56454-34-3

Upstream product

• 701-57-5 1-methylthio-4-nitro-benzene 
• 940-12-5 p-nitrophenyl methyl sulfoxide 
• 55962-05-5 [N-(p-tolylsulfonyl)imino]phenyliodinane 
• 164021-74-3 (1S,2R)-(-)-2-[N-(3’,5’-di-tert-butylsalicylidene)amino]-1,2-diphenylethanol 
• 75-16-1 methylmagnesium bromide 

Downstream Products

• 125761-96-8 (R)-(+)-Methyl <(4-nitrophenyl)sulfinyl>acetate 

Relevant academic research and scientific papers

Nb(salen)-catalyzed sulfoxidation

Niobium(salen) complex was found to be an effective catalyst for asymmetric oxidation of various sulfides using urea-hydrogen peroxide as terminal oxidant.

Chiral Ligands in Hypervalent Iodine Compounds: Synthesis and Structures of Binaphthyl-Based λ3-Iodanes

Several novel binaphthyl-based chiral hypervalent iodine(III) reagents have been prepared and structurally analysed. Various asymmetric oxidative reactions were applied to evaluate the reactivities and stereoselectivities of those reagents. Moderate to excellent yields were observed; however, very low stereoselectivities were obtained. NMR experiments indicated that these reagents are very easily hydrolysed in either chloroform or DMSO solvents leading to the limited stereoselectivities. It is concluded that the use of chiral ligands is an unsuccessful way to prepare efficient stereoselective iodine(III) reagents.

Diastereoselective oxidation of menthyl arenesulfenates to sulfinates and access to enantioenriched aryl methyl sulfoxides

Three aryl methyl sulfoxides were prepared via the following sequence: synthesis of the menthyl arenesulfenate from the corresponding thiol, diastereoselective oxidation leading to the sulfinate, then reaction with a Grignard reagent. The aryl moiety was substituted with a methyl ester on the ortho position or a nitro group on the ortho or the para position. The sulfenate esters were obtained in fair to excellent yield (42–82%). Four different oxidizing agents were tested to obtain the corresponding sulfinate esters with diastereomeric excesses (de) ranging from 10 to 48%. After separation of the diastereomers and reaction with methyl Grignard reagent, two enantiopure sulfoxides and one enantioenriched sulfoxide (32% ee) were obtained.

Chiral: N, N ′-dioxide-iron(iii)-catalyzed asymmetric sulfoxidation with hydrogen peroxide

A highly enantioselective sulfoxidation of various sulfides has been achieved by a N,N′-dioxide-iron(iii) complex with 35% aq. H2O2 as the oxidant. The utility of the current method was demonstrated by asymmetric gram-scale synthesis of drug molecule (R)-modafinil. Moreover, a possible working mode was provided to elucidate the chiral induction.

An efficient silica supported Chitosan@vanadium catalyst for asymmetric sulfoxidation and its application in the synthesis of esomeprazole

A new type of silica supported Chitosan@vanadium complex was used as a highly active heterogeneous catalyst for asymmetric oxidation of aryl alkyl sulfides. With the economic aqueous H2O2(30%) as the oxidant, the oxidation products were obtained in high yields (up to 95%) with good enantioselectivities (up to 68% ee). It is noted that the marketed drug Nexium (first proton-pump inhibitor, esomeprazole) could be synthesized easily by the newly developed asymmetric sulfoxidation reaction. In addition, the highly active catalyst can be reused five times without losing its catalytic activity.

Bio-inspired single-chain polymeric nanoparticles containing a chiral salen TiIV complex for highly enantioselective sulfoxidation in water

A series of bio-inspired single-chain polymeric nanoparticles (SCPNs) containing a chiral salen TiIV complex in their hydrophobic cavity were constructed from the synthesized amphiphilic copolymers of poly(NIPAAm-co-IL/Ti(salen)) (NIPAAm, N-isopropylacrylamide; IL/Ti(salen), vinylimidazolium ionic liquid-modified chiral salen TiIV complex). These SCPNs behaved as enzyme-mimetic catalysts due to compartmentalization and site isolation, mediating enantioselective oxidation of various sulfides in water with excellent yields (90-99%) and enantioselectivities (ee, 88-99%). In particular, the ee values observed for electron-rich substrates (>95% ee) represented the best results so far in titanium-salen systems. Moreover, the catalysts could be easily recovered for steady reuse by thermo-controlled separation due to thermo-responsive properties. This work first constructed titanium-containing biomimetic SCNPs for biocatalysis of enantioselective sulfoxidation in water.

Cooperative chiral salen TiIV catalyst supported on ionic liquid-functionalized graphene oxide accelerates asymmetric sulfoxidation in water

A cooperative chiral salen TiIV catalyst was prepared by covalently appending multiple chiral salen TiIV complexes on a graphene oxide (GO) surface through a flexible ionic liquid (IL) linker. Characterization results confirmed the decoration of intact Ti(salen) units on the edges and planes of exfoliated GO with the imidazolium-IL spacer. The IL-functionalized GO nanosheets endowed the chiral salen TiIV catalyst with high water-dispersion, diminished diffusion limitation, and particularly a reinforced intramolecular cooperative effect. The cooperative catalyst was thus highly efficient and universally applicable in the catalysis of asymmetric sulfoxidation in water, affording high yields of various chiral sulfoxides with excellent enantioselectivities, while traditional chiral salen TiIV complex was far less active. More importantly, the heterogeneous catalyst was perfectly stable and could be reused several times without significant loss of activity and selectivity.

Method for catalyzing asymmetric oxidation of sulfur ether

The invention provides a method for asymmetrically oxidizing sulfur ether. The sulfur ether is subjected to asymmetric catalytic oxidation reaction by taking a chiral complex formed by a four-tooth nitrogen organic ligand and a metal scandium compound as a catalyst and taking hydrogen peroxide as an oxidizing agent to obtain a corresponding chiral sulfoxide compound, and the yield and the enantioselectivity are more than 90 percent. The reaction has the advantages of cleanness, mild reaction condition, high conversion rate and high enantioselectivity. The method has an industrial prospect.

HPLC enantioseparation on a homochiral MOF-silica composite as a novel chiral stationary phase

The last frontier in the development of chiral stationary phases for chromatographic enantioseparation involves homochiral metal-organic frameworks (MOFs). Using enantiopure (R)-2,2′-dihydroxy-1,1′-binaphthalene-6,6′-dicarboxylic acid as a starting material, we prepared three homochiral MOFs that were further used as chiral stationary phases for high-performance liquid chromatography to separate the enantiomers of various kinds of racemic sulfoxides, sec-alcohols, β-lactams, benzoins, flavanones and epoxides. The experimental results showed excellent performances for enantioseparation, and highlighted that enantioseparation on homochiral MOF columns is practical.

Efficient HPLC enantiomer separation using a pillared homochiral metal-organic framework as a novel chiral stationary phase

HPLC enantioseparation of racemates using novel pillared homochiral metal-organic framework-silica composite as chiral stationary phase has been successfully demonstrated.