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Showing 1 to 20 of 25 for “"sulfoximines"”.
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Synthesis of new sulfoximines for asymmetric synthesis and pseudopeptides
Sulfoximines have attracted attention due to their applicability as chiral auxiliaries, ligands in asymmetric catalysis, and building blocks in pseudopeptides. A number of approaches have been investigated for their synthesis, which allows the preparation of various derivatives in a relatively …
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New C 1- and C 2-symmetric sulfoximines : synthesis and application in enantioselective metal catalysis
… the preparation of new C1- and C2-symmetric sulfoximines (N,N- and P,N-ligands) for enantioselective metal catalysis is described. Guided by the excellent level of enantioselectivity observed using aminosulfoximine in the Cu-catalyzed Mukaiyama-aldol reaction, modifications of this class of …
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Oxidation & 1, 5-hydride shift of sulfoximine derivatives
… REQUEST.] Oxidation of N-alkyl and N-aryl sulfoximines and 1,5-hydride shift of S-alkenyl sulfoximines have been studied. Oxidation of N-alkyl sulfoximines using dimethyldioxirane gave sulfones and nitroso derivatives. A mechanism for the process was proposed. Thermal isomerization and …
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Cyclische Alpha- und Ortho-Lithio-S-Phenyl-Sulfoximine : Synthese, Funktionalisierung und Umlagerung
… the synthesis of different substituted cyclic sulfoximines suitable for the use as ligands in the asymmetric 1,4-addition. This aim was tried to achieve through synthesis of different substituted cyclic sulfoximines for the use as chiral nontransferable ligands in the stoichometric conjugate …
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Neue heterocyclische Sulfoximine
… describes the synthesis of novel heterocyclic sulfoximines. Being aware the enormous application potential of heterocyclic sulfoximines (e.g. as bioactive compounds or as ligands), we were inspired to expand the existing protocols for the synthesis of this class of compounds. In the first part …
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Synthesis of chiral phosphino-sulfoximines through phospha-Michael addition and their evaluation as 1,5-P,N-Ligand in asymmetric allylic alkylation
… work describe the synthesis of new phosphino-sulfoximines and their application as 1,5-P,N-ligand in palladium-catalyzed asymmetric allylic alkylation. The key step of the synthesis of phosphino-sulfoximines is the introduction of the phosphorus via a phospha-Michael addition with …
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Chirale Tris(amido)titanaallylsulfoximine: Stereoselektive Hydroxyalkylierung, Struktur und Dynamik
… reactions of E- and Z-configured allylic sulfoximines. Titanation of lithiated allylic sulfoximines with chlorotrisdiethylaminotitan and subsequent reaction of the resulting mono(2-alkenyl)tris(diethylamido)titan(IV)-complexes with aldehydes yielded the corresponding …
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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
… N-tert-butylsulfonyl imino ester. Activation of sulfoximines through methylation, of the sulfoximine group follwed by Cl substitution, and subsequent DBU-mediated, intramolecular, nucleophilic substitution afforded the optically-pure proline derivatives in medium to high yields. An asymmetric …
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Asymmetrische Synthese von allylischen Alkoholen mittels Palladium-katalysierter asymmetrischer Transformation von allylischen Carbonaten und Synthese neuer Sulfoximin-Phosphane
… On this occasion, interesting new classes of sulfoximines, alpha-(N-sulfoximido) phosphines, phosphine oxides and phosphonates, were synthesized from N-vinyl sulfoximines. These new sulfoximines could possibly serve as ligands or as an analogue to the bioactive alpha-aminophosphonic acids. …
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Synthese chiraler Sulfone aus Sulfoximinen in Lösung und an fester Phase
Synthesis of chiral sulfones using sulfoximines in solution and on solid phase Abstract: Allylic sulfoximines were synthesised in a one pot reaction starting from (S)-N,S-dimethylphenylsulfoximine in high yields. The following g-hydroxyalkylation with functionalised aldehydes was achieved with …
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Synthese neuartiger Sulfoximine für die asymmetrische Metallkatalyse
In this work various beta-hydroxysulfoximines was synthesized. We proved their catalytic applicability in asymmetric phenyl transfer reactions onto aldehydes. Enantiomerically enriched diarylmethanols have been prepared by catalyzed asymmetric phenyl transfer reactions onto aromatic aldehydes with …
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Asymmetrische Synthese und stereoselektive Substitution allylischer Sulfoximin-funktionalisierter Homoallylalkohole
… 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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Enantioselective synthesis of cyclic beta-amino alcohols via tandem hydroalumination-cyclization-reduction of ethoxycarbonyl vinyl sulfoximines and application to the synthesis of potential aggrecanase inhibitors
… alcohols starting from ethoxycarbonyl vinyl sulfoximines, which are prepared from cyclic bis(allylsulfoximine)titanium complexes and N-tert-butylsulfonyl alpha-imino ester. The application of sulfoximine substituted bicyclic 1,2-amino alcohol in the synthesis of potential aggrecanase …
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Asymmetrische Synthese von bicyclischen Alpha-Aminosäuren durch intramolekulare Pauson-Khand-Reaktion von l-Alkenylsulfoximinen und Festphasensynthese mit Allylsulfoximinen
… (S)-N,S-Dimethyl-S-phenylsulfoximine allylic sulfoximines could easily be prepared in 55-70% yield following a well established addition elimination isomerization route. A regio and diastereoselective allylation of N-tert-Butysulfonyliminoester with titanated allylic sulfoximines led to …
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Delta-Hydroxy-beta,beta-disubstituierte-beta-Aminosäuren: asymmetrische Synthese und Überführung in Dipeptide
… with aldehydes or ketones to give allylic sulfoximines. The latter ones were gamma-hydroxylated using aldehydes, thus giving access to the two new stereogenic centers containing delta-N-methylsulfonimidoyl-substituted homoallylic alcohols which in the following step were aminated to …
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Asymmetrische Synthese 3-substituierter 4-Methylenproline und Untersuchungen zur Metathese mit vinylischen Sulfoximinen
… the corresponding mixture of E and Z allylic sulfoximines. This conversion yields in all cases more than 85% of the mixture. The ratio between the two isomers ranges from 51/49 to 82/18 depending on the rest R (alkyl, aryl or alkoxy substituent). After separation of the two isomers the (E) …
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Modular asymmetric synthesis of functionalized azaspirocycles based on the sulfoximine auxiliary
… was achieved in three steps from cyclic allylic sulfoximines. The first key step was a titanium-mediated gamma-hydroxyalkylation of named sulfoximines. In the course of this reaction two new stereogenic centers and a double bond were created diastereoselectively. The key step for installation of …
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Methodology for the syntheses of pharmaceutically significant functional groups
… polar functional groups such as fluorides or sulfoximines, and stereoisomers that are vital to their bioactivity. As a result, new methods to synthesize these important functional groups are continually in demand. Three main methods to synthesize common pharmacophores are discussed herein: the …
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Struktur, Hydroxyalkylierung und Aminoalkylierung von Titanaallylsulfoximinen: Enantioselektive Synthese ungesättigter Alpha-Aminosäuren
… and Aminoalkylation of Titanaallylsulfoximines: Enantioselective Synthesis of Unsaturated alpha-Amino Acids Enantiopure E- and Z-allylic sulfoximines were lithiated and transmetallated with ClxTi(OR)4-x to give bis(2-alkenyl)titanium(IV)-complexes. These complexes reacted regio- und …
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