Category: 325168-88-5

Bandini, Marco; Gualandi, Andrea; Monari, Magda; Romaniello, Alessandro; Savoia, Diego; Tragni, Michele published the artcile< Allylic alcohols: Valuable synthetic equivalents of non-activated alkenes in gold-catalyzed enantioselective alkylation of indoles>, Reference of 325168-88-5, the main research area is allylic alc tethered indole derivative preparation; chiral ligand gold catalyzed intramol allylic alkylation indole derivative; tetrahydrocarbazole derivative stereoselective preparation; tetrahydrocarboline derivative stereoselective preparation.

The recent booming of gold catalysis has demonstrated that unprecedented transformations can be realized in a highly selective manner. Moreover, due to the growing availability of chiral organic ligands, gold-catalysis can be considered as one of most dynamic hot spots in asym. synthesis. However, in this context, the use of non-activated olefinic C-C double bonds is still largely unexplored due to the intrinsic inertness of C=C (respect to allenes and alkynes) in taking part in nucleophilic additions assisted by π-electrophilic activations. Allylic alcs. have been demonstrated to be feasible “”surrogates”” of non-activated alkenes for the enantioselective allylic alkylation of indoles catalyzed by chiral gold(I) complexes. In this investigation, a full account addressing efficiency and substrate scope of such a process is presented. The products, tetrahydrocarbazoles or tetrahydro-β-carbolines, are obtained in moderate to good yields and 40-86% ee from the corresponding Z-allylic alc.-containing substrates, while the E isomers are unreactive.

Journal of Organometallic Chemistry published new progress about Allylic alcohols Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Reference of 325168-88-5.

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

Cederbaum, Fredrik; Lamberth, Clemens; Malan, Christophe; Naud, Fred; Spindler, Felix; Studer, Martin; Blaser, Hans-Ulrich published the artcile< Synthesis of substituted mandelic acid derivatives via enantioselective hydrogenation: Homogeneous versus heterogeneous catalysis>, Electric Literature of 325168-88-5, the main research area is stereoselective hydrogenation chlorophenylglyoxylate ruthenium homogeneous heterogeneous catalyst; chloromandelate stereoselective preparation ruthenium homogeneous heterogeneous catalyst; platinum cinchona catalyst stereoselective hydrogenation chlorophenylglyoxylate.

An extensive screening of both homogeneous and heterogeneous catalysts was carried out for the enantioselective hydrogenation of p-chlorophenylglyoxylic acid derivatives For p-chlorophenylglyoxylic amides only homogeneous Rh-diphosphine complexes gave satisfactory results, ees up to 87% were observed for the cy-oxo-pronop ligand. For Me p-chlorophenylglyoxylate both a homogeneous as well as a heterogeneous catalyst performed with ees >90%. A Pt catalyst modified with cinchona derivatives achieved 93% ee for the (R)- and 87% ee for the (S)-Me p-chloromandelate. A Ru-MeObiphep catalyst also reached 93% ee with TONs up to 4000 and TOFs up to 210 h-1. For all catalytic systems the effects of the metal, the nature of the chiral auxiliary and the solvent as well as of the reaction conditions were investigated. The homogeneous process was scaled up to the kg scale and the enantiomeric purity of the product was enhanced to >99% ee by two recrystallizations of the free p-chlorophenylmandelic acid.

Advanced Synthesis & Catalysis published new progress about Catalysts. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Electric Literature of 325168-88-5.

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

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>, Computed Properties of 325168-88-5, 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).

Tetrahedron: Asymmetry published new progress about Allylic alkylation. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Computed Properties of 325168-88-5.

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

Sarcher, Christian; Luehl, Anja; Falk, Florian C.; Lebedkin, Sergei; Kuehn, Michael; Wang, Cong; Paradies, Jan; Kappes, Manfred M.; Klopper, Wim; Roesky, Peter W. published the artcile< [2.2]Paracyclophanediyldiphosphane Complexes of Gold>, Electric Literature of 325168-88-5, the main research area is paracyclophanediyl diphosphine gold complex preparation crystal mol structure; alkyne hydroamination catalyst paracyclophanediyl diphosphine gold chloride complex; phosphorescence paracyclophanediyl diphosphine gold chloride complex.

Authors have prepared digold(I) complexes with the rigid-backbone diphosphine ligands PhanePhos, xyl-PhanePhos, and Ph2-GemPhos. All complexes were characterized by single-crystal x-ray diffraction, NMR, IR, Raman, and photoluminescence (PL) spectroscopy. [PhanePhos(AuCl)2] and [GemPhos(AuCl)2] show a very similar ligand scaffold, but different (aurophilic vs. nonaurophilic) intramol. Au-Au distances. Absorption and PL spectra of both compounds are quite similar. Theor. investigations reveal that the excited states are of different character (i.e., influenced by the Au-Au contacts). The resp. transition energies, however, lie close to each other, thus resulting in similar exptl. spectra. The gold atoms appear to produce a significant heavy-atom effect in the electronic relaxation dynamics. Thus, [PhanePhos(AuCl)2] and [GemPhos(AuCl)2] both show bright-green millisecond-long phosphorescence at low temperatures, although the latter is quenched at ambient temperature [PhanePhos(AuCl)2] and [GemPhos(AuCl)2] were also used as catalysts in the intra- and intermol. hydroamination of alkynes. Good to quant. conversions on a reasonable time scale were observed The overall performance of these catalysts in the studied reactions was similar, showing that Au-Au contacts do not have a major influence on the catalytic performance.

European Journal of Inorganic Chemistry published new progress about Alkynes Role: RCT (Reactant), RACT (Reactant or Reagent). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Electric Literature of 325168-88-5.

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

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.

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.

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

Rasson, Corentin; Riant, Olivier published the artcile< Copper(I) Diphosphine Bifluoride Complexes as Efficient Preactivated Catalysts for Nucleophilic Addition on Unsaturated Functional Groups>, Category: chiral-phosphine-ligands, the main research area is copper diphosphine bifluoride complex catalyst preparation nucleophilic addition; nucleophilic copper addition pronucleophile aldehyde ketone.

Herein we report the synthesis of a family of copper(I) diphosphine bifluoride complexes, their characterization, and their use as efficient preactivated catalysts for nucleophilic copper addition of pronucleophiles on unsaturations. Their use as mechanistic probes is also highlighted by the identification of two copper deuterides.

Organic Process Research & Development published new progress about Allylation catalysts, stereoselective. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Category: chiral-phosphine-ligands.

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

Driver, Tom G.; Harris, Jason R.; Woerpel, K. A. published the artcile< Kinetic Resolution of Hydroperoxides with Enantiopure Phosphines: Preparation of Enantioenriched Tertiary Hydroperoxides>, Recommanded Product: (S)-(+)-4,12-Bis(di(3,5-xylyl)phosphino)-[2.2]-paracyclophane, the main research area is hydroperoxide tertiary reductive kinetic resolution cyclophane phosphine.

An efficient reductive kinetic resolution strategy capable of accessing optically active tertiary hydroperoxides R1R2C(Ph)OOH (R1 = H, Me; R2 = Et, n-Pr, Me2CH, cyclohexyl, Me3CSiMe2OCH2, etc.) is reported. Readily accessible tertiary hydroperoxides are resolved with com. available (R)- or (S)-xylyl-PHANEPHOS with selectivity factors as large as 37. The resulting bis(phosphine oxide) can be recycled in high yields. The isolated mono(phosphine oxide) intermediate resolved hydroperoxides with the same selectivity as the parent bis-phosphine.

Journal of the American Chemical Society published new progress about Hydroperoxides Role: PUR (Purification or Recovery), RCT (Reactant), SPN (Synthetic Preparation), PREP (Preparation), RACT (Reactant or Reagent). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Recommanded Product: (S)-(+)-4,12-Bis(di(3,5-xylyl)phosphino)-[2.2]-paracyclophane.

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

Cobley, Christopher J.; Lennon, Ian C.; Praquin, Celine; Zanotti-Gerosa, Antonio; Appell, Robert B.; Goralski, Christian T.; Sutterer, Angela C. published the artcile< Highly Efficient Asymmetric Hydrogenation of 2-Methylenesuccinamic Acid Using a Rh-DuPHOS Catalyst>, Category: chiral-phosphine-ligands, the main research area is methylsuccinamic acid enantioselective preparation; methylenesuccinamic acid preparation; asym hydrogenation methylenesuccinamic acid rhodium DuPHOS catalyst; chloride residue methylenesuccinamic acid hindrance asym hydrogenation.

Nonracemic 2-methylsuccinamic acid HO2CCHMeCH2CONH2 is prepared efficiently in two steps from itaconic anhydride using an asym. hydrogenation as the key step. Ring opening of itaconic anhydride with an aqueous solution of ammonium hydroxide followed by neutralization with sulfuric acid yields 2-methylenesuccinamic acid HO2CC(:CH2)CH2CONH2 in 53% yield after recrystallization to remove 3-methylenesuccinamic acid present as an impurity. The use of hydrochloric acid in the neutralization step as in previous procedures leads to the presence of chloride residues in the product; hydrogenation of 2-methylenesuccinamic acid containing chloride residues requires higher loadings of catalyst and longer reaction times, although the enantiomeric excess of the 2-methylsuccinamic acid produced is unaffected. Using 0.001 mol% {[(S,S)-Et-DuPHOS]Rh(COD)}+BF4- as the precatalyst for hydrogenation of 2-methylenesuccinamic acid in methanol under 140 atm of hydrogen at 45°, (R)-2-methylsuccinamic acid is obtained in 96% ee. Single-crystal digestion of (R)-2-methylsuccinamic acid obtained from the hydrogenation yields (R)-2-methylsuccinamic acid in >99.5% ee and 77% conversion containing less than 1 ppm rhodium.

Organic Process Research & Development published new progress about Hydrogenation catalysts, stereoselective. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Category: chiral-phosphine-ligands.

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

Grasa, Gabriela A.; Zanotti-Gerosa, Antonio; Ghosh, Shyamali; Teleha, Christopher A.; Kinney, William A.; Maryanoff, Bruce E. published the artcile< Efficient, enantioselective synthesis of a β,β-disubstituted carboxylic acid by Ru-XylPhanePhos-catalyzed asymmetric hydrogenation>, Reference of 325168-88-5, the main research area is piperidinebutenoic acid quinolinyl stereoselective reduction phanephos ruthenium catalyst.

Enantioselective preparation of a key αvβ3 integrin antagonist intermediate, (3S)-3-(quinolin-3-yl)-4-(1-tert.-butoxycarbonylpiperidin-4-yl)butanoic acid, was accomplished via catalytic asym. hydrogenation of the corresponding but-2-enoic acid. The successful application of a Ru-(R)-XylPhanePhos catalyst to this type of substrate is unprecedented. In situ NMR experiments of pre-catalyst formation/activation by CH3CO2H, and reaction parameter modification, revealed that [Ru(COD)(CF3CO2)2]2/(R)-XylPhanePhos is a highly active and efficient catalytic system.

Tetrahedron Letters published new progress about Hydrogenation catalysts, stereoselective. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Reference of 325168-88-5.

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

Rasson, Corentin; Riant, Olivier published the artcile< Copper(I) Diphosphine Bifluoride Complexes as Efficient Preactivated Catalysts for Nucleophilic Addition on Unsaturated Functional Groups>, Category: chiral-phosphine-ligands, the main research area is copper diphosphine bifluoride complex catalyst preparation nucleophilic addition; nucleophilic copper addition pronucleophile aldehyde ketone.

Herein we report the synthesis of a family of copper(I) diphosphine bifluoride complexes, their characterization, and their use as efficient preactivated catalysts for nucleophilic copper addition of pronucleophiles on unsaturations. Their use as mechanistic probes is also highlighted by the identification of two copper deuterides.

Organic Process Research & Development published new progress about Allylation catalysts, stereoselective. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Category: chiral-phosphine-ligands.

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