Category: chiral-phosphine-ligands

James, Jinju; Guiry, Patrick J. published the artcile< Highly Enantioselective Construction of Sterically Hindered α-Allyl-α-Aryl Lactones via Palladium-Catalyzed Decarboxylative Asymmetric Allylic Alkylation>, Electric Literature of 152140-65-3, the main research area is enantioselective preparation allyl aryl lactone; palladium catalyst decarboxylative asym allylic alkylation.

Pd-catalyzed decarboxylative asym. allylic alkylation has been developed for sterically hindered α-aryl, β-oxoallyl ester lactone substrates. Pb-mediated α-arylation of the β-oxoallyl ester was used as the key step to synthesize the substrates for catalysis in moderate to high yields. Optimization studies for decarboxylative asym. allylic alkylations (DAAA) were conducted using δ-valerolactone-derived α-aryl β-oxoallyl ester with 2,4,6-trimethoxyphenyl as the aryl substituent. Using (R,R)-ANDEN-Ph Trost as the chiral ligand, enantioselectivities of up to >99% ee and 98% ee were achieved with the six-membered and five-membered lactone substrates, resp. Bulky aryl groups containing di-ortho substitutions and naphthyl groups gave the highest enantioselectivities. This synthetic route allows for the simple modification of aryl groups, giving highly enantioselective access to important structural motifs.

ACS Catalysis published new progress about Allylic alkylation. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Electric Literature of 152140-65-3.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Mullen, Charles A.; Campbell, Alison N.; Gagne, Michel R. published the artcile< Asymmetric oxidative cation/olefin cyclization of polyenes: evidence for reversible cascade cyclization>, SDS of cas: 325168-88-5, the main research area is polyenol xylylphanephos platinum silver enantioselectively diastereoselectively regioselectively oxidative cyclization; fused oxygen containing heterocycle stereoselective preparation reaction determining step.

Activation of [(xylyl-phanephos)PtCl2] by silver generates an electrophilic catalyst that can enantioselectively, diastereoselectively, and regioselectively promote the stereospecific oxidative cyclization of polyene-ols. Mechanistic experiments indicate that the stereochem.-determining step is not the initial cyclization step, but rather a subsequent step in the reaction.

Angewandte Chemie, International Edition published new progress about Alkenyl alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, SDS of cas: 325168-88-5.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Shintani, Ryo; Duan, Wei-Liang; Hayashi, Tamio published the artcile< Rhodium-Catalyzed Asymmetric Construction of Quaternary Carbon Stereocenters: Ligand-Dependent Regiocontrol in the 1,4-Addition to Substituted Maleimides>, Reference of 139139-86-9, the main research area is rhodium complex asym addition reaction regioselectivity enantioselectivity; arylboronic acid maleimide asym addition reaction.

A rhodium-catalyzed asym. 1,4-addition of arylboronic acids of formula ArB(OH)2 (Ar = Ph, 2-naphthyl, 2-methylphenyl, 4-methoxyphenyl, 4-fluorophenyl) to substituted maleimides (I; R = Et, Me, i-Pr) has been described. The regioselectivity in this reaction is controlled by the choice of ligand (dienes or bisphosphines), and 1,4-adducts with a quaternary stereocenter (II; Ar, R = same as above) can be obtained with high regio- and enantioselectivity over 1,4-adducts with a secondary carbon center (III; Ar, R = same as above) by the use of (R)-H8-BINAP (IV). For example, I (R = Et), 3.0 equiv phenylboronic acid, 2.5 mol% divinylrhodium chloride dimer, IV (Rh/ligand = 1:1), and 0.5 equiv KOH were stirred in a 10:1 mixture of dioxane and water at 50° for 3 h to give a 87:13 mixture of II (Ar = Ph, R = Et) and III (Ar = Ph, R = Et) in 98% yield.

Journal of the American Chemical Society published new progress about Boronic acids Role: RCT (Reactant), RACT (Reactant or Reagent) (arylboronic acids). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Reference of 139139-86-9.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Yang, Jing; Wang, Kunqi; Liang, Liang; Feng, Ligang; Zhang, Yuwei; Sun, Bo; Xing, Wei published the artcile< A hybrid photoelectrochemical biofuel cell based on the photosensitization of a chlorophyll derivative on TiO2 film>, Reference of 606-68-8, the main research area is hybrid photoelectrochem biofuel cell photosensitization chlorophyll derivative titania film.

A hybrid photoelectrochem. biofuel cell is composed of a TiO2 film conductive glass electrode sensitized by a copper chlorophyll trisodium salt in combination with the platinized cathode and the electrolyte which contains redox mediator and enzyme as catalyst. The photovoltaic measurements indicate the optimal dye-adsorption time is 4 h and the incident photon-to-collected electron conversion efficiency is 16% at 400 nm. From the current-voltage curve the open-circuit voltage, short-circuit c.d., maximum power d. and overall energy conversion efficiency are 468 mV, 482 μA/cm2, 97 μW/cm2 and 9.7%, resp.

Catalysis Communications published new progress about Biochemical fuel cells (hybrid photoelectrochem.). 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Reference of 606-68-8.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Ishii, Masahiro; Mori, Fumiya; Tanaka, Ken published the artcile< Rhodium-Catalyzed [2+2+2] Cycloaddition of Diynes with Carbodiimides and Carbon Dioxide under Ambient Conditions>, COA of Formula: C44H40P2, the main research area is rhodium cycloaddition diyne carbodiimide carbon dioxide; carbodiimides; carbon dioxide; cycloaddition; diynes; rhodium.

It was established that a cationic rhodium(I)/H8-BINAP complex is able to catalyze a [2+2+2] cycloaddition of diynes with carbodiimides and carbon dioxide under ambient conditions. Enantioselective variants and regioselective variants of these reactions are also disclosed. Under optimized conditions the synthesis of the target compounds was achieved using N,N’-[(methane)tetrayl]bis[4-methylbenzenamine], N,N’-[(methane)tetrayl]bis[cyclohexanamine] (i.e., dicyclohexylcarbodiimide) and diynes, such as 2,2-bis(2-propynyl)propanedioic acid esters, 4-methyl-N,N-bis(2-propynyl)benzenesulfonamide. 3,3-bis(2-butynyl)-2,4-pentanedione as starting materials, bis[(1,2,5,6-η)-1,5-cyclooctadiene]rhodium tetrafluoroborate(1-) as a catalyst and 1,1′-(5,5′,6,6′,7,7′,8,8′-octahydro[1,1′-binaphthalene]-2,2′-diyl)bis[1,1-diphenylphosphine] (H8-BINAP) as a ligand.

Chemistry – A European Journal published new progress about Alkadiynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, COA of Formula: C44H40P2.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Trost, Barry M.; Xie, Jia published the artcile< Palladium-Catalyzed Diastereo- and Enantioselective Wagner-Meerwein Shift: Control of Absolute Stereochemistry in the C-C Bond Migration Event>, Related Products of 152140-65-3, the main research area is palladium catalyzed Wagner Meerwein ring expansion diastereoselective enantioselective; cyclopentanone derivative diastereoselective enantioselective synthesis.

Inducing absolute stereochem. in Wagner-Meerwein shifts was examined in a ring expansion protocol. Initiated by generation of a π-allylpalladium intermediate by hydropalladation of allenes, the ring expansion of allenylcyclobutanol substrates proceeded with excellent diastereo- and enantioselectivities. The results demonstrate that, during the C-C bond migration process, our chiral catalysts can control the stereochem. of both the π-allylpalladium intermediate and the corresponding migration bond. Moreover, the stereochem. outcome of the reaction can be rationalized very well with the working model of the chiral catalyst. The method provides an efficient way to synthesize highly substituted cyclopentanones with an α-chiral O-tertiary center which has various synthetic applications.

Journal of the American Chemical Society published new progress about Absolute configuration (of ring expansion products). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Related Products of 152140-65-3.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Trost, Barry M.; Xu, Jiayi; Reichle, Markus published the artcile< Enantioselective Synthesis of α-Tertiary Hydroxyaldehydes by Palladium-Catalyzed Asymmetric Allylic Alkylation of Enolates>, Quality Control of 152140-65-3, the main research area is tertiary hydroxy aldehyde enantioselective preparation; enolate asym allylic alkylation palladium catalysis; oxybutynin formal synthesis synthon.

Chiral α-tertiary hydroxyaldehydes are very versatile building blocks in synthetic chem. A catalytic asym. synthesis of α-tertiary hydroxyaldehydes, e.g. I, via palladium-catalyzed asym. allylic alkylation of siloxy enol carbonates, e.g. II and III, with excellent yields and enantioselectivity, is reported. Its synthetic utility is demonstrated in the formal synthesis of (S)-oxybutynin. In this process, the chiral ligand controls the regioselectivity as well as the enantioselectivity.

Journal of the American Chemical Society published new progress about Aldehydes, hydroxy Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Quality Control of 152140-65-3.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Rzygalinski, Ignacy; Pobozy, Ewa; Drewnowska, Renata; Trojanowicz, Marek published the artcile< Enzymatic in-capillary derivatization for glucose determination by electrophoresis with spectrophotometric detection>, Electric Literature of 606-68-8, the main research area is glucose oxidation capillary electrophoresis oxidase peroxidase gluconolactone.

The following paper compares several procedures of in-capillary bienzymic derivatization with regard to glucose determination with the use of glucose oxidase and horseradish peroxidase. The procedures discussed below include continuous contact in the capillary, plug-plug injection, and sequential injection with incubation in the capillary inlet. The reaction of hydrogen peroxide catalyzed by peroxidase was performed using two different substrates. The best results were achieved for NAD, reduced disodium salt (NADH) acting both as a chromogenic reagent and a substrate for peroxidase, while the method employed was sequential injection and incubation at the capillary inlet. The LOD was estimated to be 25 nM with a linear response up to 0.1 μM.

Electrophoresis published new progress about Capillary electrophoresis. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Electric Literature of 606-68-8.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Chang, Xin; Ma, Pei-Long; Chen, Hong-Chao; Li, Chuan-Ying; Wang, Peng published the artcile< Asymmetric Synthesis and Application of Chiral Spirosilabiindanes>, Quality Control of 139139-93-8, the main research area is alkenyldihydrosilane preparation rhodium catalyzed asym double hydrosilation spirocyclization; spirosilabiindane chiral preparation reaction aminophosphine; phosphoramidite spirosilabiindane chiral preparation catalyst ligand asym hydrogenation carboamination; crystal structure chiral spirosilabiindane diol derivative phosphoramidite; mol structure chiral spirosilabiindane diol derivative phosphoramidite; asymmetric catalysis; ligand design; silanes; spirocompounds; synthetic methods.

Reported here is the development of a class of chiral spirosilabiindane scaffolds by Rh-catalyzed asym. double hydrosilation, for the 1st time. Enantiopure SPSiOL (spirosilabiindane diol), a new type of chiral building block for the preparation of various chiral ligands and catalysts, was readily prepared on >10 g scale using this protocol. The potential of this new spirosilabiindane scaffold in asym. catalysis was preliminarily demonstrated by development of the corresponding monodentate phosphoramidite ligands (SPSiPhos), which were used in both a Rh-catalyzed hydrogenation and a Pd-catalyzed intramol. carboamination.

Angewandte Chemie, International Edition published new progress about Alkenes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation) (bis(alkenyl)dihydrosilanes). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Quality Control of 139139-93-8.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Ostrakhovitch, Elena A.; Song, Eun-Suk; Macedo, Jessica K. A.; Gentry, Matthew S.; Quintero, Jorge E.; van Horne, Craig; Yamasaki, Tritia R. published the artcile< Analysis of circulating metabolites to differentiate Parkinson′s disease and essential tremor>, Application of C21H27N7Na2O14P2, the main research area is metabolites differentiate Parkinson disease essential tremor; Alpha-synuclein; Cerebrospinal fluid; Metabolomic analysis; Parkinson’s disease; Plasma.

Parkinson′s disease (PD) and essential tremor (ET) are two common adult-onset tremor disorders in which prevalence increases with age. PD is a neurodegenerative condition with progressive disability. In ET, neurodegeneration is not an established etiol. We sought to determine whether an underlying metabolic pattern may differentiate ET from PD. Circulating metabolites in plasma and cerebrospinal fluid (CSF) were analyzed using gas chromatog.-mass spectroscopy. There were several disrupted pathways in PD compared to ET plasma including glycolysis, tyrosine, phenylalanine, tyrosine biosynthesis, purine and glutathione metabolism Elevated α-synuclein levels in plasma and CSF distinguished PD from ET. The perturbed metabolic state in PD was associated with imbalance in the pentose phosphate pathway, deficits in energy production, and change in NADPH, NADH and nicotinamide phosphoribosyltransferase levels. This work demonstrates significant metabolic differences in plasma and CSF of PD and ET patients.

Neuroscience Letters published new progress about Cerebrospinal fluid. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Application of C21H27N7Na2O14P2.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate