Day: October 13, 2022

Jolin, Trinidad; Morreale de Escobar, Gabriella published the artcile< Deiodination of L-thyroxine and its activity on the oxidation in vitro of reduced nicotinamide adenine dinucleotide by peroxidase plus hydrogen peroxide>, 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 thyroxine deiodination NADH oxidation; peroxidase peroxide NADH thyroxine.

When L-thyroxine [51-48-9] activated the oxidation of disodium NADH [606-68-8] by horseradish peroxidase (EC 1.11.1.7) + hydrogen peroxide [7722-84-1], little removal of phenolic ring iodine [7553-56-2] atoms became apparent until most of the NADH had been oxidized, after which it increased markedly. This extensive deiodination was accompanied by loss of the ability of thyroxine to catalyze the oxidation of NADH by peroxidase + H2O2. ICN [506-78-5], but not I2 or thyronine [1596-67-4], catalyzed NADH oxidn in both the presence and absence of peroxidase + H2O2. Thyroxine + peroxidase + H2O2 were comparable with ICN alone in their effects on NADH oxidation The obvious results that the active moiety is the halogen liberated from thyroxine or ICN were not directly supported by some of the results obtained by measuring the degree of deiodination of thyroxine in the system. Possible explanations of these apparently contradictory conclusions were discussed.

Biochemical Journal published new progress about Deiodination. 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

Zhu, Guang-Yu; Zhai, Tong-Yi; Li, Xiao; Shi, Chong-Yang; Zhu, Xin-Qi; Ye, Long-Wu published the artcile< Copper-Catalyzed Cyclization of N-Propargyl Ynamides with Borane Adducts through B-H Bond Insertion>, Reference of 139139-86-9, the main research area is propargyl ynamide preparation copper catalyzed borylation cyclization borane adduct; amineboranyl arylpyrrole derivative preparation crystal structure borylation oxidation; mol structure amineboranyl arylpyrrole derivative; amine boranyl aryl pyrrole derivative preparation.

An efficient Cu-catalyzed cyclization of N-propargyl ynamides with borane adducts through B-H bond insertion was developed. Valuable organoboron compounds are constructed in generally good yields with a wide substrate scope and good functional group tolerance under mild reaction conditions. Importantly, this protocol via vinyl cation intermediates constitutes a novel way of B-H bond insertion.

Organic Letters published new progress about Boranes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation) ((amine-boranyl)(aryl)pyrrole derivatives). 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

Yoshida, Mariko; Nemoto, Tetsuhiro; Zhao, Zengduo; Ishige, Yuta; Hamada, Yasumasa published the artcile< Enantioselective construction of all-carbon quaternary spirocenters through a Pd-catalyzed asymmetric intramolecular ipso-Friedel-Crafts allylic alkylation of phenols>, Name: N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide], the main research area is spirocyclohexadienone enantioselective synthesis; phenol Friedel Crafts allylic alkylation chiral ligand Pd catalyst.

A novel catalytic asym. synthetic method for making spirocyclohexadienones e. g., I with an all-carbon quaternary spirocenter was developed based on the Pd-catalyzed intramol. ipso-Friedel-Crafts allylic alkylation of phenols. When 5 mol % of the Pd catalyst and 12 mol % of (-)-9-NapBN (-) were used, the spirocyclic adduct was obtained with up to 93% ee, albeit with low chem. yield. On the other hand, when using 6 mol% of the Trost ligand (R,R), the spirocyclic adducts were obtained in good yields with up to 89% ee (diastereoselectivity = 9.2:1).

Tetrahedron: Asymmetry published new progress about Allylic alkylation. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Name: N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide].

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

Wangler, Anton; Loll, Rouven; Greinert, Thorsten; Sadowski, Gabriele; Held, Christoph published the artcile< Predicting the high concentration co-solvent influence on the reaction equilibria of the ADH-catalyzed reduction of acetophenone>, Related Products of 606-68-8, the main research area is acetophenone alc dehydrogenase catalyst cosolvent effect reduction equilibrium.

The use of co-solvents for the enhancement of the reaction parameters reaction rate, yield and enantioselectivity is an established optimization strategy in biotechnol. To determine the influence of co-solvents on even one of these reaction parameters requires a great amount of exptl. data. Thus, predictive and phys. sound models are desired to decrease the amount of exptl. effort. This work aims at providing such a framework, which was applied to the ADH (alc. dehydrogenase)-catalyzed reduction of acetophenone at 303.15 K and 1 bar in water (neat) and under the influence of up to 20 wt-% of polyethylene glycol (PEG) and 15 wt-% trisodium citrate (Na3Cit). In a first step, the equilibrium composition was measured at constant pH. It was then shown that high concentration of PEG or Na3Cit changed the equilibrium position significantly (up to a factor of 13) compared to neat reaction mixtures To be able to predict this strong co-solvent influence on the reaction equilibrium, the exptl. determined equilibrium compositions of the neat reaction were converted into a thermodn. equilibrium constant Kth using the activity coefficients γi of the reacting agents. The latter were predicted by electrolyte perturbed-chain statistical associating fluid theory (ePC-SAFT). These finally allowed quant. predicting the high concentration co-solvent influence on the equilibrium position.

Journal of Chemical Thermodynamics published new progress about Cosolvents. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Related Products 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

Kaiser, Thomas M.; Yang, Jiong published the artcile< Catalytic Enantioconvergent Decarboxylative Allylic Alkylation of Allyl Indolenine-3-carboxylates>, SDS of cas: 152140-65-3, the main research area is indole allyl asym synthesis; indolenine carboxylate allyl preparation enantioconvergent decarboxylative allylic alkylation.

A catalytic enantioconvergent process has been developed for the conversion of racemic allyl indolenine-3-carboxylates I (R1 = H, Cl, Me, MeO; R2 = MeCOCH2CH2, MeCH:CHCH2, PhCH2, 2-naphthylmethyl, etc.; R3 = H2C:CH, MeCH:CH, H2C:CMe) into enantiomerically enriched C3-quaternary indolenines II. A Pd-catalyzed decarboxylative allylic alkylation reaction was employed for both stereoablation of the racemic allyl indolenine-3-carboxylates and enantioselective formation of the quaternary carbon center.

European Journal of Organic Chemistry published new progress about Allylic alkylation catalysts, stereoselective. 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

Alame, Mohamad; Pestre, Nathalie; de Bellefon, Claude published the artcile< Extensive re-investigations of pressure effects in rhodium-catalyzed asymmetric hydrogenations>, Electric Literature of 325168-88-5, the main research area is pressure effect rhodium catalysis asym hydrogenation.

The catalytic hydrogenation of three prochiral substrates Me Z-α-acetamidocinnamate (MAC), Me 2-acetamidoacrylate (M-Acrylate) and Et 4-methyl-3-acetamido-2-propanoate (E-EMAP) with rhodium precursors complexed with chiral diphosphines is reported at 1-30 bar hydrogen pressure. A library of 56 chiral diphosphines, including 23 BINAP derivatives, 7 JOSIPHOS, 5 BIPHEP, 3 DUPHOS derivatives, and 18 other ligands, was used. While it was generally accepted that high hydrogen pressure would result in lower ees, it is now demonstrated on a statistical basis that an equivalent distribution between beneficial and detrimental pressure effects on ee prevails and that the hydrogen pressure effect on enantioselectivity is not an isolated phenomenon since more than 33% of the reaction systems studied are strongly affected. In some case, the enantioselectivity can be improved up to 97% just by applying a higher hydrogen pressure. Extension of these conclusions to other non-chiral reagents is proposed.

Advanced Synthesis & Catalysis published new progress about Hydrogenation. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Electric Literature 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

Starkov, Pavel; Moore, Jared T.; Duquette, Douglas C.; Stoltz, Brian M.; Marek, Ilan published the artcile< Enantioselective Construction of Acyclic Quaternary Carbon Stereocenters: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully Substituted Amide Enolates>, Safety of N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide], the main research area is enantioselective preparation acyclic quaternary carbon stereocenter; palladium catalyzed decarboxylative allylic alkylation amide enolate.

Authors report a divergent and modular protocol for the preparation of acyclic mol. frameworks containing newly created quaternary carbon stereocenters. Central to this approach is a sequence composed of a (1) regioselective and -retentive preparation of allyloxycarbonyl-trapped fully substituted stereodefined amide enolates and of a (2) enantioselective palladium-catalyzed decarboxylative allylic alkylation reaction using a novel bisphosphine ligand.

Journal of the American Chemical Society published new progress about Allylic alkylation (enantioselective). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Safety of N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide].

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

Lautens, Mark; Fagnou, Keith; Yang, Dingqiao published the artcile< Rhodium-Catalyzed Asymmetric Ring Opening Reactions of Oxabicyclic Alkenes: Application of Halide Effects in the Development of a General Process>, Category: chiral-phosphine-ligands, the main research area is alkene oxabicyclic rhodium catalyzed asym ring opening nucleophile; naphthalenol dihydro asym synthesis; halide effect asym ring opening oxabicyclic alkene.

The halide effects in the rhodium-catalyzed asym. ring opening reaction of oxabicyclic alkenes, e.g. I, with various nucleophiles to give the corresponding dihydronaphthalenols, e.g. II [R = Et2N, 4-MeOC6H4NH, 4-methylpiperazin-1-yl, 3-indolyl, (MeO2C)2CH, 2-FC6H4O, etc.], are demonstrated. By employing halide and protic additives, the catalyst poisoning effect of aliphatic amines is reversed allowing the nucleophile to react in high yield and ee. Second, by simply changing the halide ligand on the rhodium catalyst from chloride to iodide, the reactivity and enantioselectivity of reactions employing an aromatic amine, malonate or carboxylate nucleophile are dramatically improved. Third, through the application of halide effects and more forcing reaction conditions, less reactive oxabicycle [2.2.1] substrates react to generate synthetically useful enantioenriched cyclohexenol products. Application of these new conditions to the more reactive oxabenzonorbornadiene I permits the reaction to be run with very low catalyst loadings (0.01 mol %).

Journal of the American Chemical Society published new progress about Alcohols, chiral Role: SPN (Synthetic Preparation), PREP (Preparation). 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, 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

Tsukamoto, Hirokazu; Suzuki, Risako; Kondo, Yoshinori published the artcile< Revisiting Benzenesulfonyl Linker for the Deoxygenation and Multifunctionalization of Phenols>, Computed Properties of 277306-29-3, the main research area is arene preparation solid phase; aryl amine thioether cycloheptanone preparation solid phase; biaryl preparation solid phase; reductive cleavage resin bound aryl sulfonate palladium catalyst; coupling reaction resin bound aryl sulfonate palladium nickel catalyst; benzenesulfonyl linker deoxygenation functionalization phenol derivative preparation; benzenesulfonic benzenesulfonyl linker deoxygenation functionalization phenol derivative preparation.

Arenes are prepared by sulfonylation of phenols with a resin-bound benzenesulfonyl chloride followed by palladium- and nickel-catalyzed reductive cleavage and coupling reactions to yield arenes, benzamides, aryl amines, biaryls, aryl thioethers, and an arylcycloheptanone. The effect of changes of ligand and palladium catalyst on the palladium-catalyzed reductive cleavage of 4-tosyloxyacetanilide to acetanilide is studied as a test case for the solid-phase reductive cleavage reactions.

Journal of Combinatorial Chemistry published new progress about Aromatic hydrocarbons Role: SPN (Synthetic Preparation), PREP (Preparation). 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, Computed Properties of 277306-29-3.

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

Ludvik, J.; Volke, J. published the artcile< Evidence for a radical intermediate in the anodic oxidation of reduced nicotinamide adenine dinucleotides obtained by electrogenerated chemiluminescence>, Category: chiral-phosphine-ligands, the main research area is electrooxidation product reduction nicotinamide adenine dinucleotide; adenine derivative electrochemiluminescence; chemiluminescence adenine derivative; radical intermediate redox reaction adenine derivative.

Electrogenerated chemiluminescence is used to show that the radicals NAD• and NADP• are intermediates in the electrooxidation of NADH and NADPH at a Pt anode in anhydrous or partly aqueous (up to 15 volume%) DMSO. An ECE mechanism seems to predominate. The use of DMSO proved to be very convenient, with the advantage of enabling electrogenerated chemiluminescence to be obtained in partly aqueous media even with ionic substances as substrates. The method is useful in proving the existence of unstable radical intermediates in redox processes, even for relatively large mols. such as NADH and NADPH.

Analytica Chimica Acta published new progress about Adsorption. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, 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