24347-61-3

Upstream product

• 917-64-6 methyl magnesium iodide 
• 20698-91-3 (R)-methyl mandelate 
• 768-49-0 (2-methyl-1-propenyl)-benzene 
• 74-88-4 methyl iodide 
• 103729-80-2 2-methyl-1-phenylprop-2-en-1-ol 
• 1251553-88-4 3-((R)-2-hydroxy-2-methyl-1-phenylpropoxy)-3-methoxypropan-1-ol 
• 676-58-4 methylmagnesium chloride 
• 1507-88-6 <(E)-3-chloro-2-methyl-1-propenyl>benzene 
• 165679-83-4 (1R,2S)-1-phenyl-2-methyl-2,3-epoxypropyl acetate 
• 611-71-2 (R)-Mandelic Acid 

Relevant academic research and scientific papers

Production Of Enantiopure alpha-Hydroxy Carboxylic Acids From Alkenes By Cascade Biocatalysis

The invention provides compositions comprising an alkene epoxidase and a selective epoxide hydrolase, such as a recombinant microorganism comprising a first heterologous nucleic acid encoding an alkene epoxidase and a second heterologous nucleic acid encoding a selective epoxide hydrolase. Exemplary alkene epoxidases include StyAB, while exemplary selective epoxide hydrolases include epoxide hydrolases from Sphingomonas, Solanum tuberosum, or Aspergillus. The invention also provides non-toxic methods of making enantiomerically pure vicinal diols or enantiomerically pure alpha-hydroxy carboxylic acids using these compositions and microorganisms.

AMIDO THIADIAZOLE DERIVATIVES AS NADPH OXIDASE INHIBITORS

The present invention is related to amino thiazole derivatives of Formula (I), pharmaceutical composition thereof and to their use for the treatment and/or prophylaxis of disorders or conditions related to Nicotinamide adenine dinucleotide phosphate oxidase (NADPH Oxidase).

Ionophilic imidazolium-tagged cinchona ligand on LDH-immobilized osmium: Recyclable and recoverable catalytic system for asymmetric dihydroxylation reaction of olefins

Abstract A catalytic system for the asymmetric dihydroxylation of olefins was developed by using an ionic-tagged biscinchona alkaloid ligand immobilized onto OsO4-exchanged layered double hydroxide (LDH) as a robust recyclable homogenous-heterogeneous catalytic system. The desired products were obtained in high yield and enantioselectivity.

Enantioselective trans-dihydroxylation of aryl olefins by cascade biocatalysis with recombinant escherichia coli coexpressing monooxygenase and epoxide hydrolase

Cascade biocatalysis via intracellular epoxidation and hydrolysis was developed as a green and efficient method for enantioselective dihydroxylation of aryl olefins to prepare chiral vicinal diols in high ee and high yield. Escherichia coli (SSP1) coexpressing styrene monooxygenase (SMO) and epoxide hydrolase SpEH was developed as a simple and efficient biocatalyst for S-enantioselective dihydroxylation of terminal aryl olefins 1a-15a to give (S)-vicinal diols 1c-15c in high ee (97.5-98.6% for 10 diols; 92.2-93.9% for 3 diols) and high yield (91-99% for 6 diols; 86-88% for 2 diols; 67% for 3 diols). Combining SMO and epoxide hydrolase StEH showing complementary regioselectivity to SpEH as a biocatalyst for the cascade biocatalysis gave rise to R-enantioselective dihydroxylation of aryl olefins, being the first example of this kind of reversing the overall enantioselectivity of cascade biocatalysis. E. coli (SST1) coexpressing SMO and StEH was also engineered as a green and efficient biocatalyst for R-dihydroxylation of terminal aryl olefins 1a-15a to give (R)-vicinal diols 1c-15c in high ee (94.2-98.2% for 7 diols; 84.2-89.9% for 6 diols) and high yield (90-99% for 6 diols; 85-89% for 5 diols; 65% for 1 diol). E. coli (SSP1) and E. coli (SST1) catalyzed the trans-dihydroxylation of trans-aryl olefin 16a and cis-aryl olefin 17a with excellent and complementary stereoselectivity, giving each of the four stereoisomers of 1-phenyl-1,2- propanediol 16c in high ee and de, respectively. Both strains catalyzed the trans-dihydroxylation of aryl cyclic olefins 18a and 19a to afford the same trans-cyclic diols (1R,2R)-18c and (1R,2R)-19c, respectively, in excellent ee and de. This type of cascade biocatalysis provides a tool that is complementary to Sharpless dihydroxylation, accepting cis-alkene and offering enantioselective trans-dihydroxylation.

A recyclable dendritic osmium catalyst for homogeneous dihydroxylation of olefins

A series of osmate (OsO42-) core dendrimers was prepared by an ion-exchange technique through the mixing of K 2OsO4 and a bis(quaternary ammonium bromide) core dendrimer, which consisted of poly(benzyl ether) dendron. By employing an osmate core dendrimer as a homogeneous catalyst, dihydroxylation reactions of olefins proceeded rapidly, and the dendritic osmium catalyst was recovered by reprecipitation and then reused. Furthermore, a dendritic effect on the recyclability of a catalyst was observed. In the case of asymmetric dihydroxylation reactions, the corresponding diol was obtained in a high chemical yield with a fair enantiomeric excess (ee). In this case, not only the dendritic osmium catalyst but also the chiral ligand could be recovered by reprecipitation and reused efficiently up to five times.

Asymmetric synthesis of 2,3-dihydro-4-pyranones by reaction of chiral 3-alkoxycyclobutanone and aldehydes

Chiral cyclobutanone which had ethyl l-lactate as a chiral auxiliary at the 3-position reacted with aldehydes to give 2,3-dihydro-4-pyranones in up to 93% ee by combined use of titanium(IV) chloride and tin(II) chloride.

Preparation, characterization and catalytic properties of polyaniline-supported metal complexes

Polyaniline-supported Sc, In, Pd, Os and Re catalysts were prepared by using a simple protocol and the thus prepared catalysts were well characterized using FTIR, XPS, UV-Vis/DRS, TGA-DTA. All the catalysts were successfully employed in a wide range of organic transformations such as cyanation and allylation of carbonyl compound, Suzuki coupling of aryl halides and boronic acids, and, most importantly, in asymmetric dihydroxylation of olefins to afford optically active vicinal diols. All the catalysts were separated from the reaction mixture by simple filtration and reused with consistent activity for five cycles without noticeable leaching of metal from the support.

A trifunctional catalyst for one-pot synthesis of chiral diols via heck coupling-N-oxidation-asymmetric dihydroxylation: Application for the synthesis of diltiazem and taxol side chain

A heterogeneous bifunctional catalyst composed of OsO42--WO42- and a trifunctional catalyst comprising PdCl42--OsO42-- WO42-, designed and prepared by an ion-exchange technique using layered double hydroxides (LDH) as an ion-exchanger and their homogeneous bifunctional analogue, K2OsO4-Na2WO4 and trifunctional analogue, Na2PdCl4-K2OsO4-K2 OSO4-NNa2WO4, devised for the first time are evaluated for the synthesis of chiral vicinal diols. These bifunctional and trifunctional catalysts perform asymmetric dihydroxylation-N-oxidation and Heck-asymmetric dihydroxylation-N-oxidation, respectively, in the presence of Sharpless chiral ligand, (DHQD)2PHAL in a single pot using H2O2 as a terminal oxidant to provide N-methylmorpholine oxide (NMO) in situ by the oxidation of N-methylmorpholine (NMM). The heterogeneous bifunctional catalyst supported on LDH (LDH-OsW) displays superior activity to afford diols with higher yields over the other heterogeneous catalysts developed by the ion exchange on quaternary ammonium salts covalently bound to resin (resin-OsW) and silica (silica-OsW) or homogeneous catalysts in the achiral dihydroxylation reactions. The LDH-OsW and its homogeneous analogue are found to be very efficient in performing a simultaneous asymmetric dihydroxylation (AD)-N-oxidation of a wide and varied range of aromatic, cyclic, and mono, di-, and trisubstituted olefins to obtain chiral vicinal diols with higher yields and ee's using H2O2. Further, the use of OsO42--WO42-- WO42- catalysts as such or in the supported form offers a simplified procedure for catalyst recycling, which shows consistent activity for a number of cycles. In this process, OsVI is recycled to OsVIII by a coupled electron transfer-mediator (ETM) system based on NMO-WO42- using H2O2, leading to a mild and selective electron transfer. The one-pot biomimic synthesis of chiral diols is mediated by a recyclable trifunctional heterogeneous catalyst (LDH-PdOsW) consisting of active palladium, tungsten, and osmium species embedded in a single matrix. This protocol, which provides prochiral olefins and NMO in situ by Heck coupling and N-oxidation of NMM, respectively, required for the AD, unfolds a low cost process. We extended the present method to the one-pot synthesis of trisubstituted chiral vicinal diols with moderate to excellent ee's by AD of trisubstituted olefins that are obtained by in situ Heck arylation of disubstituted olefins. The heterogeneous trifunctional catalysts offers chiral diols with unprecedented ee's and excellent yields in the AD of prochiral cinnamates, which are obtained in situ from acrylates and halobenzenes for the first time. The new variants such as LDH support and Et3N·HX inherently composed in the heterogeneous multicomponent system and slow addition of H202 facilitates the hydrolysis of osmium monogylcolate ester to subdue the formation of bisglycolate ester to achieve higher ee's. Without resorting to recrystallization, the chiral diols of cinnamates thus synthesized with 99% ee's and devoid of osmium contamination are directly put to use in the synthesis of diltiazem and Taxol side chain with an overall improved yield to demonstrate the synthetic utility of the trifunctional heterogeneous catalyst. The high binding ability of the heterogeneous osmium catalyst enables the use of equimolar ratio of ligand to osmium to give excellent ee's in AD in contrast to the homogeneous osmium system in which the excess molar quantities of the expensive chiral ligand to osmium are invariably used. Further, the XRD, FT-IR, UV-vis DRS, and XPS studies indicate the retention of the coordination geometries of the specific divalent anions anchored to LDH matrix in their monomeric form during the ion exchange and after the reaction.

The synthesis of the anti-malarial natural product polysphorin and analogues using polymer-supported reagents and scavengers.

A general asymmetric route to both enantiomers of polysphorin has been developed. The route utilizes polymer-supported reagents, catalysts and scavengers to minimise the need for aqueous work-up and chromatography. This includes application of a method to scavenge 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and a "catch-and-release" procedure to extract the resultant diol following Sharpless asymmetric dihydroxylation. A novel enzymatic selective protection and investigations of a new asymmetric dihydroxylation using microencapsulated osmium tetroxide were also investigated during the course of this study.

Catalytic asymmetric dihydroxylation of olefins with reusable OsO42- on ion-exchangers: The scope and reactivity using various cooxidants

Exchanger-OsO4 catalysts are prepared by an ion-exchange technique using layered double hydroxides and quaternary ammonium salts covalently bound to resin and silica as ion-exchangers. The ion-exchangers with different characteristics and opposite ion selectivities are specially chosen to produce the best heterogeneous catalyst that can operate using the various cooxidants in the asymmetric dihydroxylation reaction. LDH-OsO4 catalysts composed of different compositions are evaluated for the asymmetric dihydroxylation of trans-stilbene. Resin-OsO4 and SiO2-OsO4 designed to overcome the problems associated with LDH-OsO4 indeed show consistent activity and enantioselectivity in asymmetric dihydroxylation of olefins using K3Fe(CN)6 and molecular oxygen as cooxidants. Compared to the Kobayashi heterogeneous systems, resin-OsO4 is a very efficient catalyst for the dihydroxylation of a wide variety of aromatic, aliphatic, acyclic, cyclic, mono-, di-, and trisubstituted olefins to afford chiral vicinal diols with high yields and enantioselectivities irrespective of the cooxidant used. Resin-OsO4 is recovered quantitatively by a simple filtration and reused for a number of cycles with consistent activity. The high binding ability of the heterogeneous osmium catalyst enables the use of an equimolar ratio of ligand to osmium to give excellent enantioselectives in asymmetric dihydroxylation in contrast to the homogeneous osmium system in which excess molar quantities of the expensive chiral ligand to osmium are invariably used. The complexation of the chiral ligand (DHQD)2PHAL, having very large dimension, a prerequisite to obtain higher ee, is possible only with the OsO42- located on the surface of the supports.