Category: chiral-phosphine-ligands

Trost, Barry M.; Thaisrivongs, David A. published the artcile< Strategy for Employing Unstabilized Nucleophiles in Palladium-Catalyzed Asymmetric Allylic Alkylations>, Recommanded Product: N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide], the main research area is strategy employing unstabilized nucleophile palladium catalyzed asym allylic alkylation.

The authors report a strategy for the employment of highly unstabilized anions in palladium-catalyzed asym. allylic alkylations (AAA). The hard 2-methylpyridyl nucleophiles studied are first reacted in situ with BF3•OEt2; subsequent deprotonation of the resulting complexes with LiHMDS affords soft anions that are competent nucleophiles in AAA reactions. The reaction is selective for the 2-position of methylpyridines and tolerates bulky aryl and alkyl substitution at the 3-, 4-, and 5-positions. Studies into the reaction mechanism demonstrate that the configuration of the allylic stereocenter is retained, consistent with the canonical outer sphere mechanism invoked for palladium-catalyzed allylic substitution processes of stabilized anions.

Journal of the American Chemical Society published new progress about Allylic alkylation catalysts, stereoselective. 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Recommanded Product: N,N’-(11R,12R)-(9,10-Dihydro-9,10-ethanoanthracene-11,12-diyl)bis[2-(diphenylphosphino)benzamide].

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

Fernandez, Marti; Parera, Magda; Parella, Teodor; Lledo, Agusti; Le Bras, Jean; Muzart, Jacques; Pla-Quintana, Anna; Roglans, Anna published the artcile< Rhodium-Catalyzed [2+2+2] Cycloadditions of Diynes with Morita-Baylis-Hillman Adducts: A Stereoselective Entry to Densely Functionalized Cyclohexadiene Scaffolds>, COA of Formula: C44H40P2, the main research area is cyclohexadiene scaffold enantioselective preparation; diyne Morita Baylis Hillman adduct enantioselective cycloaddition rhodium catalyst.

A rhodium-catalyzed asym. synthesis of 5,5-disubstituted cyclohexa-1,3-dienes has been achieved by [2+2+2] cycloaddition reactions between diynes and Morita-Baylis-Hillman (M-B-H) adducts as unsaturated substrates. Products containing two adjacent chiral centers (quaternary and tertiary, resp.) were obtained with complete diastereoselectivity and high enantioselectivity (84-97%) through a kinetic resolution of the M-B-H adduct. Furthermore, these highly substituted cyclohexadienes reacted with dienophiles to afford the corresponding Diels-Alder cycloadducts in good yields.

Advanced Synthesis & Catalysis published new progress about Alkadiynes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, COA of Formula: 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

Nishida, Goushi; Noguchi, Keiichi; Hirano, Masao; Tanaka, Ken published the artcile< Enantioselective synthesis of P-stereogenic alkynylphosphine oxides by Rh-catalyzed [2+2+2] cycloaddition>, Category: chiral-phosphine-ligands, the main research area is alkynyl phosphine oxide preparation stereoselective structure; cycloaddition dialkynyl phosphine oxide diyne rhodium binap complex catalyst; crystal mol structure stereogenic phosphorus alkynyl phosphine oxide preparation.

An enantioselective synthesis of P-stereogenic alkynylphosphine oxides through a cationic rhodium(l)/modified-binap complex catalyzed [2+2+2] cycloaddition of sym. dialkynylphosphine oxides with 1,6-diynes was developed (binap = 2,2′-bis(diphenylphosphinyl)-1,1′-binaphthyl, Z = CH2, O, or N-sulfonamide). Furthermore, this method permits the synthesis of a C2-sym. P-stereogenic bis(alkynylphosphine oxide). A crystal structure of one product was determined along with the absolute configuration of the phosphorus center.

Angewandte Chemie, International Edition published new progress about Alkadiynes Role: RCT (Reactant), RACT (Reactant or Reagent) (1,6-diynes). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, 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

Oonishi, Yoshihiro; Masusaki, Shuichi; Sakamoto, Shunki; Sato, Yoshihiro published the artcile< Rhodium(I)-Catalyzed Enantioselective Cyclization of Enynes by Intramolecular Cleavage of the Rh-C Bond by a Tethered Hydroxy Group>, Recommanded Product: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is acyl heterocyclic compound enantioselective preparation; enynol preparation enantioselective cyclization rhodium catalyst; cyclization; enantioselectivity; enyne; rhodium; σ-bond metathesis.

Rhodium(I)-catalyzed enantioselective intramol. cyclization of enynes having a hydroxy group in the tether was investigated, and various cyclic compounds possessing a chiral quaternary carbon center were obtained in high yields with high ees. In this cyclization, a Rh-C(sp2) bond in the rhodacyclopentene intermediate, which was formed by enantioselective oxidative cycloaddition of enynes to a chiral rhodium(I) complex, was intramolecularly cleaved by σ-bond metathesis of a tethered O-H bond in the substrate. Furthermore, it was found that the cyclic compounds were obtained with high ees even when the starting materials having a racemic secondary alc. moiety were used in this reaction.

Angewandte Chemie, International Editionpublished new progress about Alcohols, unsaturated Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Recommanded Product: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

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

Oonishi, Yoshihiro; Hato, Yoshio; Sato, Yoshihiro published the artcile< Rhodium(I)-Catalyzed Diastereoselective Cycloisomerization of Enynes with Tethered (S)-2-Methyl-2-propanesulfinyl Imine>, Synthetic Route of 139139-93-8, the main research area is enyne tethered sulfinyl imine rhodium catalyst cycloisomerization; cyclic diene enantioselective diastereoselective preparation dienophile Diels Alder reaction; spiroamide diastereoselective enantioselective preparation.

The rhodium(I)-catalyzed cycloisomerization of enynes with tethered (S)-2-methyl-2-propanesulfinyl imine afforded 5- or 6-membered cyclic compounds containing exocyclic 1,3-diene moieties in a stereoselective manner. The reaction proceeded through β-hydride elimination of a 7-membered azarhodacycle intermediate, which was generated from three unsaturated bonds (i.e., alkene, alkyne, and C-N bonds) and an Rh(I) complex. The resultant cyclic compounds could be reacted with various dienophiles to afford spiroamides as single isomers through the Diels-Alder reaction.

Advanced Synthesis & Catalysispublished new progress about Alkenynes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 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

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

Masutomi, Koji; Sakiyama, Norifumi; Noguchi, Keiichi; Tanaka, Ken published the artcile< Rhodium-Catalyzed Regio-, Diastereo-, and Enantioselective [2+2+2] Cycloaddition of 1,6-Enynes with Acrylamides>, Synthetic Route of 139139-86-9, the main research area is enyne enantioselective diastereoselective regioselective cycloaddition acrylamide rhodium BINAP catalyst; isoindole indene isobenzofuran amide hexahydro enantioselective diastereoselective synthesis.

A variety of partially hydrogenated isoindoles I [X = NTs; R1 = H, Me, Ph; R2 = H, Me, Et, Ph; R3 = R4 = Me, n-Bu, Ph; R3 = Me, R4 = MeO, Ph; R3R4 = (CH2)4] and their carbocyclic I [X = (MeO2C)2C; R1 = R2 = R3 = Me; R4 = Ph] and oxacyclic analogs I (X = O; R1 = n-pentyl; R2 = R3 = Me; R4 = Ph) was synthesized by rhodium(I)/(R)-H8-BINAP-catalyzed asym. [2 + 2 + 2] cycloaddition of 1,6-enynes II with acrylamides H2C:CHC(O)NR3R4. In this catalysis, regioselective insertion of acrylamide into a rhodacyclopentene intermediate and the coordination of the carbonyl group of acrylamide to the cationic rhodium center suppress the undesired β-hydride elimination.

Angewandte Chemie, International Editionpublished new progress about Alkenynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Synthetic Route of 139139-86-9.

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.; Brennan, Megan K. published the artcile< Palladium-Catalyzed Regio- and Enantioselective Allylic Alkylation of Bis Allylic Carbonates Derived from Morita-Baylis-Hillman Adducts>, Formula: C54H42N2O2P2, the main research area is Morita Baylis Hillman adduct regioselective enantioselective allylic alkylation; palladium phosphinonaphthoylaminocyclohexane catalysis regioselective enantioselective allylic alkylation; allylic carbonate regioselective enantioselective allylic alkylation palladium catalysis.

Morita-Baylis-Hillman diene adducts (e.g. (4E)-3-[(ethoxycarbonyl)oxy]-2-methylenehex-4-enoic acid Me ester) were used as substrates in the Pd-catalyzed asym. allylic alkylation reaction with O and C nucleophiles (e.g. p-methoxyphenol) in good regio- and enantioselectivity, e.g. 78 % (88 %ee) (3S,4E)-(+)-3-(4-methoxyphenoxy)-2-methylenehex-4-enoic acid Me ester (>20:1 regioisomers), using Pd2(dba)3, (1S,2S)-1,2-bis[[[2-(diphenylphosphino)naphthalen-1-yl]carbonyl]amino]cyclohexane and tetrabutylammonium triphenyldifluorosilicate as catalyst system in DME at 25°.

Organic Letterspublished new progress about Allylic alkylation catalysts, stereoselective (regioselective). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Formula: 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

Shintani, Ryo; Duan, Wei-Liang; Hayashi, Tamio published the artcile< Rhodium-Catalyzed Asymmetric Construction of Quaternary Carbon Stereocenters: Ligand-Dependent Regiocontrol in the 1,4-Addition to Substituted Maleimides>, Electric Literature of 139139-86-9, the main research area is rhodium complex asym addition reaction regioselectivity enantioselectivity; arylboronic acid maleimide asym addition reaction.

A rhodium-catalyzed asym. 1,4-addition of arylboronic acids of formula ArB(OH)2 (Ar = Ph, 2-naphthyl, 2-methylphenyl, 4-methoxyphenyl, 4-fluorophenyl) to substituted maleimides (I; R = Et, Me, i-Pr) has been described. The regioselectivity in this reaction is controlled by the choice of ligand (dienes or bisphosphines), and 1,4-adducts with a quaternary stereocenter (II; Ar, R = same as above) can be obtained with high regio- and enantioselectivity over 1,4-adducts with a secondary carbon center (III; Ar, R = same as above) by the use of (R)-H8-BINAP (IV). For example, I (R = Et), 3.0 equiv phenylboronic acid, 2.5 mol% divinylrhodium chloride dimer, IV (Rh/ligand = 1:1), and 0.5 equiv KOH were stirred in a 10:1 mixture of dioxane and water at 50° for 3 h to give a 87:13 mixture of II (Ar = Ph, R = Et) and III (Ar = Ph, R = Et) in 98% yield.

Journal of the American Chemical Societypublished new progress about Boronic acids Role: RCT (Reactant), RACT (Reactant or Reagent) (arylboronic acids). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Electric Literature of 139139-86-9.

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