Chiral phosphine ligands

Duan, Ying; Li, Lu; Chen, Mu-Wang; Yu, Chang-Bin; Fan, Hong-Jun; Zhou, Yong-Gui published the artcile< Homogeneous Pd-Catalyzed Asymmetric Hydrogenation of Unprotected Indoles: Scope and Mechanistic Studies>, Electric Literature of 139139-86-9, the main research area is homogeneous palladium catalyzed asym hydrogenation unprotected indole.

An efficient palladium-catalyzed asym. hydrogenation of a variety of unprotected indoles has been developed that gives up to 98% ee using a strong Bronsted acid as the activator. This methodol. was applied in the facile synthesis of biol. active products containing a chiral indoline skeleton. The mechanism of Pd-catalyzed asym. hydrogenation was investigated as well. Isotope-labeling reactions and ESI-HRMS proved that an iminium salt formed by protonation of the C=C bond of indoles was the significant intermediate in this reaction. The important proposed active catalytic Pd-H species was observed with 1H NMR spectroscopy. It was found that proton exchange between the Pd-H active species and solvent trifluoroethanol (TFE) did not occur, although this proton exchange had been previously observed between metal hydrides and alc. solvents. D. functional theory calculations were also carried out to give further insight into the mechanism of Pd-catalyzed asym. hydrogenation of indoles. This combination of exptl. and theor. studies suggests that Pd-catalyzed hydrogenation goes through a stepwise outer-sphere and ionic hydrogenation mechanism. The activation of hydrogen gas is a heterolytic process assisted by trifluoroacetate of Pd complex via a six-membered-ring transition state. The reaction proceeds well in polar solvent TFE owing to its ability to stabilize the ionic intermediates in the Pd-H generation step. The strong Bronsted acid activator can remarkably decrease the energy barrier for both Pd-H generation and hydrogenation. The high enantioselectivity arises from a hydrogen-bonding interaction between N-H of the iminium salt and oxygen of the coordinated trifluoroacetate in the eight-membered-ring transition state for hydride transfer, while the active chiral Pd complex is a typical bifunctional catalyst, effecting both the hydrogenation and hydrogen-bonding interaction between the iminium salt and the coordinated trifluoroacetate of Pd complex. Notably, the Pd-catalyzed asym. hydrogenation is relatively tolerant to oxygen, acid, and water.

Journal of the American Chemical Society published new progress about Acid catalysis (strong Bronsted acids as activators). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Electric Literature 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

Chen, Yijing; Li, Peng; Noh, Hyunho; Kung, Chung-Wei; Buru, Cassandra T.; Wang, Xingjie; Zhang, Xuan; Farha, Omar K. published the artcile< Stabilization of Formate Dehydrogenase in a Metal-Organic Framework for Bioelectrocatalytic Reduction of CO2>, Application of C21H27N7Na2O14P2, the main research area is formate dehydrogenase metal organic framework bioelectrocatalytic reduction carbon dioxide; bioelectrocatalysis; carbon dioxide fixation; formate dehydrogenase stabilization; mesoporous material.

The efficient fixation of excess CO2 from the atm. to yield value-added chems. remains crucial in response to the increasing levels of carbon emission. Coupling enzymic reactions with electrochem. regeneration of cofactors is a promising technique for fixing CO2, while producing biomass which can be further transformed into biofuels. Herein, a bioelectrocatalytic system was established by depositing crystallites of a mesoporous metal-organic framework (MOF), termed NU-1006, containing formate dehydrogenase, on a fluorine-doped tin oxide glass electrode modified with Cp*Rh(2,2′-bipyridyl-5,5′-dicarboxylic acid)Cl2 complex. This system converts CO2 into formic acid at a rate of 79±3.4 mM h-1 with electrochem. regeneration of the NAD cofactor. The MOF-enzyme composite exhibited significantly higher catalyst stability when subjected to non-native conditions compared to the free enzyme, doubling the formic acid yield.

Angewandte Chemie, International Edition published new progress about Biocatalysis. 606-68-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C21H27N7Na2O14P2, Application of C21H27N7Na2O14P2.

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

Kim, In Su; Ngai, Ming-Yu; Krische, Michael J. published the artcile< Enantioselective Iridium-Catalyzed Carbonyl Allylation from the Alcohol or Aldehyde Oxidation Level via Transfer Hydrogenative Coupling of Allyl Acetate: Departure from Chirally Modified Allyl Metal Reagents in Carbonyl Addition>, Application In Synthesis of 139139-86-9, the main research area is alc enantioselective iridium catalyzed carbonyl allylation; oxidation level transfer hydrogenative coupling allyl acetate; departure chirally metal reagent addition crystallog; aldehyde enantioselective iridium catalyzed carbonyl allylation.

Under the conditions of transfer hydrogenation employing an iridium catalyst generated in situ from [Ir(cod)Cl]2, chiral phosphine ligand (R)-BINAP or (R)-Cl,MeO-BIPHEP, and m-nitrobenzoic acid, allyl acetate couples to allylic, aliphatic, or benzylic alcs. to furnish products of carbonyl allylation with exceptional levels of asym. induction. The very same set of optically enriched carbonyl allylation products are accessible from enals , aliphatic aldehydes , and aryl aldehydes, using iridium catalysts ligated by (-)-TMBTP or (R)-Cl,MeO-BIPHEP under identical conditions, but employing isopropanol as a hydrogen donor. A catalytically active cyclometallated complex V, which arises upon ortho-C-H insertion of iridium onto m-nitrobenzoic acid, was characterized by single-crystal x-ray diffraction. The results of isotopic labeling are consistent with intervention of sym. iridium π-allyl intermediates or rapid interconversion of σ-allyl haptomers through the agency of a sym. π-allyl. Competition experiments demonstrate rapid and reversible hydrogenation-dehydrogenation of the carbonyl partner in advance of C-C coupling. However, the coupling products, which are homoallylic alcs., experience very little erosion of optical purity by way of redox equilibration under the coupling conditions, although isopropanol, a secondary alc., may serve as terminal reductant. A plausible catalytic mechanism accounting for these observations is proposed, along with a stereochem. model that accounts for the observed sense of absolute stereoinduction. This protocol for asym. carbonyl allylation transcends the barriers imposed by oxidation level and the use of preformed allyl metal reagents.

Journal of the American Chemical Society published new progress about Alcohols, homoallylic Role: SPN (Synthetic Preparation), PREP (Preparation). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Application In Synthesis 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

Cheng, Hang; Qin, Yiming; Dhillon, Rashpal; Dowell, James; Denu, John M.; Pamenter, Matthew E. published the artcile< Metabolomic Analysis of Carbohydrate and Amino Acid Changes Induced by Hypoxia in Naked Mole-Rat Brain and Liver>, 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 brain liver carbohydrate amino acid hypoxia metabolomics; AMP; aspartic acid; coenzyme; dopamine; glutamate; glutamine; glutathione; glycogen; pentose phosphate pathway.

Hypoxia poses a major physiol. challenge for mammals and has significant impacts on cellular and systemic metabolism As with many other small rodents, naked mole-rats (NMRs; Heterocephalus glaber), who are among the most hypoxia-tolerant mammals, respond to hypoxia by suppressing energy demand (i.e., through a reduction in metabolic rate mediated by a variety of cell- and tissue-level strategies), and altering metabolic fuel use to rely primarily on carbohydrates. However, little is known regarding specific metabolite changes that underlie these responses. We hypothesized that NMR tissues utilize multiple strategies in responding to acute hypoxia, including the modulation of signalling pathways to reduce anabolism and reprogram carbohydrate metabolism To address this question, we evaluated changes of 64 metabolites in NMR brain and liver following in vivo hypoxia exposure (7% O2, 4 h). We also examined changes in matched tissues from similarly treated hypoxia-intolerant mice. We report that, following exposure to in vivo hypoxia: (1) phenylalanine, tyrosine and tryptophan anabolism are suppressed both in NMR brain and liver; (2) carbohydrate metabolism is reprogramed in NMR brain and liver, but in a divergent manner; (3) redox state is significantly altered in NMR brain; and (4) the AMP/ATP ratio is elevated in liver. Overall, our results suggest that hypoxia induces significant metabolic remodelling in NMR brain and liver via alterations of multiple metabolic pathways.

Metabolites published new progress about Amino acids Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 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

Xu, Jian-Lin; Xu, Zhe-Yuan; Wang, Zi-Lu; Ma, Wei-Wei; Sun, Xin-Yue; Fu, Yao; Xu, Yun-He published the artcile< Copper-Catalyzed Regiodivergent and Enantioselective Hydrosilylation of Allenes>, Reference of 139139-93-8, the main research area is allene preparation copper catalyzed regiodivergent enantioselective hydrosilylation; biphenylallyl phenylsilane chiral preparation crystal structure; mol structure biphenylallyl phenylsilane chiral; allylsilane linear branched chiral enantioselective preparation.

A Cu-catalyzed regiodivergent hydrosilylation of a wide range of simple allenes is reported. Linear and branched allylsilanes were formed by judicious choice of solvents. Also, branched allylsilanes were obtained with high enantioselectivity (up to 97% enantiomeric excess) with the aid of a C2-sym. bisphosphine ligand in the unprecedented asym. allene hydrosilylation.

Journal of the American Chemical Society published new progress about Allenes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Reference 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

Suzuki, Yuta; Nemoto, Tetsuhiro; Kakugawa, Kazumi; Hamajima, Akinari; Hamada, Yasumasa published the artcile< Asymmetric synthesis of chiral 9,10-dihydrophenanthrenes using Pd-catalyzed asymmetric intramolecular 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 dihydrophenanthrene derivative enantioselective synthesis; phenol Friedel Crafts allylic alkylation Pd catalyst.

We developed a novel asym. synthetic method for multisubstituted 9,10-dihydrophenanthrenes based on the Pd-catalyzed asym. intramol. Friedel-Crafts allylic alkylation of phenols, which produces 10-vinyl or 10-isopropenyl chiral 9,10-dihydrophenanthrene derivatives e. g., I in high yield with up to 94% ee.

Organic Letters published new progress about Aryl bromides 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, 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

Trost, Barry M.; Lehr, Konrad; Michaelis, David J.; Xu, Jiayi; Buckl, Andreas K. published the artcile< Palladium-Catalyzed Asymmetric Allylic Alkylation of 2-Acylimidazoles as Ester Enolate Equivalents>, HPLC of Formula: 152140-65-3, the main research area is cetiedil stereoselective preparation; acylimidazole stereoselective preparation; imidazolyl allyl enol carbonate enantioselective allylic alkylation palladium catalyst; unsaturated carbonyl compound preparation acylimidazole hydrolysis.

A broad range of highly enantioenriched 2-acylimidazoles, e.g. I, are synthesized by palladium-catalyzed decarboxylative asym. allylic alkylation (DAAA) of 2-imidazolo-substituted enol carbonates, e.g. II. The enantioenriched 2-acylimidazole products can easily be converted to the corresponding carboxylic acid (e.g. III), ester, amide, and ketone derivatives with complete retention of the enantiopurity. The synthetic utility of this new method is demonstrated in the short, efficient synthesis of cetiedil IV.

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

Ogaki, Shuichiro; Shibata, Yu; Noguchi, Keiichi; Tanaka, Ken published the artcile< Enantioselective Synthesis of Axially Chiral Hydroxy Carboxylic Acid Derivatives by Rhodium-Catalyzed [2 + 2 + 2] Cycloaddition>, Application of C44H40P2, the main research area is naphthalenepropynoic acid derivative diyne chiral rhodium bisphosphine catalyst cycloaddition; arylnaphthalene hydroxy carboxylic acid derivative regioselective stereoselective preparation; axially chiral arylnaphthalene regioselective stereoselective preparation.

Axially chiral hydroxy carboxylic acid derivatives were successfully synthesized with high yields and ee values by the cationic rhodium(I)/axially chiral biaryl bisphosphine complex-catalyzed enantioselective [2+2+2] cycloaddition of diynes with naphthalenepropynoic acid derivatives Axially chiral hydroxy and dihydroxy carboxylic acid derivatives, bearing the aryl group at the ortho-position of the alkoxycarbonyl group, were also synthesized with high regio- and enantioselectivity.

Journal of Organic Chemistry published new progress about Alkadiynes Role: RCT (Reactant), RACT (Reactant or Reagent) (derivatives). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Application of 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

De, Subhadip; Das, Mrinal Kanti; Roy, Avishek; Bisai, Alakesh published the artcile< Synthesis of 2-Oxindoles Sharing Vicinal All-Carbon Quaternary Stereocenters via Organocatalytic Aldol Reaction>, Name: N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide], the main research area is oxindole preparation organocatalytic enantioselective aldol; folicanthine formal total synthesis organocatalytic enantioselective aldol.

An organocatalytic enantioselective aldol reaction using paraformaldehyde as the C1-unit has been developed for the synthesis of 2-oxindoles sharing vicinal all-carbon quaternary stereocenters. The methodol. is eventually employed in the formal total synthesis of (+)-folicanthine (I).

Journal of Organic Chemistry published new progress about Aldol addition catalysts, stereoselective. 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

Ruchelman, Alexander L.; Connolly, Terrence J. published the artcile< Enantioselective synthesis of the apremilast aminosulfone using catalytic asymmetric hydrogenation>, SDS of cas: 277306-29-3, the main research area is enantioselective apremilast aminosulfone catalytic asym hydrogenation.

Celgene’s Otezla (apremilast) is the first and only PDE4 inhibitor approved by the US FDA for the treatment of plaque psoriasis and psoriatic arthritis. Apremilast has been historically prepared via resolution to obtain the enantioenriched aminosulfone intermediate. Herein we have investigated the use of catalytic asym. hydrogenation for the enantioselective synthesis of the key aminosulfone intermediate in order to identify a higher yielding and greener synthesis route. Asym. reduction of the enamine 3-EtO-4-MeOC6H3C(NH2):CHSO2Me and the ketone 3-EtO-4-MeOC6H3COCH2SO2Me both proceeded with high selectivities, generating their resp. products with >95% ee.

Tetrahedron: Asymmetry published new progress about Enantioselective synthesis. 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, SDS of cas: 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