discussed.
- Niedermeyer, Timo H. J.,Mikolasch, Annett,Lalk, Michael
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p. 2002 - 2008
(2007/10/03)
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- Synthesis of pyrrolo[3,2-b]benzofurans and pyrrolo[3,2-b]naphthofurans via addition of a silyloxypyrrole to activated quinones
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The uncatalyzed reaction of N-(tert-butoxycarbonyl)-2-tert- butyldimethylsilyloxypyrrole 3 with 1,4-quinones bearing an electron withdrawing group at C-2 has been studied. Use of 1,4-quinones 4, 5 bearing an ester group at C-2 provided an efficient synthe
- Brimble, Margaret A.,Burgess, Caryn,Halim, Rosliana,Petersson, Maria,Ray, Jayanta
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p. 5751 - 5758
(2007/10/03)
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- Synthesis of methyl 3,6-dioxo-endo-tricyclo[6.2.1.0 2,7]undeca-4,9-diene-2-carboxylate as synthetic intermediate for conduritol deravatives
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Gentisic acid reacted with methyl iodide in HMPA to give 94% of the corresponding methyl ester. Its oxidation with Ag2O in toluene afforded 57% of methoxycarbonylbenzoquinone as yellow crystals. Reaction of the latter with cyclopentadiene resulted in formation of methyl 3,6-dioxotricyclo[6.2.1.02,7]undeca-4,9-diene-2-carboxylate (21%).
- Mamaghani,Pourali
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p. 347 - 349
(2007/10/03)
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- Catalyzed asymmetric Diels - Alder reactions of benzoquinone. Total synthesis of (-)-ibogamine
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The Diels - Alder reaction of 1,4-benzoquinone with 1,3-dienes catalyzed by Mikami's [Ti{(S)-binol(2 -)}Cl2] complex (binol = [1,1′-binaphthalene]-2,2′-diol) gives cycloadducts in good yield and in high enantiomer excess. A model is proposed to
- White, James D.,Choi, Younggi
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p. 4306 - 4327
(2007/10/03)
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- Triptycene analogs
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This invention provides analogs of triptycene which are useful as anticancer drugs, as well as for other uses. The potency of these compounds is in a similar magnitude as daunomycin, a currently used anticancer drug. Each compound of the invention produces one or more desired effects (blocking nucleoside transport, inhibiting nucleic acid or protein syntheses, decreasing the proliferation and viability of cancer cells, inducing DNA fragmentation or retaining their effectiveness against multidrug-resistant tumor cells).
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- Polymer-supported hypervalent iodine reagents in 'clean' organic synthesis with potential application in combinatorial chemistry
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A clean oxidation reaction of a variety of substrates using polymer-supported (diacetoxyiodo)benzene (PSDIB) which proceeds in high to excellent yield with maximum purity is described including isolation and regeneration of the polymer reagent.
- Ley, Steven V.,Thomas, Andrew W.,Finch, Harry
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p. 669 - 671
(2007/10/03)
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- Addition of cyclopentadiene and 2-trimethylsilyloxyfuran to quinones bearing a menthyl ester chiral auxiliary
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Addition of cyclopentadiene to 2-carbomethoxy-1,4-benzoquinone 9 afforded Diels-Alder adduct 10 using the Lewis acids ZnCl2 and ZnBr2 whereas the fragmenatation product 11 was the major product when using SnCl4 and TiCl4. Addition of cyclopentadiene to 1,4-benzoquinone 8 bearing a menthyl ester at C-2 afforded Diels-alder adduct 12 in moderate diastereomeric excess using ZnCl2 and ZnBr2 as Lewis acids. Use of TiCl4 and SnCl4 afforded the fragmentation product 13 also in moderate diastereomeric excess. Addition of 2-trimethylsilyloxyfuran to chiral naphthoquinone 4 and benzoquinone 8 afforded furofuran adducts 14 and 15 respectively as a 1:1 mixture of diastereomers.
- Brimble, Margaret A.,Duncalf, Letecia J.,Reid, David C. W.,Roberts, Tabitha R.
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p. 5363 - 5374
(2007/10/03)
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- Method for dyeing keratinous fibres using an aminoindole in combination with a quinone derivative
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Method for dyeing keratinous fibres, characterized in that at least one composition (A) containing at least one aminoindole in a medium appropriate for dyeing is applied to these fibres, the application of the composition (A) being preceded or followed by the application of a composition (B) containing, in a medium appropriate for dyeing, at least one quinone derivative chosen from ortho- or para-benzoquinones, ortho- or para-benzoquinone monoimines or diimines, 1,2- or 1,4-naphthoquinones, ortho- or para-benzoquinone sulphonimides, α,ω-alkylene-bis-1,4-benzoquinones, or 1,2- or 1,4-naphthoquinone monoimines or diimines, the aminoindoles and the quinone derivatives being chosen such that the difference in redox potential ΔE between the redox potential Ei of the aminoindoles, determined at pH 7 in a phosphate medium on a vitreous carbon electrode by voltametry, and the redox potential Eq of the quinone derivative, determined at pH 7 in a phosphate medium by polarography on a mercury electrode relative to the saturated calomel electrode, in such that
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- Process for dyeing keratinous fibres with a hydroxyindole in combination with a quinone derivative; and novel 1,4-benzoquinones
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Process for dyeing keratinous fibres, comprising the step of applying to these fibres at least one composition A containing, in a medium appropriate for dyeing, at least one mono- or di-hydroxyindole the application of the composition A being preceded or followed by the application of a composition B containing, in a medium appropriate for dyeing, at least one quinone derivative chosen from ortho- or para-benzoquinones, monoimines or diimines of ortho- or para-benzoquinones, 1,2- or 1,4-naphthoquinones, sulphonimides of ortho- or para-benzoquinones, α, ω-alkylene-bis-1,4-benzoquinones, or 1,2- or 1,4-naphthoquinone-monoimines or -diimines; the mono- or di-hydroxyindoles and the quinone derivatives being chosen such that the oxidation-reduction potential difference ΔE between the oxidation-reduction potential Ei of the mono- or di-hydroxyindoles, determined at pH 7 in a phosphate medium on a vitreous carbon electrode by voltametry, and the oxidation-reduction potential Eq of the quinone derivative determined at pH 7 in a phosphate medium by polarography on a mercury electrode and relative to a saturated calomel electrode is such that
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- 1,4-ADDITION OF 2-TRIMETHYLSILYLOXYFURAN TO QUINONES: A FACILE ROUTE TO THE FUROBENZOFURAN NUCLEUS
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The uncatalysed addition of 2-trimethylsilyloxyfuran (3) to a range of activated quinones (4) and (6) yields the crystalline adducts (5) and (7) in 51-91percent yield.This novel furofuran-annulation to a quinone system provides a facile entry to the furobenzofuran ring system.
- Brimble, Margaret A.,Gibson, Jennifer J.,Baker, Raymond,Brimble, Mark T.,Kee, Alex A.,O'Mahony, Mary J.
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p. 4891 - 4892
(2007/10/02)
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- 9,10-syn-PODOCARPANE DITERPENOIDS. VI. DIELS-ALDER CYCLOADDITION OF (ACETOXYVINYL)CYCLOHEXENES TO QUINONES
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The outcome of the cycloaddition reactions of 3-methoxycarbonyl-1,2-benzoquinone with 1-(1-acetoxyvinyl)cyclohexene and of 4-methoxycarbonyl-1,2-benzoquinone and 2-methoxycarbonyl-1,4-benzoquinone with 1-(1-acetoxyvinyl)- and 1-(2-acetoxyvinyl)-cyclohexene is described.
- Forte, Maurizio,Orsini, Fulvia,Pelizzoni, Francesca,Ricca, Giuliana
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- STUDIES ON QUINONES. XI. SYNTHESIS OF QUINONES FROM HYDROQUINONES BY USING MANGANESE DIOXIDE AND ACID-IMPREGNATED MANGANESE DIOXIDE.
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The preparation of a variety of quinones by oxidation of hydroquinones with manganese dioxide and manganese dioxide impregnated with nitric acid, in methylene chloride solution, is described.
- Cassis, R.,Valderrama, J. A.
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p. 347 - 356
(2007/10/02)
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- Synthesis and absolute configuration of the first optically active organic molecule with T symmetry: (-)-1,3,5,7-tetrakis3-trishomocubanyl)acetoxy>methyl>adamantane
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By starting from the Diels-Alder adduct 12 between 2-(methoxycarbonyl)-1,4-benzoquinone (11) and cyclopentadiene, the modified Barborak synthesis of D3-trishomocubane afforded (-)-2-(1S,3S,5R,6S,8R,10R)-D3-trishomocubaneacetic acid (19) whose esterification with 1,3,5,7,-tetrakis(hydroxymethyl)adamantane (27) gave (-)-28, the first T symmetric organic molecule with known absolute configuration.
- Nakazaki, Masao,Naemura, Koichiro
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p. 106 - 111
(2007/10/02)
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- STEREOCONTROLLED SYNTHESIS OF CLERODIN HOMOLOG - A SYNTHETIC APPROACH TO STRUCTURE-ACTIVITY RELATIONSHIPS -
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In order to elucidate the structure-activity relationships of the antifeeding diterpenes having a neo-clerodane skeleton, clerodin homolog 5 was stereoselectively synthetized through 18 steps via a key intermediate 11.Perhydrofurofuran ring in the synthesized homolog was more unstable than that of the natural product, and gave a tri-MeOH adduct 3 in a similar behavior to that of the model compound 1 and 2.
- Kojima, Yasuhiro,Kato, Natsuki
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p. 5033 - 5036
(2007/10/02)
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