October 2022 | Page 25 of 44 | Chiral phosphine ligands

Yoshida, Mariko’s team published research in Tetrahedron: Asymmetry in 2012-06-30 | 152140-65-3

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].

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).

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’s team published research in Journal of Chemical Thermodynamics in 2019-01-31 | 606-68-8

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.

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.

Kaiser, Thomas M’s team published research in European Journal of Organic Chemistry in 2013 | 152140-65-3

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.

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.

Alame, Mohamad’s team published research in Advanced Synthesis & Catalysis in 2008-04-30 | 325168-88-5

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.

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.

Starkov, Pavel’s team published research in Journal of the American Chemical Society in 2017-07-19 | 152140-65-3

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].

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.

Lautens, Mark’s team published research in Journal of the American Chemical Society in 2003-12-03 | 277306-29-3

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.

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 %).

Tsukamoto, Hirokazu’s team published research in Journal of Combinatorial Chemistry in 2006-06-30 | 277306-29-3

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.

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.

Ludvik, J’s team published research in Analytica Chimica Acta in 1988-06-15 | 606-68-8

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.

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.

Hato, Yoshio’s team published research in Journal of Organic Chemistry in 2016-09-02 | 139139-93-8

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

Hato, Yoshio; Oonishi, Yoshihiro; Yamamoto, Yasunori; Nakajima, Kiyohiko; Sato, Yoshihiro published the artcile< Stereoselective Construction of Spiro-Fused Tricyclic Frameworks by Sequential Reaction of Enynes, Imines, and Diazoalkenes with Rh(I) and Rh(II) Catalysts>, Application of C44H40P2, the main research area is stereoselective spiro fused tricyclic compound; rhodium catalyst imine tethered enyne reaction diazoalkene.

Stereoselective construction of spiro-fused tricyclic compounds from enynes having a tethered imine with diazoalkenes was achieved by Rh(I)- and Rh(II)-catalyzed sequential reactions. This method consists of three reactions, i.e., Rh(I)-catalyzed cyclization of enynes with a tethered imine, Rh(II)-catalyzed cyclopropanation with diazoalkenes, and Cope rearrangement. Notably, the sequential reactions can be operated in one pot, in which Rh(I) and Rh(II) catalysts work in relay without any serious catalyst deactivation to afford the spirocycles in a stereoselective manner.

Kusama, Tomoya’s team published research in Frontiers in Chemistry (Lausanne, Switzerland) in 2021 | 139139-93-8

Frontiers in Chemistry (Lausanne, Switzerland) published new progress about Crystallinity. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, COA of Formula: C44H40P2.

Kusama, Tomoya; Hirata, Shuzo published the artcile< Thermo-reversible persistent phosphorescence modulation reveals the large contribution made by rigidity to the suppression of endothermic intermolecular triplet quenching>, COA of Formula: C44H40P2, the main research area is diphenylphosphino binaphthyl triplet energy phosphorescence; diffusion constant; nonradiative deactivation; persistent room-temperature phosphorescence; phase change; reorganization energy; triplet quenching.

The suppression of thermally driven triplet deactivation is crucial for efficient persistent room-temperature phosphorescence (pRTP). However, the mechanism by which triplet deactivation occurs in metal-free mol. solids at room temperature (RT) remains unclear. Herein, we report a large pRTP intensity change in a mol. guest that depended on the reversible amorphous-crystal phase change in the mol. host, and we confirm the large contribution made by the rigidity of the host in suppressing intermol. triplet quenching in the guest. (S)-(-)-2,2′-Bis(diphenylphosphino)-1,1′- binaphthyl ((S)-BINAP) was doped as a guest into a highly purified (S)- bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl ((S)-H8-BINAP) host. It was possible to reversibly form the amorphous and crystalline states of the solid by cooling to RT from various temperatures The RTP yield (Φp) originating from the (S)-BINAP was 6.7% in the crystalline state of the (S)-H8-BINAP host, whereas it decreased to 0.31% in the amorphous state. Arrhenius plots showing the rate of nonradiative deactivation from the lowest triplet excited state (T1) of the amorphous and crystalline solids indicated that the large difference in Φp between the crystalline and amorphous states was mostly due to the discrepancy in the magnitude of quenching of intermol. triplet energy transfer from the (S)-BINAP guest to the (S)-H8-BINAP host. Controlled analyses of the T1 energy of the guest and host, and of the reorganization energy of the intermol. triplet energy transfer from the guest to the host, confirmed that the large difference in intermol. triplet quenching was due to the discrepancy in the magnitude of the diffusion constant of the (S)-H8-BINAP host between its amorphous and crystalline states. Quantification of both the T1 energy and the diffusion constant of mols. used in solid materials is crucial for a meaningful discussion of the intermol. triplet deactivation of various metal-free solid materials.