October 2022 | Page 34 of 44 | Chiral phosphine ligands

Trost, Barry M’s team published research in Journal of the American Chemical Society in 2009-09-02 | 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, Category: chiral-phosphine-ligands.

Trost, Barry M.; Thaisrivongs, David A. published the artcile< Palladium-Catalyzed Regio-, Diastereo-, and Benzylic Allylation of 2-Substituted Pyridines>, Category: chiral-phosphine-ligands, the main research area is regioselective diastereoselective enantioselective palladium catalyst allylic alkylation pyridine.

We report a new method for the highly regio-, diastereo-, and enantioselective palladium-catalyzed allylic alkylation of 2-substituted pyridines that allows for the formation of homoallylic stereocenters containing alkyl, aryl, heteroaryl, and nitrogen substituents. When the reaction is conducted with asym. acyclic electrophiles, both linear and branched products may be obtained exclusively by selecting the appropriate regioisomeric starting material and ligand, an example of the “”memory effect.””. Deuterium-labeling studies reveal that though no such phenomenon occurs with racemic cyclic electrophiles, the chiral ligand employed reacts kinetically faster with the enantiomer of the substrate for which it is “”matched”” and yet eventually converts all “”mismatched”” substrate to product.

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

Kikuchi, Satoshi’s team published research in Chemistry Letters in 2010-06-05 | 139139-86-9

Chemistry Letters published new progress about Microwave irradiation. 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Name: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

Kikuchi, Satoshi; Tsubo, Tatsuyuki; Ashizawa, Tomoko; Yamada, Tohru published the artcile< Extraordinary effect of microwave irradiation on asymmetric catalysis>, Name: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is atropo enantioselective ring opening reaction biaryl lactone.

We here report the effect of microwave irradiation on the atropo-enantioselective ring-opening reaction of biaryl lactones with dynamic-kinetic resolution catalyzed by AgBF4-phosphine complexes. The multimode microwave reactor with a cooling system was employed and the fiber-optic sensor was used for measurement of the accurate internal reaction temperature The reaction was accelerated by microwave irradiation without any loss of enantioselectivity at almost the same internal temperature as the conventional conditions.

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.

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

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.