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Showing 1 to 20 of 41 for “"Allylic Alcohols"”.
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Catalytic, Enantioselective Cyclopropanation of Allylic Alcohols
In mechanistic investigations, spectroscopic examinations and reaction surveys of substrate, reagent, and promoter were combined with solid-state evidence concerning the active form of the catalytically operative species to rationalize many of the observed features and trends of this system. …
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Asymmetric Transfer Hydrogenation of Secondary Allylic Alcohols
… method that transforms racemic secondary allylic alcohols into optically active secondary alcohols. The key step in this methodology occurs through a ruthenium catalyzed tandem isomerization and asymmetric transfer hydrogenation reaction. This reaction is a one pot, two-step process, which …
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Synthesis and synthetic transformations of allylic alcohols, epoxy alcohols, and 1,2-cyclic sulfates
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1988.
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The Synthetic Utility of Enol Derivatives and the Directed Aryltitanation of Homoallylic and Allylic Alcohols
… is less developed. Directing groups, such as homoallylic and allylic alcohols, may help overcome the poor reactivity of alkenes towards carbometalation. Herein the alcohols direct a highly diastereoselective aryltitanation to the proximal carbon–carbon double bond. Reactions with homoallylic …
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Conjugate Additions and Transposition of the Allylic Alcohols of Enol Ethers of 1, 2-Cyclohexanedione.
<p>A variety of protected enolic forms of 1, 2-cyclohexanedione was prepared as substrates for conjugate addition studies using organocopper reagents. The sequence involved the enol ether preparation via the enolate, alkylation with an organometalic reagent, and oxidative rearrangement with …
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Application of sulfonimidoyl substituted allyltitanium (IV) complexes to the asymmetric synthesis of alkenyloxiranes, 2,3-dihydrofurans, tetrahydrofurans, unsaturated proline analogues and allylic alcohols
… to high yields. An asymmetric synthesis of allylic alcohols from allylic sulfoximines and aldehydes is described in chapter 4. Lithiation and titanation of cyclic and acyclic allylic sulfoximines with ClTi(NEt2)3 and subsequent treatment with aldehydes gave, as described previously, enantio- …
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Nickel-catalyzed coupling reactions and synthetic studies toward ent-dioxepandehydrothyrsiferol via an epoxide-opening cascade
… coupling represent two methods of preparing allylic alcohols. Most asymmetric transition metal-catalyzed methods of preparing enantiomerically enriched allylic alcohols rely on chiral ligands. The nickel-catalyzed allene--aldehyde coupling exploits the axial chirality in 1,3-disubstituted …
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Nickel-catalyzed intermolecular reductive couplings of alkynes and aldehydes ; Enantioselective synthesis of (-)-terpestacin and structural revision of siccanol using catalytic stereoselective fragment couplings and macrocyclizations
… reaction to yield di- and trisubstituted allylic alcohols with high stereoselectivity and regioselectivity. In most cases, a 1:1 ratio of alkyne to aldehyde was sufficient for efficient coupling. The yield and regioselectivity were strongly dependent on the phosphine ligand, but the …
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Vanadium-katalysierte, asymmetrische Epoxidierung von Allylalkoholen
… the vanadium-catalysed asymmetric epoxidation of allylic alcohols using enantiopure hydroxamic acids as ligands is described. The newly synthesised hydroxamic acids were derived from bicyclo[2.2.1]heptanes containing chiral centres, as well as from planar chiral [2.2]paracyclophanes and …
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Palladium-katalysierte enantioselektive Synthese allylischer Thiocarboxylate und Palladium-katalysierte Deracemisierung allylischer Carbonate
… topic of this thesis is the palladium-catalyzed allylic alkylation of potassium thioacetate (KSAc) und potassium thiobenzoate (KSBz) with racemic cyclic and acyclic allylic esters having a symmetrically substituted carbon skeleton by using the Trost ligand. By this method the corresponding …
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Designing new chiral hydroxamic acid ligands for the asymmetric epoxidation reaction in water
… the course of this project, a wide range of allylic alcohols were epoxidised under mild reaction conditions. The target epoxides were isolated in good-to-excellent yields with up to 94% ee. To further develop the project, we also report that the range of substrates has been extended to …
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Asymmetrische Synthese funktionalisierter Homoallyl- und Homopropargylalkohole mittels der Sulfoximin-Route
… of diastereomeric and enantiomeric pure allylic alcohols. Via the sulfoximine-route by Gais et al. new chiral homoallyllic alcohols were synthesized. Elimination of the sulfoximine-group lead to optically pure homopropargylic alcohols. Via Nickel-catalysed cross-coupling reactions …
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Asymmetrische Synthese und stereoselektive Substitution allylischer Sulfoximin-funktionalisierter Homoallylalkohole
Enantiopure acyclic (E)- and (Z)-configured allylic sulfoximines have been synthesized from N,S-dimethyl-S-phenylsulfoximine and aldehydes via the addition-elimination-isomerization route. Titanation of lithiated (E)- and (Z)-configured allylic sulfoximines with Chlortrisdiethylanimotitan and …
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Asymmetrische Synthese von allylischen Alkoholen mittels Palladium-katalysierter asymmetrischer Transformation von allylischen Carbonaten und Synthese neuer Sulfoximin-Phosphane
… synthesis of synthetically interesting allylic alcohols by Palladium-catalyzed allylic substitution. For this substitution reaction the hydrogen carbonate ions are used as nucleophil and racemic allylic carbonates or acetates as racemic substrates. This reaction can also be called …
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Synthesis of Heterometallic nitridoruthenium(VI) Complexes With Nickel, Palladium, or Platinum: New Catalysts for the Aerobic Oxidation of Alcohols
… as a catalytic aerobic oxidant of organic alcohols is explored. The complex [PPh4][Ru(N)Me2(mu2 -O)2Pd((-)-sparteine)] oxidizes aryl and allyl alcohols to their corresponding aldehydes. The complex also catalytically rearranges allylic alcohols to their corresponding unsaturated aldehydes. …
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Katalytische, enantioselektive Synthesen von Diarylmethanolen und Allylalkoholen
… vinylation of aldehydes for the generation of allylic alcohols was developed and optimised. Allylic alcohols are very important intermediates for the organic synthesis of natural products and pharmaceuticals. As such, alkenyl boronic acids were transmetalated with diethylzinc to form a mixed …
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Oxo-metal catalysed reactions of unsaturated alcohols
… substituted salicylaldéhydes and chiral 2-aminoalcohols are also described along with a D(-)-2,3- butandiol complex of dioxomolybdeniam(VI ). As in a number of examples recently reported in the literature, epoxidation of geraniol and related compounds in the presence of these catalysts showed …
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Applications of Green Chemistry in Asymmetric Transfer Hydrogenation and Chiral Separations
… and analytical chemistry. More specifically, allylic and chiral alcohols are abundant in natural sources such as in essential oils, and widely utilized as starting materials. They are also major components in food, fragrance, biocides and the pharmaceutical compounds. In this thesis, I report …
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