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Showing 1 to 20 of 39 for “"Hydrazones"”.
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Cation radical induced oxidative chemistry of hydrazones and oximes
… study of reactions of cation radicals with arylhydrazones. The objective of studying the reactions of cation radicals with arylhydrazones was to explore the cation radical induced oxidative cycloaddition of hydrazones to nitrites to give trisubstituted 1,2,4-triazoles.
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Spectroscopic studies of some heterocyclic hydrazones and their metal complexes
The PMR spectra of the two isomers of pyridine-2-aldehyde=2'-pyridyl hydrazone in carbon tetrachloride, dimethyl sulphoxide, and benzene solutions have been studied. Specific associations between PAPHY molecules and solvent molecules have been proposed to account for the observed solvent shifts. …
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Asymmetric synthesis of amines and amine derivatives: I. The cerium-mediated diastereoselective addition of organometallic reagents to chiral pyrrolidine hydrazones. II. The enantioselective addition of organolithium reagents to imines and hydrazones
Two conceptually different approaches to the asymmetric synthesis of amines and amine derivatives via the addition of organometallic reagents to the carbon-nitrogen double bond of azomethines has been investigated.
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Asymmetric α-Alkylation of Acyclic Ketones Utilizing Chiral Nonracemic N-Amino Cyclic Carbamate Hydrazones
Asymmetric variants of ketone α-alkylation are highly important given that numerous natural products, drugs, and related compounds exist as α-functionalized ketone or derivatives thereof. A method for asymmetric α-alkylation of ketones using N-Amino cyclic carbamate (ACC) chiral auxiliaries is …
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DESIGN AND SYNTHESIS OF PURINE BASED NEUROPROTECTORS AND NOVEL SYNTHETIC METHODS FOR THE TRIFLUOROMETHYLATION OF ALDEHYDE HYDRAZONES
… C(sp<sup>2</sup>−H)-trifluoromethylation of hydrazones would give access to the αtrifluoromethylated hydrazones that can serve as intermediates in the synthesis of pharmaceutically interesting, fluorinated compounds. Herein, we demonstrate two different synthetic routes for the …
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New Methods for the α-Functionalization of Thioesters and Activated Hydrazones and an Application Toward the Total Synthesis of Apratoxin D
… of chiral N-amino cyclic carbamate (ACC) hydrazones, a new methodology developed by our group. Herein we demonstrate the utility of this method for convergent total syntheses.</p>
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Development and application of palladium-catalyzed carbon-nitrogen bond forming reactions
… for the preparation of N-aryl benzophenone hydrazones is described. The use of 1-2.5 mol % of a Pd/BINAP based catalyst provides N-aryl benzophenone hydrazones in good yields. Using a Pd/9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (Xantphos) catalyst the desired hydrazones are produced …
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Asymmetrische Synthese von Gamma-Hydroxy-Alpha-Aminosäuren, 1,3-Aminoalkoholen und 2-Amino-3-Phosphonopropionsäure
… substrates. Starting from aldehyde SAMP-hydrazones we obtained beta-hydroxy SAMP-hydrazones in a titanium-mediated aza-analogous aldol reaction. After protection, 1,2-addition and cleavage of the chiral auxiliary the products could be isolated over five steps in 30 to 54% overall yield …
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Cascade Transformations in Organic Synthesis: I. The Interception of Carbene Alkyne Metathesis Intermediates II. Photo-Activation of Hydrazones III. Organocatalyzed Cascade Conjugate Addition/Aldol Annulation of Organoboronates
This dissertation describes cascade transformations in constructing complex building blocks in synthetic organic chemistry. It includes the interceptions of carbene alkyne metathesis intermediates, boron enolate intermediates, fused cyclopropene intermediates, and boronic acid intermediates. First, …
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Asymmetrische Synthese neuer planar- und zentral-chiraler Ferrocenylliganden
… (de >= 96%). The monosubstituted bis-SAMP-hydrazones prepared, could either undergo a second diastereoselective ortho-substitution under the same conditions to lead to 2,2'-substituted bis-SAMP-hydrazones or could be cleaved to produce mono-substituted 1,1'-bisbenzoylferrocenes. In case of …
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(Trimethylsilyloxy)acrylsäureester in der organischen Synthese
… easily be transformed into alpha-oximes, alpha-hydrazones as well as gamma-hydroxy-alpha-keto esters under mild conditions and in high yields.
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Trifluoromethyl ketones: Potential insecticides towards Anopheles gambiae
… towards synthesis of oximes, oxime ethers, and hydrazones as potential prodrugs to prevent immediate hydration and reach the central nervous system. The synthesis of various oximes, oxime ethers, and hydrazones has been shown to give cimpounds toxic to Anopheles gambiae within 3- to 4-fold of …
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Nucleophilic Addition to Azoalkenes; Diastereoselective Synthesis of β-Hydroxy Ketones and β,γ-Fused γ-Lactams
… of Grignard reagents to α-epoxy N-sulfonyl hydrazones–directed by the alkoxide of 1-azo-3-alkoxy propenes formed in situ via base-induced ring opening of the epoxide–leads to the syn-selective production of α-alkyl-β-hydroxy N-sulfonyl hydrazones with α-quaternary centers. This …
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Asymmetric synthesis of lignans and of α-heteroaryl)alkylamines employing the SAMP-/RAMP-hydrazone method
… of heteroarenyllithium species to SAMP-/RAMP-hydrazones, has been developed. Moreover the novel methodology was successfully applied to the synthesis of biologically interesting compounds such as a-aminoacids and b-aminosulfones.
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Asymmetrische Synthese von 1,3-Aminoalkoholen und deren Anwendung zur Synthese von Azetidinen und 1-Azabicyclen
… N,O-protected 1,3-aminoalcohols using SAMP/RAMP Hydrazones and their application in asymmetric synthesis. Furthermore, the asymmetric synthesis of 2-substituted azetidines was developed. - Asymmetric synthesis of 1,3-aminoalcoholsA flexible diastereo- and enantioselective synthesis of …
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The Effect of acetaminophen on isoniazid metabolism
… and Hz present in the samples were converted to hydrazones by reaction with p-chlorobenzaldehyde. The hydrazones were then extracted with methylene chloride. The AcINH and DiAcHz remaining in the aqueous layer were then converted to INH and AcHz, respectively, by partial acid hydrolysis. The …
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Asymmetrische Synthese planar- und zentral-chiraler 1,2,3-trisubstituierter und 1,3-disubstituierter Ferrocene
… process. Starting from several ferrocenyl-SAMP-hydrazones, different donor functionalities were diastereoselectivly introduced using a second ortho-directing group. Furthermore the exchange of the auxiliary by electrophiles gave rise to more structurally-unique ligands.
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Advancements in the synthesis of distorted tricoordinate phosphorus compounds and their use as platforms in reductive chemistries
… explores the activation of both hydrazine and hydrazones by a distorted phosphoramidite and initial results in the use of these phosphoranes as platforms for hydrogen atom transfer chemistry. Chapter five presents a unique reaction in the formation of an oxazaphosphole that shows promise to …
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Synthesis and Characterization of Bexarotene Derivatives with Potential Biological Activity // Получаване и охарактеризиране на бексаротенови производни с потенциална биологична активност
… with carbonyl compounds to form the target hydrazones. Hydrazide-hydrazone compounds have attention in the last few decades because of the diverse pharmacological effects they possess. Hydrazones and their derivatives are known to exhibit a wide range of pharmacological effects such as …
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Neue Ankergruppen für die enantioselektive kombinatorische Festphasensynthese
… and reduction lead to the "SAMP-resin". Hydrazones based on this "SAMP-resin" were used in alpha-alkylations at -100 øC leading to ee- values up to 86.3%. A library of 24 chiral ketones was synthesized at -72 øC. The purities of the products exeeded 99% and they showed moderate ee-values …
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