- Synthesis, X-ray structure and binding properties of molecular clips based on dimethylpropanediurea
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New concave host molecules show strong noncovalent binding of hydroxybenzene derivatives by an induced fit mechanism (Ka up to 3.4 × 106 dm3 mol-1).
- Jansen, Rob J.,Rowan, Alan E.,De Gelder, Rene,Scheeren, Hans W.,Nolte, Roeland J. M.
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- Understanding the binding properties of phosphorylated glycoluril-derived molecular tweezers and selective nanomolar binding of natural polyamines in aqueous solution
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A modular synthetic platform for the construction of flexible glycoluril-derived molecular tweezers was developed. The binding properties of four exemplary supramolecular hosts obtained via this approach towards 16 organic amines were investigated by means of 1H NMR titration. In this work, we compare the Ka values obtained this way with those of three structurally related molecular tweezers and provide a computational approach towards an explanation of the observed behavior of those novel hosts. The results showcase that certain structural modifications lead to very potent and selective binders of natural polyamines, with observed binding of spermine below 10 nM. This journal is
- Heilmann, Michael,Knezevic, Melina,Piccini, Giovannimaria,Tiefenbacher, Konrad
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supporting information
p. 3628 - 3633
(2021/05/04)
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- Overriding Intrinsic Reactivity in Aliphatic C?H Oxidation: Preferential C3/C4 Oxidation of Aliphatic Ammonium Substrates
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The site-selective C?H oxidation of unactivated positions in aliphatic ammonium chains poses a tremendous synthetic challenge, for which a solution has not yet been found. Here, we report the preferential oxidation of the strongly deactivated C3/C4 positions of aliphatic ammonium substrates by employing a novel supramolecular catalyst. This chimeric catalyst was synthesized by linking the well-explored catalytic moiety Fe(pdp) to an alkyl ammonium binding molecular tweezer. The results highlight the vast potential of overriding the intrinsic reactivity in chemical reactions by guiding catalysis using supramolecular host structures that enable a precise orientation of the substrates.
- Heilmann, Michael,Knezevic, Melina,Piccini, Giovanni Maria,Tiefenbacher, Konrad
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supporting information
p. 12387 - 12391
(2020/07/04)
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- Regioselective bromination of 1,4-dimethoxy-2,3-dimethylbenzene and conversion into sulfur-functionalised benzoquinones
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The NBS bromination of 1,4-dimethoxy-2,3-dimethylbenzene has been examined under a variety of conditions in both 1,1,1-trichloroethane and benzotrifluoride. Four different bromination products have been isolated including the previously unknown 1-bromo-4-
- Aitken, R. Alan,Jethwa, Siddharth J.,Richardson, Neville V.,Slawin, Alexandra M.Z.
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supporting information
p. 1563 - 1566
(2018/03/29)
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- Composition for treatment of pathogens that are resistant to tetracyclines
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The invention relates to compounds and pharmaceutical compositions useful in combination with tetracyclines in the treatment of bacterial infections caused by Gram-positive and Gram-negative pathogens, with particular efficacy in tetracycline resistant st
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Paragraph 0105-0106
(2014/08/19)
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- COMPOSITION FOR TREATMENT OF PATHOGENS THAT ARE RESISTANT TO TETRACYCLINES
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The invention relates to compounds and pharmaceutical compositions useful in combination with tetracyclines in the treatment of bacterial infections caused by Gram- positive and Gram-negative pathogens, with particular efficacy in tetracycline resistant s
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Page/Page column 31
(2014/08/19)
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- Vitamin E metabolites: Synthesis of [D2]- and [D 3]-γ-CEHC
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Deuterated analogues of α- and γ-CEHC, main urinary and plasma metabolites of vitamin E, can be traced and accurately determined quantitatively by MS in complex matrices. In that regard, here we report the first synthesis of rac-[D3]-γ-CEHC together with a simple route to 7a,8a-[D2]-γ-CEHC through the set up of efficient procedures for the preparation of the corresponding deuterated hydroquinone building blocks. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Mazzini, Francesco,Galli, Francesco,Salvadori, Piero
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p. 5588 - 5593
(2008/02/04)
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- New Benzo[b]xanthones from Diels-Alder Reactions of Chromone-3- carboxaldehydes with ortho-Benzoquinodimethanes
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New benzo[b]xanthone derivatives, having substituents in the A and D rings, were prepared from cycloaddition reactions of chromone-3-carboxaldehydes with ortho-benzoquinodimethanes, generated in situ from 1,3-dihydrobenzo[c]thiophene 2,2-dioxide, followed
- Sandulache, Angela,Silva, Artur M. S.,Cavaleiro, Jose A. S.
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p. 551 - 563
(2007/10/03)
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- Molecular clips based on propanediurea. Exceptionally high binding affinities for resorcinol guests
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A series of new receptor molecules derived from 2,4,6,8-tetraazabicyclo[3.3.1]nonane-3,7-dione (propanediurea) is described. These molecules possess a cavity which is defined by two nearly parallel aromatic side walls positioned on top of a bis-urea frame
- Jansen,De Gelder,Rowan,Scheeren,Nolte
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p. 2643 - 2653
(2007/10/03)
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- Electro-organic reactions. Part 54: Quinodimethane chemistry; Part 2 - Electrogeneration and reactivity of o-quinodimethanes
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The electrochemical generation and characterisation of a variety of o-quinodimethanes (o-QDMs) are described together with the outcome of preparative experiments in which they are key intermediates. The quinodimethanes are conveniently formed, in DMF, by both direct and redox-catalysed electroreduction of 1,2-bis(halomethyl)arenes. Their predominant reaction is polymerisation to poly(o-xylylene) (o-PX) polymers. In the presence of dienophiles the electrogenerated o-QDMs may undergo efficient cycloaddition reaction and distinctions between the possible mechanisms have been attempted on the basis of voltammetric, preparative and stereochemical experiments. Contrary to the precedent of the corresponding methyl ester, diphenyl maleate radical-anion isomerises only slowly to the fumarate radical-anion, yet co-electrolysis of 2,3-bis(bromomethyl)-1,4-dimethoxybenzene and diphenyl maleate or diphenyl fumarate gives exclusively the corresponding trans-adduct. Co-electrolysis of dimethyl maleate with either 1,2-bis(bromomethyl)benzene (more easily reduced) or 2,3-bis(bromomethyl)-1,4-dimethoxybenzene (less easily reduced) gave only o-PX polymer. The results are rationalised in terms of a double nucleophilic substitution mechanism where electron transfer between dienophile radical-anion and dihalide is relatively slow. Where electron transfer from maleate or fumarate radical-anions is likely to be fast o-quinodimethanes are formed by redox-catalysis and they polymerise rather than undergo Diels-Alder reaction. Dimerisation of the dienophile radical-anions, with k2 = 104 to 105 M-1 s-1, does not apparently compete with nucleophilic substitution or, where relevant, electron transfer.
- Utley, James H.P.,Ramesh, Shalini,Salvatella, Xavier,Szunerits, Sabine,Motevalli, Majid,Nielsen, Merete F.
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p. 153 - 163
(2007/10/03)
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- Efficient synthesis of 5,8-disubstituted-1,4-dihydrobenzoxathiin-3-oxides and their isomeric structures, 4,7-disubstituted-1,3-dihydrobenzo[b] thiophene-2,2-dioxides
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Functionalized dihydrobenzoxathiin oxides and dihydrobenzothiophene-2,2-dioxides 11-18 have been prepared via trapping of sulfur dioxide under photolytic or ground state conditions.
- Attardo, Giorgio,Wang, Wuyi,Kraus, Jean-Louis,Belleau, Bernard
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p. 4743 - 4746
(2007/10/02)
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- Synthesis of a New Rigid Quinone-Amino Acid and Diels-Alder Extension to Higher Quinones
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Electron deficient cyclic α-amino acid derivatives bearing 1,4-benzoquinone and 1,4-anthraquinone side chains were synthesized by an novel route.The common precursor, 2-amino-4,7-dimethoxy-indan-2-carboxylic acid, may be incorporated into a peptide prior
- Kotha, Sambasivarao,Kuki, Atsuo
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p. 299 - 302
(2007/10/02)
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- Capture du paradimethoxyorthoquinodimethane:syntheses de quinones et d'un intermediaire de la daunomycinone
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New para-dimethoxyl and para-diacetoxy derivatives in the naphthalene, anthracene, naphthacene, naphtho(2,3-c)thiophene and benzo-c-thiophene series are synthesized via the trapping of o-quinodimethanes by various dienophiles.Among these compounds, and in
- Laduranty, Joelle,Lepage, Lucette,Lepage, Yves
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p. 1161 - 1167
(2007/10/02)
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