Chiral phosphine ligands

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

Gorbunova, Ioanna A.; Sasin, Maxim E.; Beltukov, Yaroslav M.; Semenov, Alexander A.; Vasyutinskii, Oleg S. published the artcile< Anisotropic relaxation in NADH excited states studied by polarization-modulation pump-probe transient spectroscopy>, Recommanded Product: ((2R,3S,4R,5R)-5-(6-Aminopurin-9-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy-((((2R,3S,4R,5R)-5-(3-carbamoyl-4H-pyridin-1-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy)hydroxyphosphoryl)oxyphosphinic acid disodium salt, the main research area is beta NADH disodium salt excited state dynamics anisotropic relaxation.

We present the results of exptl. and theor. studies of fast anisotropic relaxation and rotational diffusion in the first electron excited state of biol. coenzyme NADH in water-ethanol solutions The experiments have been carried out by means of a novel polarization-modulation transient method and fluorescence polarization spectroscopy. For interpretation of the exptl. results a model of the anisotropic relaxation in terms of scalar and vector properties of transition dipole moments has been developed based on the Born-Oppenheimer approximation This model allows for the description of fast isotropic and anisotropic excited state relaxation under excitation of mols. by ultrafast laser pulses in transient absorption and upconversion experiments The results obtained suggest that the dynamics of anisotropic rovibronic relaxation in NADH under excitation with 100 fs pump laser pulses can be characterised by a single vibrational relaxation time τv lying in the range of 2-15 ps and a single rotation diffusion time τr lying in the range of 100-450 ps, both depending on ethanol concentration The dependence of the times τv and τr on the solution polarity (static permittivity) and viscosity has been determined and analyzed. Limiting values of the term {P2(cos θ)} describing the rotation of the transition dipole moment in the course of vibrational relaxation have been determined from experiments as a function of ethanol concentration and analyzed.

Physical Chemistry Chemical Physics published new progress about Electronic transition dipole moment. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Recommanded Product: ((2R,3S,4R,5R)-5-(6-Aminopurin-9-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy-((((2R,3S,4R,5R)-5-(3-carbamoyl-4H-pyridin-1-yl)-3,4-dihydroxy-oxolan-2-yl)methoxy)hydroxyphosphoryl)oxyphosphinic acid disodium salt.

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

Wilson, Thomas A.; Musameh, Mustafa; Kyratzis, Ilias L.; Zhang, Jie; Bond, Alan M.; Hearn, Milton T. W. published the artcile< Variation of Carbon Based Materials on the Electropolymerization of Tyramine>, Quality Control of 606-68-8, the main research area is carbon electropolymerization tyramine sensor NADH.

The electropolymerization of tyramine was studied using glassy C electrodes modified with six classes of C materials, C black, graphitized C, graphite, graphene oxide, CVD based multi-walled C nanotubes and arc discharged based multi-walled C nanotubes. These materials were characterized before and after electrodeposition of polytyramine (PT) by Raman spectroscopy, inductively coupled plasma optical emission spectrometry, cyclic voltammetry and amperometry. Previously, other groups established that impurities present in C materials, can play a critical role in electrocatalytic activity. The presence of graphitic basal plane C, rather than metallic impurities, is believed to initiate the formation of a redox active PT film that mediates the oxidation of NADH. The importance of graphitic basal plane C was supported by examining the impact of the graphitization of C black at 500-2000°. Graphitic basal plane C impurity is highly active and important with respect to the electrodeposition of a PT film that possesses significant catalytic activity towards the oxidation of NADH.

Electroanalysis published new progress about Amperometry. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Quality Control 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

Tintas, Mihaela-Liliana; Azzouz, Rabah; Peauger, Ludovic; Gembus, Vincent; Petit, Emilie; Bailly, Laetitia; Papamicael, Cyril; Levacher, Vincent published the artcile< Access to Highly Enantioenriched Donepezil-like 1,4-Dihydropyridines as Promising Anti-Alzheimer Prodrug Candidates via Enantioselective Tsuji Allylation and Organocatalytic Aza-Ene-Type Domino Reactions>, SDS of cas: 152140-65-3, the main research area is enantioenriched donepezil dihydropyridine preparation anti Alzheimer activity; enantioselective Tsuji allylation organocatalysis aza ene domino.

This work aims at exploiting both the enantioselective Tsuji allylation of allyl carbonate and an organocatalytic aza-ene-type domino reaction between enal and β-enaminone to develop a straightforward access to all of the four possible stereoisomers of a donepezil-like 1,4-dihydropyridine (er up to 99.5:0.5; overall yield up 64%), an anti-Alzheimer’s prodrug candidate. This strategy was extended to the preparation of other enantioenriched 1,4-dihydropyridines (eight examples), highlighting its potential in the development of these chiral AChE inhibitors.

Journal of Organic Chemistry published new progress about Allylation (Tsuji). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, SDS of cas: 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

Hatano, Manabu; Terada, Masahiro; Mikami, Koichi published the artcile< Highly enantioselective palladium-catalyzed ene-type cyclization of a 1,6-enyne>, Quality Control of 139139-93-8, the main research area is furan vinyl methoxycarbonylmethylidene methyl preparation enantioselective; palladium catalyzed carbocyclization enyne; crystal structure vinylmethylcaboxymethylidenefuran phenylethylamine salt; asymmetric catalysis; cyclizations; enynes; palladium.

The authors developed a highly efficient palladium(II)-catalyzed ene-type carbocyclization of 1,6-enyne MeCH=C(Me)CH2OCH2CCCO2Me leading to enantiopure furan (I). This highly enantioselective catalysis is applicable for the construction of an enantioenriched quaternary chiral center. Possible mechanisms including neutral and cationic intermediate have been proposed.

Angewandte Chemie, International Edition published new progress about Alkenynes Role: RCT (Reactant), RACT (Reactant or Reagent). 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

Wang, Duo-Sheng; Chen, Qing-An; Li, Wei; Yu, Chang-Bin; Zhou, Yong-Gui; Zhang, Xumu published the artcile< Pd-Catalyzed Asymmetric Hydrogenation of Unprotected Indoles Activated by Bronsted Acids>, Formula: C44H40P2, the main research area is indoline asym preparation reaction mechanism; unprotected indole asym hydrogenation palladium catalyst Bronsted acid activator; dynamic kinetic resolution.

The first highly enantioselective hydrogenation of simple indoles was developed with a Bronsted acid as an activator to form the iminium intermediate in situ, which was hydrogenated using Pd(OCOCF3)2/(R)-H8-BINAP catalyst system with up to 96% ee. The present method provides an efficient route to enantioenriched 2-substituted, e.g., I and 2,3-disubstituted indolines.

Journal of the American Chemical Society published new progress about Bronsted acids Role: CAT (Catalyst Use), USES (Uses). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, 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

Konrad, Tina M.; Fuentes, Jose A.; Slawin, Alexandra M. Z.; Clarke, Matthew L. published the artcile< Highly Enantioselective Hydroxycarbonylation and Alkoxycarbonylation of Alkenes using Dipalladium Complexes as Precatalysts>, Application In Synthesis of 325168-88-5, the main research area is paracyclophane diphosphine palladium complex preparation enantioselective hydroxycarbonylation alkoxycarbonylation catalyst; styrene norbornene asym hydroxycarbonylation alkoxycarbonylation palladium phanephos catalyst.

A highly stereoselective process for hydroxycarbonylation and alkoxycarbonylation of alkenes [styrene, 4-(tert-butyl)styrene, norbornene] using (R)-PHANEPHOS- and (R)- or (S)-Xylyl-PHANEPHOS-bridged dipalladium complexes as precatalysts has been developed. The process operates below 100 °C, uses less than 1 equivalent of an acid promoter and delivers the product with up to 95% ee.

Angewandte Chemie, International Edition published new progress about Aliphatic acids Role: SPN (Synthetic Preparation), PREP (Preparation). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Application In Synthesis of 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; Takano, Ryo; Nozaki, Kyoko published the artcile< Rhodium-catalyzed asymmetric synthesis of silicon-stereogenic silicon-bridged arylpyridinones>, Category: chiral-phosphine-ligands, the main research area is rhodium catalyzed asym synthesis silicon stereogenic bridged arylpyridinone; cycloaddition silyl prochiral triyne isocyanate rhodium catalyzed; alkynyl benzopyridosilacyclopentene preparation crystal mol structure.

A rhodium-catalyzed regio- and enantioselective synthesis of silicon-stereogenic silicon-bridged arylpyridinones has been developed through [2 + 2 + 2] cycloaddition of silicon-containing prochiral triynes with isocyanates. High yields and enantioselectivities have been achieved by employing an axially chiral monophosphine ligand, and this process could be applied to catalytic asym. synthesis of silicon-stereogenic chiral polymers for the first time. The reaction mechanism of the present catalysis has also been exptl. investigated to establish a reasonable catalytic cycle, advancing the mechanistic understanding of the rhodium-catalyzed pyridinone synthesis by [2 + 2 + 2] cycloaddition reactions.

Chemical Science published new progress about [2+2+2] Cycloaddition reaction. 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Category: chiral-phosphine-ligands.

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

Valli, Matteo; Bruno, Paolo; Sbarbada, Davide; Porta, Alessio; Vidari, Giovanni; Zanoni, Giuseppe published the artcile< Stereodivergent Strategy for Neurofuran Synthesis via Palladium-Catalyzed Asymmetric Allylic Cyclization: Total Synthesis of 7-epi-ST-Δ8-10-Neurofuran>, Computed Properties of 152140-65-3, the main research area is neurofuran synthesis asym allylic cyclization.

An enantioselective stereodivergent approach to two key neurofuran precursors, belonging to the AC and ST classes, has been developed starting from a single achiral precursor. The absolute configuration of the THF cores was secured by a Pd-catalyzed asym. allylic alkylation. From the ST precursor, 7-epi-ST-Δ8-10-neurofuran (I) was prepared

Journal of Organic Chemistry published new progress about Allylic alkylation, stereoselective. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Computed Properties 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

Shibata, Takanori; Fujimoto, Masako; Hirashima, Hiroyuki; Chiba, Tatsuya; Endo, Kohei published the artcile< Facile synthesis of cyclic polyphenylenes by consecutive inter- and intramolecular cycloadditions of ortho-, meta-, and para-phenylene-tethered triynes>, Formula: C44H40P2, the main research area is cyclic polyphenylene synthesis phenylene tethered triyne.

Consecutive inter- and intramol. [2 + 2 + 2] cycloadditions of various phenylene-tethered triynes were comprehensively studied by using chiral rhodium catalysts. Ortho-Phenylene-tethered triynes gave chiral o,o,o,o-tetraphenylenes in high-to-excellent enantiomeric excess as dimers. Meta-Phenylene-tethered triynes gave chiral o,m,o,m-tetraphenylenes in moderate enantiomeric excess as dimers along with hexaphenylenes as trimers. This is the first synthesis of cis-o,m,o,m-tetraphenylenes; one structure was ascertained by X-ray crystal structure anal. Para-Phenylene-tethered triynes gave o,p,o,p,o,p-hexaphenylenes as trimers along with the formation of o,p,o,p,o,p,o,p-octaphenylenes as tetramers.

Synthesis published new progress about Alkynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, 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