October 12, 2022 | Page 4 of 8 | Chiral phosphine ligands

Akula, Ramulu’s team published research in Chemistry – A European Journal in 2016 | 152140-65-3

Chemistry – A European Journal published new progress about Allyl group. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Category: chiral-phosphine-ligands.

Akula, Ramulu; Doran, Robert; Guiry, Patrick J. published the artcile< Highly enantioselective formation of α-allyl-α-arylcyclopentanones via Pd-catalysed decarboxylative asymmetric allylic alkylation>, Category: chiral-phosphine-ligands, the main research area is allyl alpha arylcyclopentanone enantioselective preparation; alpha aryl beta ketoester asym allylic alkylation ANDEN Trost; allylic alkylation; asymmetric catalysis; decarboxylation; natural products; palladium.

A highly enantioselective Pd-catalyzed decarboxylative asym. allylic alkylation of cyclopentanone derived α-aryl-β-keto esters employing the (R,R)-ANDEN-Ph Trost ligand was developed. The product (S)-α-allyl-α-arylcyclopentanones, e.g., I [Ar = 2,4,6-(MeO)3C6H2, 2,6-(MeO)2C6H3, 2,4-(MeO)2C6H3, etc.] were obtained in excellent yields and enantioselectivities (up to >99.9 % ee). This represented one of the most highly enantioselective formations of an all-carbon quaternary stereogenic center reported to date. This reaction was demonstrated on a 4.0 mmol scale without any deterioration of enantioselectivity and was exploited as the key enantioselective transformation in an asym. formal synthesis of the natural product (+)-tanikolide.

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

Ghosh, Santanu’s team published research in Chemistry – A European Journal in 2015 | 152140-65-3

Chemistry – A European Journal published new progress about Allylation catalysts, stereoselective. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Recommanded Product: N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide].

Ghosh, Santanu; Chaudhuri, Saikat; Bisai, Alakesh published the artcile< Catalytic Enantioselective Decarboxylative Allylations of a Mixture of Allyl Carbonates and Allyl Esters: Total Synthesis of (-)- and (+)-Folicanthine>, Recommanded Product: N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide], the main research area is enantioselective decarboxylative allylation allyl carbonate allyl ester palladium catalyst; folicanthine total synthesis; chimonanthine calycanthine ditryptophenaline formal synthesis; alkaloids; allylation; enantioselectivity; palladium; quaternary stereocentres.

A highly enantioselective decarboxylative allylation of a mixture of enol carbonates and allyl esters has been achieved. The strategic viability of this methodol. has been demonstrated through the total synthesis of cyclotryptamine alkaloids (-)- and (+)-folicanthine and the formal total synthesis of (-)-chimonanthine, (+)-calycanthine, and (-)-ditryptophenaline.

Trost, Barry M’s team published research in Journal of the American Chemical Society in 2005-12-14 | 152140-65-3

Journal of the American Chemical Society published new progress about Absolute configuration (product). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, HPLC of Formula: 152140-65-3.

Trost, Barry M.; Xu, Jiayi published the artcile< Palladium-Catalyzed Asymmetric Allylic α-Alkylation of Acyclic Ketones>, HPLC of Formula: 152140-65-3, the main research area is palladium catalyzed asym allylic alkylation acyclic ketone.

The first example of Pd-catalyzed asym. allyl alkylation of the conformationally nonrigid acyclic ketone enolates is reported with excellent yields, regioselectivity, and enantioselectivity. The double bond geometry of the allyl enol carbonates affects its reactivity, selectivity, as well as the absolute configuration of the products. An opposite enantioselectivity from what is predicted by a direct attack of the enolate on the allyl moiety of the π-ally-Pd complex was observed An alternative mechanism was proposed, which involves an inner sphere process of coordination of the enolate to Pd followed by reductive elimination.

Alexy, Eric J’s team published research in Organic Letters in 2017-10-06 | 152140-65-3

Organic Letters published new progress about Allylic alkylation (enantioselective, decarboxylative). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Application In Synthesis of 152140-65-3.

Alexy, Eric J.; Virgil, Scott C.; Bartberger, Michael D.; Stoltz, Brian M. published the artcile< Enantioselective Pd-Catalyzed Decarboxylative Allylic Alkylation of Thiopyranones. Access to Acyclic, Stereogenic α-Quaternary Ketones>, Application In Synthesis of 152140-65-3, the main research area is thiopyranone enantioselective decarboxylative allylic alkylation palladium reduction; acyclic stereogenic quaternary ketone enantioselective preparation; palladium enantioselective decarboxylative allylic alkylation catalyst.

A catalytic, enantioselective decarboxylative allylic alkylation of 4-thiopyranones is reported. The α-quaternary 4-thiopyranones produced are challenging to access by standard enolate alkylation owing to facile ring-opening β-sulfur elimination. In addition, reduction of the carbon-sulfur bonds provides access to elusive acyclic α-quaternary ketones. The alkylated products, e.g. I, were obtained in up to 92% yield and 94% enantiomeric excess.

Trost, Barry M’s team published research in Journal of the American Chemical Society in 2005-03-09 | 152140-65-3

Journal of the American Chemical Society published new progress about Allylic alkylation catalysts, stereoselective. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Electric Literature of 152140-65-3.

Trost, Barry M.; Xu, Jiayi published the artcile< Regio- and Enantioselective Pd-Catalyzed Allylic Alkylation of Ketones through Allyl Enol Carbonates>, Electric Literature of 152140-65-3, the main research area is enol allyl carbonate asym allylic alkylation palladium chiral ligand; palladium asym allylic alkylation catalyst; cyclic allylated ketone stereoselective preparation.

The Pd-catalyzed reorganization of enol allyl carbonates to allylated ketones occurs in the presence of chiral ligands that had been previously developed. With 2-methylcyclohexanone, asym. regioselective alkylation occurs at the more substituted carbon without complications of polyalkylation. Alkylation to create quaternary centers in indanones and benzosuberone occurs in much higher ee than using tin or lithium enolates. The sense of enantioinduction in tetralones is opposite from the tin and lithium enolate examples. For the first time, asym. preparation of tertiary centers occurs with high ee (78-99%). The different results between this reaction and the use of lithium or tin enolates suggest that different mechanisms may be involved.

Renom-Carrasco, Marc’s team published research in Chemistry – A European Journal in 2016 | 277306-29-3

Chemistry – A European Journal published new progress about Bases Role: RGT (Reagent), RACT (Reactant or Reagent). 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, Category: chiral-phosphine-ligands.

Renom-Carrasco, Marc; Gajewski, Piotr; Pignataro, Luca; de Vries, Johannes G.; Piarulli, Umberto; Gennari, Cesare; Lefort, Laurent published the artcile< Asymmetric Hydrogenation of 3-Substituted Pyridinium Salts>, Category: chiral-phosphine-ligands, the main research area is pyridinium salt asym hydrogenation; asymmetric catalysis; homogeneous catalysis; hydrogenation; pyridines; reaction mechanisms.

The use of an equivalent amount of an organic base leads to high enantiomeric excess in the asym. hydrogenation of N-benzylated 3-substituted pyridinium salts into the corresponding piperidines. Indeed, in the presence of Et3N, a Rh-JosiPhos catalyst reduced a range of pyridinium salts with ee values up to 90%. The role of the base was elucidated with a mechanistic study involving the isolation of the various reaction intermediates and isotopic labeling experiments Addnl., this study provided some evidence for an enantiodetermining step involving a dihydropyridine intermediate.

Ashizawa, Tomoko’s team published research in Chemistry Letters in 2009-03-05 | 139139-93-8

Chemistry Letters published new progress about Aromatic esters Role: SPN (Synthetic Preparation), PREP (Preparation) (biaryl). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Category: chiral-phosphine-ligands.

Ashizawa, Tomoko; Yamada, Tohru published the artcile< Catalytic atropo-enantioselective preparation of axially chiral biaryl compounds>, Category: chiral-phosphine-ligands, the main research area is biaryl lactone methanol chiral silver catalyst triisobutylamine ring opening; ester biaryl hydroxy derivative atropo stereoselective preparation; silver tetrafluoroborate binap derivative dynamic kinetic resolution catalyst.

The atropo-enantioselective ring-opening of biaryl lactones with methanol was catalyzed by an optically active AgBF4-phosphine complex to afford axially chiral biaryl compounds The addition of triisobutylamine provided a rate acceleration and increase in enantioselectivity in the reaction. Various types of axially chiral biaryl compounds were obtained with high enantioselectivity.

Alexy, Eric J’s team published research in Journal of the American Chemical Society in 2018-08-15 | 152140-65-3

Journal of the American Chemical Society published new progress about Allylic alkylation. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, HPLC of Formula: 152140-65-3.

Alexy, Eric J.; Zhang, Haiming; Stoltz, Brian M. published the artcile< Catalytic Enantioselective Synthesis of Acyclic Quaternary Centers: Palladium-Catalyzed Decarboxylative Allylic Alkylation of Fully Substituted Acyclic Enol Carbonates>, HPLC of Formula: 152140-65-3, the main research area is enol carbonate acyclic palladium phosphinooxazoline decarboxylative allylic alkylation catalyst; ketone quaternary stereoselective preparation.

The first enantioselective palladium-catalyzed decarboxylative allylic alkylation of fully substituted acyclic enol carbonates providing linear α-quaternary ketones is reported. Investigation into the reaction revealed that the use of an electron-deficient phosphinooxazoline ligand renders the enolate geometry of the starting material inconsequential, with the same enantiomer of product obtained in the same level of selectivity regardless of the starting ratio of enolates. As a result, a general method toward acyclic all-carbon quaternary stereocenters has been developed.

Augustine, Robert’s team published research in Chemical Industries (Boca Raton, FL, United States) in 2007 | 325168-88-5

Chemical Industries (Boca Raton, FL, United States) published new progress about Chiral ligands Role: CAT (Catalyst Use), USES (Uses). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Application of C48H50P2.

Augustine, Robert; Tanielyan, Setrak; Marin, Norman; Alvez, Gabriela published the artcile< Synthesis of chiral 2-amino-1-phenylethanol>, Application of C48H50P2, the main research area is aminophenylethanol stereoselective preparation phenacyl chloride.

Two methods for the synthesis of chiral 2-amino-1-phenylethanol have been developed. The first uses a chiral oxaborolidine catalyzed borane reduction of phenacyl chloride to give the chiral chloro alc. in very good yield with an ee in the 93%-97% range. Reaction with dilute ammonium hydroxide produced the amino alc. in very good yield with a high ee. The second approach involved the conversion of phenacyl chloride to the succinimide which was then hydrogenated using a chiral ruthenium complex in conjunction with a base and an optically active amine (Noyori procedure) to give the optically active succinimido alc. in very good yield with an ee of 98%. Hydrolysis with dilute base produced the optically active amino alc. in very good yield and excellent enantioselectivity.

Pandey, Krishna K’s team published research in Inorganic Chemistry in 2009-04-06 | 606-68-8

Inorganic Chemistry published new progress about Bond. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Name: ((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.

Pandey, Krishna K.; Lledos, Agusti published the artcile< Linear ME-Me Versus Bent M-E-Me: Bonding Analysis in Heavier Metal-ylidyne Complexes [(Cp)(CO)2MEMe] and Metallo-ylidenes [(Cp)(CO)3M-EMe] (M = Cr, Mo, W; E = Si, Ge, Sn, Pb)>, Name: ((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 bonding analysis transition metal ylidyne complex.

The electronic and mol. structures of the complexes [(η5-C5H5)(CO)2MEMe] and [(η5-C5H5)(CO)3M-EMe] (M = Cr, Mo, W; E = Si, Sn, Pb) are calculated at the d.-functional theory (DFT) level using the exchange correlation functionals B3LYP and BP86. The theor. predicted bond lengths and angles of the model compounds are in excellent agreement with exptl. values. The calculations reveal the presence of a strong ME triple (σ + 2π) bond in [(η5-C5H5)(CO)2MEMe]. The M-E bond lengths in [(η5-C5H5)(CO)3M-EMe] are longer than those expected for a single bond. The nature of the MEMe and M-EMe interactions was analyzed with charge and energy decomposition methods. In the MEMe bond, the M-E σ-bonding orbitals are always polarized toward the silicon, tin, and lead atoms, and the polarization increases from chromium to tungsten. In contrast, in the M-EMe bond, the M-E σ-bonding orbitals are significantly polarized toward the metal atom. The hybridization at the metal atoms in the ME bonds has d character in the range 60.6-68.8%, while in the M-E bonds has large d character which is always >86% of the total AO contribution. In the complexes [(η5-C5H5)(CO)2MEMe], the contributions of the electrostatic interactions, ΔEelstat, and the covalent bonding, ΔEorb, have nearly the same values for silylidyne and germylidyne complexes, while for the stannylidyne and plumbylidyne complexes, the electrostatic interactions, ΔEelstat, are greater than the orbital interaction, ΔEorb. The covalent bonding has a high degree of π-character. The total interaction energy ΔEint in the compound [(η5-C5H5)(CO)3M-EMe] is less attractive than those in the complexes [(η5-C5H5)(CO)2MEMe]. The M-ER bonds have a slightly lower degree of covalent bonding (34.9-44.9%) than the MEMe bonds (42.1-50.2%). The drastic difference between the two classes of compounds are found for the degree of a” (π) bonding. The contribution of ΔEπ to the covalent term ΔEorb is much higher in the MEMe bonding (41.6-42.6%) than in the M-EMe bonding (17.1-20.4%). While the π bonding contribution in [(η5-C5H5)(CO)3M-EMe] are weaker than those in [(η5-C5H5)(CO)2MEMe], the σ-bonding contribution in the former compounds are stronger than those in the latter.