Category: chiral-phosphine-ligands

Trost, Barry M.; Xu, Jiayi; Schmidt, Thomas published the artcile< Palladium-Catalyzed Decarboxylative Asymmetric Allylic Alkylation of Enol Carbonates>, Application of C54H42N2O2P2, the main research area is allyl enol carbonate enantioselective regioselective decarboxylative allylic alkylation palladium; ketone homoallylic asym synthesis.

Palladium-catalyzed decarboxylative asym. allylic alkylation (DAAA) of allyl enol carbonates as a highly chemo-, regio-, and enantioselective process for the synthesis of ketones bearing either a quaternary or a tertiary α-stereogenic center has been investigated in detail. Chiral dibenzobarrelene-based diphosphine ligand was found to be optimal in the DAAA of a broad scope of cyclic and acyclic ketones including simple aliphatic ketones with more than one enolizable proton. The allyl moiety of the carbonates has been extended to a variety of cyclic or acyclic disubstituted allyl groups. The mechanistic studies revealed that, similar to the direct allylation of lithium enolates, the DAAA reaction proceeds through an “”outer sphere”” SN2 type of attack on the π-allylpalladium complex by the enolate. An important difference between the DAAA reaction and the direct allylation of lithium enolates is that in the DAAA reaction, the nucleophile and the electrophile were generated simultaneously. Since the π-allylpalladium cation must serve as the counterion for the enolate, the enolate probably exists as a tight-ion-pair. This largely prevents the common side reactions of enolates associated with the equilibrium between different enolates. The much milder reaction conditions as well as the much broader substrate scope also represent the advantages of the DAAA reaction over the direct allylation of preformed metal enolates.

Journal of the American Chemical Societypublished new progress about Allylic alkylation catalysts, stereoselective. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Application of C54H42N2O2P2.

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

Tsuchikama, Kyoji; Yoshinami, Yusuke; Shibata, Takanori published the artcile< Rhodium-complex-catalyzed [2+2+2] cycloaddition of diynes and carbonyl compounds>, Synthetic Route of 139139-93-8, the main research area is diyne carbonyl stereoselective cycloaddition rhodium BINAP catalyst; hydropyran stereoselective preparation electrocyclic ring opening; cyclopentene stereoselective preparation; hydropyrrole stereoselective preparation; hydrofuran stereoselective preparation.

A Rh-BINAP complex was used to catalyze the hetero-[2+2+2] cycloaddition of sym. 1,6-diynes and carbonyl moiety of keto esters, a diketone, and an aldehyde to give bicyclic α-pyrans, which were readily transformed into monocyclic compounds via the following electrocyclic ring opening. In the reaction of an unsym. 1,6-diyne and a 1,7-diyne, α-pyrans with a quaternary carbon stereocenter were obtained in moderate to excellent ee using a chiral rhodium catalyst.

Synlettpublished new progress about Alkadiynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Synthetic Route 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

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

Li, Min; Li, Bin; Xia, Hong-Feng; Ye, Danru; Wu, Jing; Shi, Yifeng published the artcile< Mesoporous silica KIT-6 supported superparamagnetic CuFe2O4 nanoparticles for catalytic asymmetric hydrosilylation of ketones in air>, Application of C44H40P2, the main research area is silica copper iron oxide nanoparticle catalyst ketone asym hydrosilylation.

A diverse range of prochiral ketones were reduced in air with high yields and good-to-excellent enantioselectivities (up to 97% ee) in the presence of a heterogeneous catalyst system, which was in situ formed from catalytic amounts of superparamagnetic CuFe2O4 nanoparticles supported on mesoporous silica KIT-6 and non-racemic dipyridylphosphine ligand, the stoichiometric hydride donor polymethylhydrosiloxane (PMHS) as well as certain amounts of additives. The magnetically separable catalysts could be efficiently reused 4 times without apparent loss of both the activity and enantioselectivity.

Green Chemistrypublished new progress about Catalyst supports. 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

Trost, Barry M.; Xu, Jiayi; Schmidt, Thomas published the artcile< Ligand Controlled Highly Regio- and Enantioselective Synthesis of α-Acyloxyketones by Palladium-Catalyzed Allylic Alkylation of 1,2-Enediol Carbonates>, Application In Synthesis of 152140-65-3, the main research area is enediol carbonate allyl alkylation palladium catalysis ligand; acetoxyketone asym preparation.

The palladium-catalyzed decarboxylative asym. allylic alkylation of allyl 1,2-enediol carbonates can decompose to either α-hydroxyketones or α-hydroxyaldehydes. The product distribution is largely controlled by the ligand. Using Lnaph in DME the ketone product is obtained in good to excellent yields and high enantiomeric excesses. The reaction proceeds under extremely mild conditions and was tested with a broad range of ester substrates. Besides commonly used protection groups, such as OAc and OPiv, a more functionalized group, Me but-2-enoyl, is also used that can eventually afford other synthetically interesting structures.

Journal of the American Chemical Societypublished new progress about Alkyl aryl ketones 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, Application In Synthesis of 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

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