- Design and synthesis of urea-linked aromatic oligomers-a route towards convoluted foldamers
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Herein we report the design and synthesis of crescent-shaped and helical urea-based foldamers, the curvature of which is controlled by varying the constituent building blocks and their connectivity. These oligomers are comprised of two, three or five alternating aromatic heterocycles (pyridazine, pyrimidine or pyrazine) and methyl-substituted aromatic carbocycles (tolyl, o-xylyl or m-xylyl) connected together through urea linkages. A crescent-shaped conformational preference is encoded within these π-conjugated urea-linked oligomers based on intramolecular hydrogen bonding and steric interactions; the degree of curvature is tuned by the urea connectivity to the heterocycles and the aryl groups. NMR characterization of these foldamers confirms the intramolecular hydrogen-bonded conformation expected (Z,E configuration of the urea bond) in both the pyridazyl and pyrimidyl foldamers in solution. An X-ray crystal structure of the N3,N6-diisobutylpyridazine-4,6- diamine-o-tolyl urea-linked foldamer (4) confirms the presence of N-H...N hydrogen bonds between the heterocyclic nitrogen atom and the free hydrogen of the urea linkage. Additionally, the tolyl methyl group interacts unfavourably with the urea carbonyl oxygen, thus destabilising the alternate planar conformation.
- Mousseau, James J.,Xing, Liyan,Tang, Nathalie,Cuccia, Louis A.
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supporting information; experimental part
p. 10030 - 10038
(2010/06/15)
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- One-pot reaction as an efficient method for rigid molecular tweezers
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(Equation Presented) Rigid molecular tweezers are compounds of increasing scientific interest. As the structural requirements for such compounds are highly specific, few types of these tweezers are thus far known. The preparation of examples of rigid larg
- Havlik, Martin,Kral, Vladimir,Kaplanek, Robert,Dolensky, Bohumil
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supporting information; experimental part
p. 4767 - 4769
(2009/05/31)
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- 1,3-Dihydroxybenzene derivatives and colorants containing said compounds
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1,3-Dihydroxybenzene derivatives of general formula (I) or (Ia) or physiologically tolerated, water-soluble thereof wherein R′1 denotes substituted pyridyl group, a pyrimidyl group, a group of formula (IIa) or (IIIa) and the dyeing agents for keratin fibers containing these compounds.
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- One step hair coloring compositions using salts
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A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.
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- Transition metal complexes as dye forming catalysts in hair coloring compositions
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A hair coloring composition comprising a first composition which comprises: (a) a dye forming transition metal salt or complex; which is first applied to the hair; and a second composition which comprises the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an aminophenol, a polyhydric phenol a catechol and mixtures thereof.
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- Enhanced color deposition for hair with sequestering agents
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Hair coloring compositions which comprise: (A) non-nitrogenous chelating agents from the group consisting of polyphosphate; phosphonates; hydroxycarboxylates; polyacrylates; zeolite; and mixtures thereof; (B) an oxidative dye primary intermediate; and (C) an oxidative dye coupler; (D) and water are described. The present invention also relates to a method for coloring hair which comprises contacting said hair with a hair coloring composition as described above.
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- Process for dyeing keratinous fibers with aminoindoles and oxidation dye precursors at basic Ph's and dyeing agents
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The invention relates to a process for dyeing keratinous fibres, which consists in applying to these fibres a composition containing, in a suitable medium for dyeing, at least one coupler of formula: STR1 where R1 denotes hydrogen or alkyl, R2 and R3 denote hydrogen, alkyl, COOR' where R' is alkyl or hydrogen, at least one of the groups R2 and R3 denoting hydrogen, R4 denotes hydrogen, alkyl, hydroxyalkyl, polyhydroxyalkyl or aminoalkyl, Z1 and Z2 denote hydrogen, alkyl, hydroxyl, halogen, alkoxy, at least one of the groups Z1 and Z2 is other than hydrogen at least one oxidation dye precursor, at least one oxidizing agent, the pH of the composition applied to the fibres being higher than 7.
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- Methods for dyeing keratinous fibers with compositions which contain aminoindole couplers, oxidation dye precursors, and oxidizing agents at acid pHs
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A method for dyeing keratin fibers, wherein a composition is applied to said fibers which contains, in a suitable dyeing medium, at least one coupler having formula (I) STR1 wherein R1 is hydrogen or alkyl; R2 and R3 are hydrogen, alkyl, COOR', where R' is alkyl or hydrogen; R4 is hydrogen, hydroxyalkyl, alkyl, polyhydroxyalkyl or acetyl or aminoalkyl wherein the amine may be mono- or disubstituted by alkyl; Z1 and Z2 are hydrogen, alkyl, hydroxy, halogen, alkoxy or a salt thereof; at least one precursor of an oxidation hair dye; and at least one oxidizing agent, the pH of the composition applied to the fibers being less than 7.
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- 3-substituted para-aminophenols
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The invention concerns the use of a 3-substituted para-aminophenol as an oxidation dye precursor for dyeing keratinous fibres, in particular human hair. The 3-substituted para-aminophenol has formula: STR1 where R1 represents alkyl, alkenyl, mono- or polyhydroxyalkyl, nitrile, cyanoalkyl, halogenoalkyl, aminoalkyl or alkoxyalkyl and R2 represents hydrogen, alkyl or mono- or polyhydroxyalkyl, provided that when R2 is hydrogen R1 is not methyl or trifluoromethyl, and to addition salts thereof with an acid. The invention also concerns dye compositions containing compound (I). The invention further concerns novel 3-substituted para-aminophenols.
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- Process for dyeing keratinous fibres with oxidation bases combined with an iodide and dyeing composition employed
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A process for dyeing keratinous fibers employs a dye composition containing an oxidation base selected from a paraphenylenediamine, an N,N'-diphenylalkylene diamine, a para-aminophenol, an ortho-aminophenol, an ortho-phenylenediamine or a heterocyclic oxidation base, in combination with iodide ions. The application of this dyeing composition to the keratinous fibers is preceded or followed by the application to the fibers of a composition containing hydrogen peroxide.
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- Process for dyeing keratinous fibers combining isatin or its derivatives with a tri-, tetra- or pentasubstituted aniline or with a bisphenylalkylenediamine, and dyeing agents
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The invention relates to a process for dyeing keratinous fibres, comprising the simultaneous or sequential application of a component (A) containing at least one compound of formula (I): STR1 in which: R1 denotes hydrogen, alkyl, acetyl, benzoyl, phenyl or C1 -C4 carboxyalkyl, R2 and R3 denote hydrogen, alkyl, alkoxy, hydroxyalkyl, amino, halogen, nitro, alkylphenyl, phenyl, alkylamino or hydroxyalkylamino, and a component (B) containing at least (i) a compound of formula (II): STR2 in which: Y denotes OH or NR8 R9, R8 and R9, which are identical or different, denote hydrogen, aminoethyl, hydroxyethyl or C1 -C4 alkyl, R4 to R7 independently of each other denote a hydrogen atom, a C1 -C4 alkyl, a chlorine, a C1 -C4 alkoxy, an acetylamino, an aryloxy, not more than two of the groups R4 to R7 denote a hydrogen atom, excluding 2,5-dimethoxy-1,4-diaminobenzene, and the cosmetically acceptable salts, or (ii) a bisphenylalkylenediamine. It also relates to the dyeing agents for implementing it.
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