Tag: M.W:300-400

Children learn through play, and they learn more than adults might expect. Science experiments are a great way to spark their curiosity, get their minds active, and encourage them to do something that doesn¡¯t involve a screen. 1038-95-5, C21H21P. A document type is Article, introducing its new discovery., Application In Synthesis of Tri-p-tolylphosphine

Structural properties and dissociative fluxional motion of 2,9-dimethyl-1,10-phenanthroline in platinum(II) complexes

A dynamic 1H NMR study has been carried out on the fluxional motion of the symmetric chelating ligand 2,9-dimethyl-1,10-phenanthroline (Me2-phen) between nonequivalent exchanging sites in a variety of square-planar complexes of the type [Pt(Me)(Me2-phen)(PR 3)]BArf, 1-14, (BArf = 8[3,5-(CF3)2C 6H3]4. In these compounds, the P-donor ligands PR3 encompass a wide range of steric and electronic characteristics [PR3 = P(4-XC6H4)3, X = H 1, F, 2, Cl 3, CF3 4, MeO 5, Me 6; PR3 = PMe2(C 6H5)2 7, PMe2(C6H 5) 8, PMe3 9, PEt3 10, P(i-Pr)3 11, PCy(C6H5)2 12, PCy2(C 6H5) 13, PCy3 14]. All complexes have been synthesized and fully characterized through elemental analysis, 1H and 31P{1H} NMR. X-ray crystal structures are reported for the compounds 8, 11, 14, and for [Pt-(Me)(phen)(P(C6H 5)3)]PF6 (15), all but the last showing loss of planarity and a significant rotation of the Me2-phen moiety around the N1-N2 vector. Steric congestion brought about by the P-donor ligands is responsible for tetrahedral distortion of the coordination plane and significant lengthening of the Pt-N2 (cis to phosphane) bond distances. Application of standard quantitative analysis of ligand effects (QALE) methodology enabled a quantitative separation of steric and electronic contributions of P-donor ligands to the values of the platinum-phosphorus 1JPtP coupling constants and of the free activation energies DeltaG? of the fluxional motion of Me2-phen in 1-14. The steric profiles for both 1JPtP and DeltaG? show the onset of steric thresholds (at cone angle values of 150 and 148, respectively), that are associated with an overload of steric congestion already evidenced by the crystal structures of 11 and 14. The sharp increase of the fluxional rate of Me2-phen can be assumed as a perceptive kinetic tool for revealing ground-state destabilization produced by the P-donor ligands. The mechanism involves initial breaking of a metal-nitrogen bond, fast interconversion between two 14-electron three-coordinate T-shaped intermediates containing eta1-coordinated Me2-phen, and final ring closure. By use of the results from QALE regression analysis, a free-energy surface has been constructed that represents the way in which any single P-donor ligand can affect the energy of the transition state in the absence of aryl or pi-acidity effects.

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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

Related Products of 17261-28-8. Chemistry is an experimental science, and the best way to enjoy it and learn about it is performing experiments.Introducing a new discovery about 17261-28-8, Name is 2-(Diphenylphosphino)benzoic acid

Asymmetric synthesis of (-)-anatoxin-a via an asymmetric cyclization using a new ligand for Pd-catalyzed alkylations

Palladium-catalyzed asymmetric allylic alkylations have been explored in the context of medium-sized ring substrates, intramolecular vs intermolecular processes involving attack on a formally meso pi-allyl intermediate in the desymmetrization, and the presence of electron-withdrawing groups on the cationic pi-allylpalladium intermediate. The synthesis of anatoxin-a, also known as the ‘very fast death factor’, raises all of these questions. Ligands derived from trans-1,2-diaminocyclohexane and 2-diphenylphosphinobenzoic acid effect asymmetric alkylations with an allyl substrate bearing an electron- withdrawing group. On the other hand, a new type of ligand wherein the diamine is derivatized with both 2-diphenylphosphinobenzoic acid and 2- picolinic acid was required to effect asymmetric cyclization to form the 9- azabicyclo[4.2.1]non-2-ene system. A total synthesis of anatoxin-a from 5- hydroxy-1,8-nonadiene employing a metathesis reaction to form the cycloheptene and a palladium-catalyzed asymmetric cyclization to form the bicyclic ring system is achieved in 15% overall yield.

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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

Electric Literature of 240417-00-9, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 240417-00-9, Name is 2-Diphenylphosphino-2′-(N,N-dimethylamino)biphenyl, molecular formula is C26H24NP. In a Article£¬once mentioned of 240417-00-9

Enzyme level N and O isotope effects of assimilatory and dissimilatory nitrate reduction

To provide mechanistic constraints to interpret nitrogen (N) and oxygen (O) isotope ratios of nitrate ((Formula presented.)), 15N/14N and 18O/16O, in the environment, we measured the enzymatic (Formula presented.) N and O isotope effects (15epsilon and 18epsilon) during its reduction by (Formula presented.) reductase enzymes, including (1) a prokaryotic respiratory (Formula presented.) reductase, Nar, from the heterotrophic denitrifier Paracoccus denitrificans, (2) eukaryotic assimilatory (Formula presented.) reductases, eukNR, from Pichia angusta and from Arabidopsis thaliana, and (3) a prokaryotic periplasmic (Formula presented.) reductase, Nap, from the photoheterotroph Rhodobacter sphaeroides. Enzymatic Nar and eukNR assays with artificial viologen electron donors yielded identical 18epsilon and 15epsilon of ?28?, regardless of [(Formula presented.)] or assay temperature, suggesting analogous kinetic mechanisms with viologen reductants. Nar assays fuelled with the physiological reductant hydroquinone (HQ) also yielded 18epsilon???15epsilon, but variable amplitudes from 21? to 33.0? in association with [(Formula presented.)], suggesting analogous substrate sensitivity in vivo. Nap assays fuelled by viologen revealed 18epsilon:15epsilon of 0.50, where 18epsilon???19? and 15epsilon???38?, indicating a distinct catalytic mechanism than Nar and eukNR. Nap isotope effects measured in vivo showed a similar 18epsilon:15epsilon of 0.57, but reduced 18epsilon???11? and 15epsilon???19?. Together, the results confirm identical enzymatic 18epsilon and 15epsilon during (Formula presented.) assimilation and denitrification, reinforcing the reliability of this benchmark to identify (Formula presented.) consumption in the environment. However, the amplitude of enzymatic isotope effects is apt to vary in vivo. The distinctive signature of Nap is of interest for deciphering catalytic mechanisms but may be negligible in most environments given its physiological role.

The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 240417-00-9 is helpful to your research., Electric Literature of 240417-00-9

Reference£º
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

Electric Literature of 1038-95-5, An article , which mentions 1038-95-5, molecular formula is C21H21P. The compound – Tri-p-tolylphosphine played an important role in people’s production and life.

Iridium(III)-Catalyzed C?H Amidation of Arylphosphoryls Leading to a P-Stereogenic Center

Direct C?H amidation of arylphosphoryl compounds has been developed by using an IrIIIcatalyst system under mild conditions. A wide range of substrates could be employed with high functional-group tolerance. This procedure was successfully applied for the first time to the asymmetric reaction giving rise to a P-chirogenic center with a high diastereomeric ratio of up to 19:1 (90 % de).

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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

A catalyst don’t appear in the overall stoichiometry of the reaction it catalyzes, but it must appear in at least one of the elementary reactions in the mechanism for the catalyzed reaction. 1038-95-5, Name is Tri-p-tolylphosphine, molecular formula is C21H21P. In a Article£¬once mentioned of 1038-95-5, Quality Control of: Tri-p-tolylphosphine

Multicomponent reactions of phosphines, enynedioates and benzylidene malononitriles generated highly substituted cyclopentenes through an unexpected phosphine alpha-addition-delta-evolvement of an anion pathway

Multicomponent reactions of phosphines, enynedioates and benzylidene malononitriles provide highly substituted syn-selective cyclopentenes appending the phosphorus ylide moiety in good yield with a diastereoselectivity of up to 100% through resonance-derived 1,5-dipolar species as the key intermediates, via the nucleophilic alpha(delta?)-attack of phosphines toward enynedioates followed by addition to benzylidene malononitriles and 5-exo-dig cyclization. Through computational analyses, the overall reactions for the formation of syn- and anti-diastereomers are both exothermic with 65.6 and 66.3 kcal mol-1 at the B3LYP-D3/6-31G(d) level of theory and were found to be kinetically controlled, which favours the formation of syn-diastereomers.

Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Quality Control of: Tri-p-tolylphosphine. In my other articles, you can also check out more blogs about 1038-95-5

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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

Related Products of 155613-52-8, Catalysts are substances that increase the reaction rate of a chemical reaction without being consumed in the process. 155613-52-8, Name is (R)-1,1-Binaphthyl-2,2-diyl phosphorochloridate, molecular formula is C20H12ClO2P. In a Patent£¬once mentioned of 155613-52-8

chiral Asian phosphine amide monodentate ligand and its synthetic method and application (by machine translation)

The invention relates to chiral Asian phosphine amide monodentate ligand and its synthetic method and application, the chiral Asian phosphine amide monodentate ligand with a monovalent metal iridium or rhodium prepared by complexation of the catalyst, the catalyst is used for the beta-aryl amine compound synthetic reaction, beta-aryl amine compound is a pharmacophore many important drugs. The present invention provides such ligand, can make the obtaining of beta-aryl amine compound catalyst for asymmetric reductive amination of 5/100000 consumption is reduced to, at the same time of the product beta-arylamines enantioselecivity can reach 98% ; at the same time air-stable catalyst used, the reaction can be operated in aerobic environment, thereby greatly simplifying the manufacturing operation. (by machine translation)

The proportionality constant is the rate constant for the particular unimolecular reaction. the reaction rate is directly proportional to the concentration of the reactant. I hope my blog about 155613-52-8 is helpful to your research., Related Products of 155613-52-8

Reference£º
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

Application of 1038-95-5, An article , which mentions 1038-95-5, molecular formula is C21H21P. The compound – Tri-p-tolylphosphine played an important role in people’s production and life.

Photochemistry of the luminescent alkyl complexes alkyl(carbonyl)bis(triarylphosphine)(maleonitrile-dithiolato)iridium, IrR(CO)(PAr3)2(mnt)

A series of luminescent alkyl complexes of formula IrR(CO)L2(mnt), where mnt = maleonitriledithiolate, R = Me, Et, Pr, and CH2CN, and L is a triarylphosphine, have been synthesized and characterized. The complexes posses octahedral coordination geometries with the phosphine ligands in mutually trans positions, as confirmed by a crystal structure determination of the methyl derivative. Crystal data for IrMe(CO)(PPh3)2(mnt): IrS2P2ON2C42H33, triclinic space group P1, a = 13.178(4) A, b = 13.670(4) A, c = 12.592(2) A, a = 105.03(2), beta = 115.42(2), gamma = 95.72(2), V = 1919.9 A3; Z = 2, 6298 reflections (h, ¡Àk, ¡Àl, 4 < 26 < 45), R1 = 0.020, R2 = 0.028, and GOF = 1.09. The Ir-S distances of 2.442(1) and 2.371(1) A reflect the structural influence of the trans ligands (Me and CO, respectively). The alkyl complexes luminesce in fluid solution with an emission energy in the range of 695-780 nm and a band shape that suggests vibronic structure characteristic of other mnt complexes. Photolysis of IrMe-(CO) (PPh3)2(mnt) in the presence of H-atom sources and radical traps leads to products consistent with Ir-alkyl bond homolysis. Further photochemical studies in the presence of 13CO suggest that Ir-Me bond homolysis is favored strongly over CO photodissociation. Photochemistry of IrR(CO)(PPh3)2(mnt), where R contains beta-hydrogens, produces only the beta-elimination products of olefin and the hydride complex IrH(CO)(PPh3)2(mnt) even in the presence of large excesses of phosphine, CO, or different radical trapping agents. The quantum yield for photochemical beta-elimination of 0.30 is much greater than that determined for photochemical disappearance of IrMe(CO)L2(mnt) and is consistent with an efficient H-atom transfer from R to Ir(CO)L2(mnt) within the radical pair generated by photolysis. I hope this article can help some friends in scientific research. I am very proud of our efforts over the past few months and hope to 1038-95-5, help many people in the next few years., Application of 1038-95-5

Reference£º
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

A catalyst don’t appear in the overall stoichiometry of the reaction it catalyzes, but it must appear in at least one of the elementary reactions in the mechanism for the catalyzed reaction. 29949-84-6, Name is Tris(3-methoxyphenyl)phosphine, molecular formula is C21H21O3P. In a Article£¬once mentioned of 29949-84-6, name: Tris(3-methoxyphenyl)phosphine

Syntheses of RuHCl(CO)(PAr3)3 and RuH2(CO)(PAr3)3 Containing various triarylphosphines and their use for arylation of sterically congested aromatic C-H bonds

A series of ruthenium complexes, RuHCl(CO)(PAr3)3 and RuH2(CO)(PAr3)3, containing various triarylphosphines were synthesized. Screening of these complexes as catalysts for direct arylation of sterically congested ortho C-H bonds of aromatic ketones improved the yields of the arylation products.

Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data.name: Tris(3-methoxyphenyl)phosphine, If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 29949-84-6, in my other articles.

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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

In an article, published in an article, once mentioned the application of 131211-27-3, Name is Di(adamantan-1-yl)phosphine,molecular formula is C20H31P, is a conventional compound. this article was the specific content is as follows.Formula: C20H31P

DI-1-ADAMANTYLPHOSPHIN, EIN SRERISCH HOCH GEHINDERTES SEKUNDAERES PHOSPHIN. DARSTELLUNG UND REAKTIONEN

Di-1-adamantylphosphine 1 was synthesized by reduction of (1-Ad)2P(:O)Cl with LiAlH4 or HSiCl3.The reaction of 1 with H2O2, elemental sulfur and selenium afforded the corresponding secondary phosphine oxides, sulfides and selenides, (1-Ad)2P(:X)H (X = O, S, Se).In the reaction of 1 with two equivalents of Me3SiN3 oxidation occured with formation of (1-Ad)2P(:NSiMe3)NHSiMe3 6.Despite the steric hindrance, MeI quaternized the P-atom in 1 to give <(1-Ad)2PHMe>I 7.The phosphine (1-Ad)2PMe 8 was formed in the reaction of 7 with NEt3 and was oxidized by O2 to give (1-Ad)2P(:O)-Me 9.Key words: Di-1-adamantylphosphine; Di-1-adamantylphosphine oxide, sulfide, selenide, NMR.

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Reference£º
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

224311-49-3, Name is 2′-(Di-tert-butylphosphino)-N,N-dimethyl-[1,1′-biphenyl]-2-amine, molecular formula is C22H32NP, belongs to chiral-phosphine-ligands compound, is a common compound. In a patnet, once mentioned the new application about 224311-49-3, Computed Properties of C22H32NP

Novel electron-rich bulky phosphine ligands facilitate the palladium-catalyzed preparation of diaryl ethers

A general method for the palladium-catalyzed formation of diaryl ethers is described. Electron-rich, bulky aryldialkylphosphine ligands, in which the two alkyl groups are either tert-butyl or 1-adamantyl, are the key to the success of the transformation. A wide range of electron-deficient, electronically neutral and electron-rich aryl bromides, chlorides, and triflates can be combined with a variety of phenols with the use of sodium hydride or potassium phosphate as base in toluene at 100 C. The bulky yet basic nature of the phosphine ligand is thought to be responsible for increasing the rate of reductive elimination of the diaryl ether from palladium.

Balanced chemical reaction does not necessarily reveal either the individual elementary reactions by which a reaction occurs or its rate law.Computed Properties of C22H32NP. In my other articles, you can also check out more blogs about 224311-49-3

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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