Catalytic Asymmetric Oxidation Of Sulfides Research Articles

Catalytic asymmetric oxidation of sulfides to sulfoxides using (R)-6,6$$^{\prime }$$-Diphenyl-BINOL as a chiral ligand

The chiral metal complex produced in situ from (R)-6,6 $$^{\prime }$$ -Diphenyl-BINOL and $$\mathrm{Ti}(\mathrm{O}-{} { i}-\mathrm{Pr})_{4}$$ as a catalytic system for asymmetric sulfoxidation of aryl methyl and aryl benzyl sulfides in the presence of 70% aqueous TBHP as the oxidant has been investigated. The influence of variation of reagents mole ratios, temperature, solvent and oxidant was examined, and the optimized conditions were then used to oxidize a number of aryl methyl and aryl benzyl sulfides, producing sulfoxides in high enantiopurities (up to 90% ee) and good yields (up to 81%). (R)-6,6’-Diphenyl Binol in combination with $$\hbox {Ti(O-i-Pr)}_{4}$$ has been developed as an efficient chiral ligand for the asymmetric oxidation of aryl methyl and aryl benzyl sulfides by using 70% aqueous TBHP as an oxidant. High enantioselectivity and good chemical yield have been achieved for various aryl methyl and aryl benzyl sulfides.

Molybdenum-catalyzed asymmetric sulfoxidation with hydrogen peroxide and subsequent kinetic resolution, using an imidazolium-based dicarboxylate compound as chiral inductor

A catalytic system based on simple and economic molybdenum compounds and a straightforwardly prepared imidazolium-based dicarboxylate compound, as chirality inductor, was developed for the catalytic asymmetric oxidation of sulfides with hydrogen peroxide. High yields of chiral methyl phenyl sulfoxide and good enantioselectivities (up to 40% ee) were achieved utilizing one equivalent of oxidant in 1h. By combination of the enantioselective sulfoxidation and the concomitant kinetic resolution an 83% ee was obtained, an excellent enantioselectivity value for a molybdenum catalyst.

ChemInform Abstract: Synthesis of New Chiral Ligands Based on Thiophene Derivatives for Use in Catalytic Asymmetric Oxidation of Sulfides.

AbstractVanadium complexes of new Schiff base ligands prepared from thiophene derivatives efficiently catalyze the asymmetric oxidation of sulfides by hydrogen peroxide.

Synthesis of New Chiral Ligands Based on Thiophene Derivatives for Use in Catalytic Asymmetric Oxidation of Sulfides

For example, the biological activitiesof sulfoxide containing drugs such as omeprazole arestrongly related to the chirality of the sulfoxide group; forthis reason, esomeprazole, the enantiomerically pure form ofomeprazole, was later developed. There are several chiralsulfoxide based drugs that have been introduced by thepharmaceutical industry including armodafinil, aprikalim,oxisurane, and ustiloxin. Chiral sulfoxides have also beenutilized as chiral auxiliaries in asymmetric syntheses ofchiral intermediates.

Catalytic Asymmetric Oxidation of Heteroaromatic Sulfides with tert‐Butyl Hydroperoxide Catalyzed by a Titanium Complex with a New Chiral 1,2‐Diphenylethane‐1,2‐diol Ligand

AbstractHeteroaromatic sulfoxides, especially 1H‐benzimidazolylpyridinylmethyl sulfoxides, usually used as the blockbuster gastric proton pump inhibitors (PPIs), have been prepared highly enantioselectivily by catalytic asymmetric oxidation of sulfides attached to nitrogen‐containing heterocyles with tert‐butyl hydroperoxide in the presence of a chiral titanium complex, formed in situ from Ti(iPrO)4, chiral 1,2‐diphenylethane‐1,2‐diol 3c and water. The chiral sufoxides were obtained in high yield (97 %) with excellent enantiomeric excess (up to 98 %). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Catalytic enantioselective oxidation of sulfides and disulfides by a chiral complex of bis-hydroxamic acid and molybdenum

A chiral bis-hydroxamic acid (BHA)-molybdenum complex was used for the catalytic asymmetric oxidation of sulfides and disulfides utilizing one equivalent of alkyl peroxide with yields up to 83% and ee up to 86%. An extension of our methodology combines the asymmetric oxidation with kinetic resolution providing excellent enantioselectivity (ee 92–99%).

ChemInform Abstract: Catalytic Asymmetric Oxidation of Sulfides Mediated by a Series of Novel Oxazolines—Titanium Complexes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Novel catalytic asymmetric sulfoxidation in water using the hypervalent iodine reagent iodoxybenzene.

A new catalytic asymmetric oxidation of sulfides to sulfoxides in water using the hypervalent iodine(V) reagent iodoxybenzene (PhIO2) has been developed. This methodology is distinctly different from the previously reported use of cyclodextrins or biological catalysts and provides a new route to asymmetric sulfoxidation in water.

Hypervalent Iodine(V)-Induced Asymmetric Oxidation of Sulfides to Sulfoxides Mediated by Reversed Micelles: Novel Nonmetallic Catalytic System.

Although several types of chiral hypervalent iodine reagents have been used for asymmetric induction, all of them have needed more than a stoichiometric amount of chiral reagents and have shown low enantioselectivities. The described new catalytic asymmetric oxidation using a hypervalent iodine(V) reagent, iodoxybenzene (PhIO(2)), in a cationic reversed micellar system provides the first example of a catalytic asymmetric oxidation of sulfides to sulfoxides in high chemical yield with moderate to good enantioselectivity without the use of any transition-metal catalysts. The solubilization and activation of PhIO(2) by adding catalytic amounts of both cetyltrimethylammonium bromide (CTAB) and a chiral tartaric acid derivative were found to be indispensable for the enhancement of chemical and optical yields.

(S,S)-4,4′-Bis(3-hydroxy-estra-1,3,5(10),6,8-pentaene): An Efficient Ligand for the Catalytic Asymmetric Oxidation of Sulfides to Sulfoxides

(<i>S</i>,<i>S</i>)-4,4′-Bis(3-hydroxy-estra-1,3,5(10),6,8-pentaene): An Efficient Ligand for the Catalytic Asymmetric Oxidation of Sulfides to Sulfoxides

Highly enantioselective catalytic oxidation of alkyl aryl sulfides using Mn-salen catalyst

Catalytic asymmetric oxidation of sulfides was carried out by using Mn-salen complex (aS,R)-4a as a catalyst and high enantioselectivity up to 94% was achieved. Enantioselectivity of the reaction was affected by the solvent used and the use of acetonitrile, ethyl propionate, or chlorobenzene generally gave good results.

ChemInform Abstract: Catalytic Asymmetric Oxidation of Sulfides with High Enantioselectivities.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Catalytic Asymmetric Oxidation of Sulfides With High Enantioselectivities

A new catalytic asymmetric oxidation of various sulfides by cumyl hydroperoxide using a chiral titanium complex as catalyst is reported. Sulfoxides are obtained with enantioselectivities up to 95%.

ChemInform Abstract: Highly Enantioselective Catalytic Asymmetric Oxidation of Sulfides Using Hydrogen Peroxide.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Highly Enantioselective Catalytic Asymmetric Oxidation of Sulfides using Hydrogen Peroxide

Highly Enantioselective Catalytic Asymmetric Oxidation of Sulfides using Hydrogen Peroxide

ChemInform Abstract: A New System for Catalytic Asymmetric Oxidation of Sulfides Using a Hydrogen Peroxide Based Reagent.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Catalytic Asymmetric Oxidation of Sulfides Using (Salen)manganese(III) Complex as a Catalyst.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A new system for catalytic asymmetric oxidation of sulfides using a hydrogen peroxide based reagent

Catalytic asymmetric oxidation of sulfides is achieved in a remarkably simple process by treatment with hydrogen peroxide and an enantiomerically pure sulfonylimine under basic conditions.

Catalytic asymmetric oxidation of sulfides using (salen)manganese(III) complex as a catalyst

Asymmetric oxidation of sulfides was examined by using (salen)manganese(III) complexes as catalysts and (8 S,8′ S,1″ S,2″ S)-complex

ChemInform Abstract: Catalytic Asymmetric Oxidation of Sulfides to Sulfoxides with tert‐ Butyl Hydroperoxide Using Binaphthol as a Chiral Auxiliary.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.