Search results for "Sulfoxide"
showing 10 items of 313 documents
Inhibitoren der Korrosion 23 (1) - Gibt es eine Struktur- Wirkungs-Beziehung bei organischen Inhibitoren der Korrosion von Aluminium?
1978
Uber 400 organische Verbindungen wurden routinemasig darauf gepruft, ob sie die Auflosung des Aluminiums in In Salzsaure in Gegenwart von 2,5% NaCl und bei einer Konzentration von 10−2 Mol/l der zu prufenden Verbindung beeinflussen. Es wurde versucht, eine “Struktur-Wirkungs-Beziehung” zu erstellen. Eingehender diskutiert wurden folgende Verbindungsklassen: Arsenverbindungen, Phosphon- und Phosphinsauren, aromatische Aldehyde und Ketone, aromatische und aliphatische Carbonsauren, zweiwertige Phenole, Tetrazoliumsalze und formazane, Sulfoxide und aromatische Sulfonsauren, Sulfonamide und Sulfone. Bei einer Auswahl von Inhibitoren wurde die Abhangigkeit der Schutzwirkung von deren Konzentrati…
Tandem asymmetric Michael reaction-intramolecular Michael addition. An easy entry to chiral fluorinated 1,4-dihydropyridines.
2010
A novel one-pot tandem asymmetric Hantzsch-type process has been employed to generate fluorinated 1,4-dihydropyridines (1,4-DHPs) as single diastereoisomers. It involves the condensation of (R)-(+)-allyl p-tolyl sulfoxide, fluorinated nitriles, and alkyl propiolates, giving access to a new family of enantiomerically pure fluorine-containing 1,4-DHPs.
Palladium-catalyzed reaction of boronic acids with chiral and racemic alpha-bromo sulfoxides.
2004
Palladium-catalyzed cross-coupling reactions of racemic alpha-bromo sulfoxides with boronic acids are carried out in either aqueous or nonaqueous medium with formation of a new C sp(3)-C sp(2) bond. The arylation of chiral alpha-bromo sulfoxides occurs without racemization. The cross-coupling reaction is general and gives high yields with arylboronic acids substituted with either donor or acceptor groups but gives poor results with heteroarylboronic acids. The best yields are obtained using degassed solvents and CsF instead of aqueous base. The use of aqueous base and the presence of oxygen favor the homocoupling side reaction.
Enhanced Skin Permeation of Estradiol by Dimethyl Sulfoxide Containing Transdermal Patches.
2021
Dimethyl sulfoxide is a well-known and widely used dermal penetration enhancer. Its incorporation in transdermal patches would be highly desirable
Mechanism of the Oxidation of Sulfides by Dioxiranes. 1. Intermediacy of a 10-S-4 Hypervalent Sulfur Adduct
2002
Earlier studies established that dimethyldioxirane (1a) reacts with sulfides 2 in two consecutive concerted electrophilic oxygen-transfer steps to give first sulfoxides 3 and then sulfones 4. The same sequential electrophilic oxidation model was assumed for the reaction of sulfides 2 with the strongly electrophilic methyl(trifluoromethyl)dioxirane (1b). In this paper we report on a systematic and general study on the mechanism of the reaction of simple sulfides 2 with DMDO (1a) and TFDO (1b) which provides clear evidence for the involvement of hypervalent sulfur species in the oxidation process. In the oxidation of sulfides 2a-c, diphenyl sulfide (2d), para-substituted aryl methyl sulfides …
Oxidation of Sulfides with a Silica-Supported Peracid in Supercritical Carbon Dioxide under Flow Conditions: Tuning Chemoselectivity with Pressure
2010
Supercritical carbon dioxide is a convenient medium for performing the selective oxidation of sulfides 1 to either sulfoxides 2 or sulfones 3 with [2-percarboxyethyl]-functionalized silica (4) under flow conditions. The chemoselectivity of the reaction, which results from the different diffusion rates of sulfide and sulfoxide over the reagent bed, can be controlled by adjusting the pressure and the hydration of the silica surface as both the solvating power of the mobile phase and the surface activity of the stationary phase determine the migration rates of sulfide 1 and sulfoxide 2 over the supported peroxide. The results elucidate the impact of surface phenomena on the course of chemical …
Pyrrolo[3,4-e][1,2,3]triazolo[1,5-a]pyrimidine and pyrrolo[3,4-d] [1,2,3]triazolo[1,5-a]pyrimidine. New tricyclic ring systems of biological interest
2000
Derivatives of the new ring system pyrrolo[3,4-e][1,2,3] triazolo[1,5-a]pyrimidine 6 were prepared in high yields in one step by reaction of 3-azidopyrrole 3 and substituted acetonitriles. Compound 6b rearranged, upon heating in dimethyl sulfoxide in the presence of water, to pyrrolo[3,4-d][1,2,3]triazolo-[1,5-a]pyrimidine 7.
ChemInform Abstract: Pyrrolo[3,4-e][1,2,3]triazolo[1,5-a]pyrimidine and Pyrrolo[3,4-d][1,2,3]triazolo[1,5-a]pyrimidine. New Tricyclic Ring Systems of…
2001
Derivatives of the new ring system pyrrolo[3,4-e][1,2,3] triazolo[1,5-a]pyrimidine 6 were prepared in high yields in one step by reaction of 3-azidopyrrole 3 and substituted acetonitriles. Compound 6b rearranged, upon heating in dimethyl sulfoxide in the presence of water, to pyrrolo[3,4-d][1,2,3]triazolo-[1,5-a]pyrimidine 7.
ChemInform Abstract: Tandem Asymmetric Michael Reaction-Intramolecular Michael Addition. An Easy Entry to Chiral Fluorinated 1,4-Dihydropyridines.
2010
The sequential treatment of optically active sulfoxide (I) with fluorinated nitriles and alkyl propiolates affords (sulfinylmethyl)dihydropyridines of type (IV) as single diastereomers in most cases.
5,6,7-Trimethoxy-2,3-dihydro-1H,8H-benzo[a]pyrrolo[3,4-c]carbazole-1,3-dione dimethyl sulfoxide solvate
2005
The crystal structure of the title compound, C21H16N2O5·C2H6OS, was determined to investigate the electrocyclic reactivity of 3,4-diaryl-1H-pyrrole-2,5-diones (3,4-bisarylmaleimides) to the yield corresponding carbazole derivatives.