Category: 325168-88-5

Driver, Tom G.; Harris, Jason R.; Woerpel, K. A. published the artcile< Kinetic Resolution of Hydroperoxides with Enantiopure Phosphines: Preparation of Enantioenriched Tertiary Hydroperoxides>, Formula: C48H50P2, 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, Formula: 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

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>, Recommanded Product: (S)-(+)-4,12-Bis(di(3,5-xylyl)phosphino)-[2.2]-paracyclophane, 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, 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

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>, Application In Synthesis 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, Application In Synthesis 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

Mullen, Charles A.; Campbell, Alison N.; Gagne, Michel R. published the artcile< Asymmetric oxidative cation/olefin cyclization of polyenes: evidence for reversible cascade cyclization>, Quality Control of 325168-88-5, the main research area is polyenol xylylphanephos platinum silver enantioselectively diastereoselectively regioselectively oxidative cyclization; fused oxygen containing heterocycle stereoselective preparation reaction determining step.

Activation of [(xylyl-phanephos)PtCl2] by silver generates an electrophilic catalyst that can enantioselectively, diastereoselectively, and regioselectively promote the stereospecific oxidative cyclization of polyene-ols. Mechanistic experiments indicate that the stereochem.-determining step is not the initial cyclization step, but rather a subsequent step in the reaction.

Angewandte Chemie, International Editionpublished new progress about Alkenyl alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Quality Control 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

Felix, Ryan J.; Weber, Dieter; Gutierrez, Osvaldo; Tantillo, Dean J.; Gagne, Michel R. published the artcile< A gold-catalysed enantioselective Cope rearrangement of achiral 1,5-dienes>, HPLC of Formula: 325168-88-5, the main research area is gold catalysis enantioselective cope rearrangement achiral dienes.

Since the discovery of the Cope rearrangement in the 1940s, no asym. variant of the rearrangement of achiral 1,5-dienes has emerged, despite the successes that have been achieved with its heteroatom variants (Claisen, aza-Cope, and so on). This article reports the first example of an enantioselective Cope reaction that starts from an achiral diene. The new gold(I) catalyst derived from double Cl–abstraction of ((S)-3,5-xylyl-PHANEPHOS(AuCl)2), has been developed for the sigmatropic rearrangement of alkenyl-methylenecyclopropanes. The reaction proceeds at low temperature and the synthetically useful vinylcyclopropane products are obtained in high yield and enantioselectivity. D. functional theory calculations predict that: (1) the reaction proceeds via a cyclic carbenium ion intermediate, (2) the relief of strain in the methylenecyclopropane moiety provides the thermodn. driving force for the rearrangement and (3) metal complexation of the transition-state structure lowers the rearrangement barriers.

Nature Chemistrypublished new progress about [3,3]-Sigmatropic rearrangement. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, HPLC of Formula: 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

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>, Recommanded Product: (S)-(+)-4,12-Bis(di(3,5-xylyl)phosphino)-[2.2]-paracyclophane, 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 Chemistrypublished 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, 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

Driver, Tom G.; Harris, Jason R.; Woerpel, K. A. published the artcile< Kinetic Resolution of Hydroperoxides with Enantiopure Phosphines: Preparation of Enantioenriched Tertiary Hydroperoxides>, Product Details of C48H50P2, 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 Societypublished 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, Product Details 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