Day: October 14, 2022

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

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

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

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

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

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