- Mechanically Interlocked Profragrances for the Controlled Release of Scents
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The synthesis of a series of interlocked profragrances and the study of the controlled release of the corresponding scents are reported. The structures of the profragrances are based on a [2]pseudorotaxane scaffold with a fumaramate thread derived from perfumery alcohols and a tetrabenzylamido ring. The delivery of the scents was accomplished by sequential thermal dethreading and further enzymatic hydrolysis. Alternatively, the dethreading can be achieved by increasing the polarity of the solvent or photochemical isomerization. The temperature of dethreading can be modulated by the steric demand of the ends of the thread, which allows the selection of different precursor structures depending on the desired rates of delivery. The inputs and outputs for the controlled release of the interlocked profragrances correspond to those of YES or AND logic gates.
- Alajarin, Mateo,Berna, Jose,Lopez-Sanchez, Jorge,Pastor, Aurelia
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supporting information
p. 15045 - 15054
(2021/10/20)
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- Reduction of carbonyl compounds via hydrosilylation catalyzed by well-defined PNP-Mn(I) hydride complexes
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Reduction reactions of unsaturated compounds are fundamental transformations in synthetic chemistry. In this context, the reduction of polarized double bonds such as carbonyl or C=C motifs can be achieved by hydrogenation reactions. We describe here a highly chemoselective Mn(I)-based PNP pincer catalyst for the hydrosilylation of aldehydes and ketones employing polymethylhydrosiloxane (PMHS) as inexpensive hydrogen donor. Graphic abstract: [Figure not available: see fulltext.]
- Weber, Stefan,Iebed, Dina,Glatz, Mathias,Kirchner, Karl
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p. 635 - 639
(2021/06/17)
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- SELECTIVE HYDROGENATION OF ALDEHYDE WITH RU/BIDENTATE LIGANDS COMPLEXES
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The present invention relates to processes for the reduction by hydrogenation, using molecular H2, of a C5-C20 substrate containing one or two aldehydes functional groups into the corresponding alcohol or diol, characterized in that said process is carried out in the presence of —at least one catalyst or pre-catalyst in the form of a ruthenium complex having a coordination sphere of the N2P2O2, wherein the coordinating atoms N2 are provided by a first bidentate ligand, the coordinating atoms P2 are provided by a second bidentate ligand and the coordinating atoms O2 are provided by two non-linear carboxylate ligands; and —optionally of an acidic additive.
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Paragraph 0178
(2014/09/03)
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- HYDROGENATION OF ESTERS OR CARBONYL GROUPS WITH TETRADENTATE AMINO/IMINO-THIOETHER BASED RUTHENIUM COMPLEXES
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The present invention relates to the field of catalytic hydrogenation and, more particularly, to the use of specific ruthenium catalysts, or pre-catalysts, in hydrogenation processes for the reduction of ketones and/or aldehydes into the corresponding alcohol respectively. Said catalysts are ruthenium complexes comprising a tetradentate ligand (L4) coordinating the ruthenium with: two nitrogen atoms, each in the form of a primary or secondary amine (i.e. a NH2 or NH group) or N-alkyl imine functional groups (i.e. a C═N group), and two sulfur atoms, each in the form of thioether functional groups.
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Paragraph 0112
(2013/10/22)
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- Asymmetric hydrogenation of ketones with H2 and ruthenium catalysts containing chiral tetradentate S2N2 ligands
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Getting more for less: In the presence of H2 and a base, air- and moisture-tolerant RuII complexes catalyze the hydrogenation of ketones and aldehydes with excellent activity and chemoselectivity, and with enantioselectivity of up to 95 % under mild conditions. The ratio of substrate to catalyst can be lowered to 106:1. The reactions tolerate scale-up and can be carried out with almost no solvent. A base-free method is available for base-sensitive substrates. Copyright
- Patchett, Ruth,Magpantay, Iris,Saudan, Lionel,Schotes, Christoph,Mezzetti, Antonio,Santoro, Francesco
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supporting information
p. 10352 - 10355
(2013/10/21)
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- Unexpected role of anionic ligands in the ruthenium-catalyzed base-free selective hydrogenation of aldehydes
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Bigger and better: The replacement of anionic chloride ligands in Noyori-type [(diamine)(diphosphine)RuCl2] catalysts with bulky carboxylate ligands enabled the efficient selective hydrogenation of a variety of aldehydes under base-free conditions (see scheme). Turnover numbers of up to 100 000 were reached in the presence of a bulky carboxylic acid co-catalyst. This type of catalytic system probably operates through an inner-sphere mechanism. Copyright
- Dupau, Philippe,Bonomo, Lucia,Kermorvan, Laurent
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supporting information
p. 11347 - 11350
(2013/11/06)
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- HYDROGENATION OF ESTERS OR CARBONYL GROUPS WITH TETRADENTATE AMINO/IMINO-THIOETHER BASED RUTHENIUM COMPLEXES
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The present invention relates to the field of catalytic hydrogenation and, more particularly, to the use of specific ruthenium catalysts, or pre-catalysts, in hydrogenation processes for the reduction of ketones and/or aldehydes into the corresponding alcohol respectively. Said catalysts are ruthenium complexes comprising a tetradentate ligand (L4) coordinating the ruthenium with: - two nitrogen atoms, each in the form of a primary or secondary amine (i.e. a NH2 or NH group) or N-alkyl imine functional groups (i.e. a C=N group), and - two sulfur atoms, each in the form of thioether functional groups.
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Page/Page column 21-23
(2012/07/13)
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- Processes for producing levosandal and levosandol
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The present invention relates to processes for producing 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-butenal and 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol using heterogeneous bifunctional catalysts with a good yield. There is provided a process for producing 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-butenal by the cross-aldol condensation between campholenic aldehyde and butanal using bifunctional heterogeneous catalysts in the presence of controlled amounts of an aliphatic alcohol; and a process for producing 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol useful as perfume, starting from 2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-butenal through a MPV reduction using an acid-base bifunctional heterogeneous catalyst. Both process can be coupled in a cascade process which involves the cross-aldol condensation between campholenic aldehyde and butanal followed by the Meerwein-Ponndorf-Verley (MPV) reduction in the presence of a secondary alcohol using the same heterogeneous bifunctional catalyst for obtaining (2-ethyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol).
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Page/Page column 5-6
(2010/10/19)
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- A practical and highly chemoselective hydrogenation of aldehydes with a copper catalyst
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A practical hydrogenation of aldehydes mediated by an inexpensive and easily available base metal, copper, is reported. A copper complex associated with 1,4-bis(diphenylphosphino)butane (DPPB) hydrogenates α,β- unsaturated aldehydes in a highly chemoselective fashion to give allylic alcohols with improved catalytic productivities. The reaction system was also effective for the conversion of simple aldehydes to the corresponding alcohols. Georg Thieme Verlag Stuttgart.
- Shimizu, Hideo,Sayo, Noboru,Saito, Takao
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experimental part
p. 1295 - 1298
(2009/10/24)
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- Process for hydrogenation of carbonyl and iminocarbonyl compounds using ruthenium catalysts comprising tetradentate diimino-diphosphine ligands
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A process for the hydrogenation, using molecular hydrogen (H2), of a catalytic system, wherein the catalytic system comprises a base and a complex of formula; (II) wherein Y represents simultaneously or independently a hydrogen or halogen atom, a hydroxy group, or an alkoxy, carboxyl or other anionic radical, and N2P2 is a tetradentate diimine-diphosphino ligand.
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- (E)-(R)-2-alkyl-4-(2,2,3,-Trimethylcyclopent-3-en-1-yl)-2-buten-1-ol, process for preparing the same, and use thereof
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An (E)-(R)-2-alkyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)-2-buten-1-ol represented by formula (I): wherein R represents an alkyl group having 1 to 3 carbon atoms, and a process for preparing the same comprising hydrogenating a corresponding (E)-(R)-2-alkyl-4-(2,2,3-trimethylcyclopent-3-en-1-yl)-2-buten-1-al in the presence of a ruthenium-phosphine complex as a catalyst, a base comprising an alkali metal or an alkaline earth metal, and an amine. The compound (I) has an excellent sandalwood oil odor.
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- Process for preparing unsaturated alcohol
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The object of the present invention resides in efficiently providing unsaturated alcohol from an α,β-unsaturated aldehyde. The present invention provides a process for preparing unsaturated alcohol by selectively reducing the aldehyde group of an α,β-unsaturated aldehyde in the presence of a primary or a secondary alcohol having 2 to 8 carbon atoms using an aluminum alcoholate to produce an unsaturated alcohol such as compounds represented by the formula (III). STR1 (wherein R represents an alkyl group having 1 to 3 carbon atoms) wherein the reaction is carried out with addition of a protonic acid.
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