Category: 277306-29-3

Lipshutz, Bruce H.; Lee, Ching-Tien; Taft, Benjamin R. published the artcile< A conjugate reduction pathway to chiral silanes using CuH>, Category: chiral-phosphine-ligands, the main research area is ester carboxylic silylated chiral preparation asym reduction hydrosilylation enoate; copper hydride ferrocenylphosphine catalyst asym reduction hydrosilylation enoate; silane carboxyalkyl chiral preparation asym reduction silyl enoate.

Asym. reduction of β-silyl α,β-unsaturated esters was achieved by CuH/(R,S)-PPF-P(tBu)2 reagent, affording chiral β-silylated arylalkanoate esters. β-Silyl enoates (Z)- and (E)-PhMe2SiCR:CHCO2R1 [(Z)-2, (E)-2, resp.] were prepared by Peterson or Horner-Wadsworth-Emmons olefination, resp., of the corresponding acylsilanes PhMe2SiCOR. The compounds 2 were reduced by CuH-catalyzed conjugate hydrosilylation by polymethylhydrosiloxane in the presence of chiral ferrocenylphosphine, (R,S)-1-[1-(di-tert-butylphosphino)ethyl]-2-diphenylphosphinoferrocene (1). Exptl. details concerning asym. 1,4-reduction of β-silylated-β,β-disubstituted enoates catalyzed by CuH are described.

Synthesispublished new progress about Esters, α,β-unsaturated Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, 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

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>, Recommanded Product: (2S)-1-[(1S)-1-[Bis(1,1-dimethylethyl)phosphino]ethyl]-2-(diphenylphosphino)ferrocene, 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 %).

Journal of the American Chemical Societypublished 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, Recommanded Product: (2S)-1-[(1S)-1-[Bis(1,1-dimethylethyl)phosphino]ethyl]-2-(diphenylphosphino)ferrocene.

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

Lipshutz, Bruce H.; Amorelli, Benjamin; Unger, John B. published the artcile< CuH-Catalyzed Enantioselective Intramolecular Reductive Aldol Reactions Generating Three New Contiguous Asymmetric Stereocenters>, Computed Properties of 277306-29-3, the main research area is unsaturated ketone copper enantioselective intramol reductive aldol chiral phosphine; cycloalkanol stereoselective preparation; enantioselective intramol reductive aldol catalyst copper chiral phosphine.

Treatment of β,β-disubstituted-α,β-unsaturated ketones, e.g., I, bearing a ketone residue with in situ generated, catalytic CuH ligated by a nonracemic ligand leads to cycloalkanols, e.g., II, with three newly created adjacent chiral centers. Excellent de’s and ee’s are obtained for several examples studied.

Journal of the American Chemical Societypublished new progress about Aldol condensation catalysts, stereoselective (intramol.). 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, Computed Properties of 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

Wiest, Johannes M.; Conner, Michael L.; Brown, M. Kevin published the artcile< Synthesis of (-)-Hebelophyllene E: An Entry to Geminal Dimethyl-Cyclobutanes by [2+2] Cycloaddition of Alkenes and Allenoates>, Category: chiral-phosphine-ligands, the main research area is hebelophyllene E sesquiterpene lactone preparation relative configuration; alkene catalytic enantioselective cycloaddition allenoate; chiral geminal dimethylcyclobutane derivatives preparation diastereoselective reduction; oxazaborolidine catalyst enantioselective cycloaddition alkene allenoate; cycloaddition; enantioselectivity; natural products; small ring systems; total synthesis.

The first synthesis of hebelophyllene E (I) is presented, along with assignment of its previously unknown relative configuration through synthesis of epi-ent-hebelophyllene E. Development of a catalytic enantioselective [2+2] cycloaddition of alkenes and allenoates provides access to the required chiral geminal dimethylcyclobutanes. Key to its success is the identification of a novel oxazaborolidine catalyst which promotes the cycloaddition in high enantioselectivities with good functional-group tolerance (9 examples, up to 97:3 e.r.). Thus, a late-stage cycloaddition using a fully functionalized alkene, followed by a diastereoselective reduction allows a concise entry to this class of natural products.

Angewandte Chemie, International Editionpublished new progress about [2+2] Cycloaddition reaction (enantioselective, of alkenes and allenoates). 277306-29-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C32H40FeP2, 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