Tag: 440.496

Stereoselective Process for a CCR3 Antagonist was written by Yue, Tai-Yuen;McLeod, Douglas D.;Albertson, Kevin B.;Beck, Steven R.;Deerberg, Joerg;Fortunak, Joseph M.;Nugent, William A.;Radesca, Lilian A.;Tang, Liya;Xiang, Cathie Dong. And the article was included in Organic Process Research & Development in 2006.Application of 77876-39-2 This article mentions the following:

A convergent, multikilogram, stereoselective synthesis of 1 is described. A key fragment, (S)-3-(4-fluorobenzyl)piperidine (2) was synthesized from valerolactam in three steps using our recently discovered Ir-BDPP-catalyzed asym. hydrogenation. Another key fragment, (1R,2R)-2-(benzyloxycarbonylamino)cyclohexanecarboxaldehyde (3) was synthesized from meso-hexahydrophthalic anhydride in seven steps. The stereochem. was set in the first step of this sequence via a quinidine-mediated desymmetrization of the meso-anhydride. Coupling of the fragments 2 and 3 followed by deprotection provided the penultimate 23. The active pharmaceutical ingredient (API) free base 1 was obtained by treatment of 23 with the aminothiazole fragment 4 under mild conditions. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Application of 77876-39-2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Application of 77876-39-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Copper-Catalyzed Regio- and Stereoselective Aminoboration of Alkenylboronates was written by Nishikawa, Daiki;Hirano, Koji;Miura, Masahiro. And the article was included in Organic Letters in 2016.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) This article mentions the following:

A Cu-catalyzed aminoboration of alkenyl dan boronates (dan = 1,8-diaminonaphthyl) with diboron reagents and hydroxylamines was developed. The reaction proceeds regio- and stereoselectively to form the corresponding β-boryl-α-aminoboronic acid derivatives of potent interest in medicinal chem. Addnl., the ligand-controlled syn/anti diastereoselectivity switching and preliminary asym. catalysis are also described. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Many phosphine-catalyzed reactions have been developed for the syntheses of various biologically important acyclic and cyclic molecules. Asymmetric variants of these reactions have evolved relatively slowly. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic Enantioselective Hydrovinylation of Trialkylsilyloxy and Acetoxy-1,3-Dienes: Cationic Co(I) Complexes for the Synthesis of Chiral Enolate Surrogates and Their Applications for Synthesis of Ketones and Cross-Coupling Reagents in High Enantiomeric Purity was written by Biswas, Souvagya;Dewese, Kendra R.;Raya, Balaram;RajanBabu, T. V.. And the article was included in ACS Catalysis in 2022.Name: (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) This article mentions the following:

(E)-2-Trialkylsilyloxy-1,3-dienes and the corresponding 2-acetoxy derivatives participate in Co-catalyzed heterodimerization reactions with ethylene, giving mostly 4,1-hydrovinylation products with addition of the vinyl group to C₄ and H at C₁ of the diene. The reaction, which gives highly functionalized, protected enolates, is best carried out at room temperature with the diene dissolved in CH₂Cl₂ and ethylene delivered from a balloon in the presence of a catalyst generated in situ by the reaction of (P~P)CoCl₂ with methylaluminoxane (MAO). Com. available chiral ligands, 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis-(diphenylphosphino)butane (DIOP) and 2,4-bis-diphenylphosphinopentane (BDPP) in combination with the earth-abundant metal Co, gave excellent regio- and enantioselectivities (up to 99% ee) for the chiral enolate surrogates from both silyloxy and acetoxydienes. Hydrolyzes of the silyl enol ethers lead to β-vinyl ketones, thus providing a practical two-step approach to these valuable synthons starting from α,β-unsaturated ketones and ethylene. The hydrovinylated silyl enol ethers undergo typical nucleophilic reactions such as alkylation, aldol, and Michael and Mannich reactions with varying degrees of diastereoselectivity (2:1-13:1). The silyl enol ethers are convenient sources of Li enolates, which are readily converted into other vinyl derivatives such as vinyl acetates and vinyl triflates. The vinyl triflates are excellent partners for cross-coupling chem., giving potentially useful, polyolefinic chiral synthons for further applications. Chemoselective reduction and hydrosilylation of the vinyl group in the chiral β-vinyl silyl enol ether further illustrate other potential reactivities of these versatile synthons. Since isolated cationic [(P~P)Co(I)]⁺ [BARF]^– appears to be an excellent catalyst for the heterodimerization of silyl enol ethers and ethylene giving products very similar in yield and selectivities to what is observed in the MAO-mediated reactions, probably a previously invoked Co(I)/Co(III) cycle, common to other similar heterodimerization reactions, might be involved in these reactions as well. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Name: (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Many phosphine-catalyzed reactions have been developed for the syntheses of various biologically important acyclic and cyclic molecules. Asymmetric variants of these reactions have evolved relatively slowly. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Name: (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Chiral discrimination at the η³-allyl units of rhodium(I) η³-cyclooctenyl complexes containing chiral bidentate phosphines was written by Lange, Susanne;Wittmann, Klaus;Gabor, Barbara;Mynott, Richard;Leitner, Walter. And the article was included in Tetrahedron: Asymmetry in 1998.Recommanded Product: (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) This article mentions the following:

A three step synthesis of Rh(I) η³-cyclooctenyl complexes [(P₂^*)Rh(η³-C₈H₁₃)] (P₂^* = chiral bidentate phosphine, e.g. (S,S)-4,5-bis(diphenylphosphinomethyl)-2,2-dimethyl-1,3-dioxolane) starting from com. available [{(cod)Rh(μ-Cl)}₂] is described. Examination of these complexes by multinuclear NMR-spectroscopy reveals a distinct stereochem. differentiation of the terminal positions of the η³-allyl unit. Preliminary results on the reactivity of these compounds towards various electrophiles E-X (e.g. MeOTf) are reported; hydrogen transfer is preferred over formation of C-E bonds. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Recommanded Product: (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Recommanded Product: (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Synthesis of β-Boryl-α-Aminosilanes by Copper-Catalyzed Aminoboration of Vinylsilanes was written by Kato, Kodai;Hirano, Koji;Miura, Masahiro. And the article was included in Angewandte Chemie, International Edition in 2016.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) This article mentions the following:

A Cu-catalyzed regioselective and stereospecific aminoboration of vinylsilanes with bis(pinacolato)diboron (pinB-Bpin) and hydroxylamines was developed. In the presence of a CuCl/MeO-dppbz catalyst, the boryl group and amino group are incorporated at the β position and α position, resp., and the corresponding β-boryl-α-aminosilanes were obtained with good diastereoselectivity. The boryl group is a good latent functional group, and subsequent manipulations provide a variety of β-functionalized α-aminosilanes of great potential in medicinal chem. Addnl., preliminary application to asym. catalysis is also described. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. During the past two decades, tertiary phosphine catalysts have been applied extensively in a wide range of carbon–carbon and carbon–heteroatom bond-forming transformations. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Sequence of Intramolecular Carbonylation and Asymmetric Hydrogenation Reactions: Highly Regio- and Enantioselective Synthesis of Medium Ring Tricyclic Lactams was written by Lu, Shui-Ming;Alper, Howard. And the article was included in Journal of the American Chemical Society in 2008.Category: chiral-phosphine-ligands This article mentions the following:

The intramol. cyclocarbonylation reaction of (aminoaryloxy)-functionalized arylalkynes and analogs I (X = N, CH, CCl; Y = O, NMe, OCH₂, OCH₂CH₂; R¹ = H, Me, OMe, CN, CF₃, Cl, MeCO; R² = H, Me, CO₂Me; R³ = H, Cl, Me, CO₂Me) with palladium-complexed dendrimers on silica is a very effective method for the regioselective synthesis of methylene 8-, 9-, and 10-membered rings II. The heterogeneous dendritic catalysts were easily recovered by simple filtration and reused for up to 10 cycles with only a slight loss of activity. Asym. hydrogenation of the resulting unsaturated heterocycles II afforded optically active tricyclic lactams III in excellent yields and in high enantiomeric excess. This process can tolerate a wide array of functional groups, including halide, ether, nitrile, ketone, and ester. Moreover, the variation of heteroatom on the rings does not have any influence on the efficiency and enantioselectivity of the reaction. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Category: chiral-phosphine-ligands).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. During the past two decades, tertiary phosphine catalysts have been applied extensively in a wide range of carbon–carbon and carbon–heteroatom bond-forming transformations. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Histidine and deuterium labeled histidine by asymmetric catalytic reduction with gaseous H₂ or D₂; the role of strong non-coordinating acids was written by Cesarotti, E.;Rimoldi, I.;Zerla, D.;Aldini, G.. And the article was included in Tetrahedron: Asymmetry in 2008.Product Details of 77876-39-2 This article mentions the following:

An efficient and convenient route for the preparation of natural and unnatural histidine by asym. hydrogenation with rhodium-phosphine complexes is described. The reductions were performed in the presence of HBF₄ to generate an essential imidazolyl cation. Stereoselective incorporation of D₂ in the α,β-positions was obtained by catalytic deuteration in the presence of MeOD. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Product Details of 77876-39-2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Phosphine-catalyzed asymmetric reactions are now powerful and versatile tools for the construction of C–C, C–N, C–O, and C–S bonds and for the syntheses of functionalized carbocycles and heterocycles. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Product Details of 77876-39-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Chiral paramagnetic closo-ruthenacarboranes via phosphine-diphosphine displacement reaction of “three-bridge” exo-nido-ruthenacarboranes: Molecular Structure of (-)-[closo-3-Cl-3,3-{(Ph₂PCHCH₃)₂CH₂}-3,1,2-RuC₂B₉H₁₁] and its ortho-cycloboronated derivative was written by Cheredilin, Dmitri N.;Kadyrov, Renat;Dolgushin, Fedor M.;Balagurova, Elena V.;Godovikov, Ivan A.;Solodovnikov, Stanislav P.;Chizhevsky, Igor T.. And the article was included in Inorganic Chemistry Communications in 2005.SDS of cas: 77876-39-2 This article mentions the following:

Ruthenacarboranes with chiral non-racemic (2S,4S)-2,4-bis(diphenylphosphino)pentane ligand were prepared by ligand substitution and cage closing of ruthenium nido-carborane complexes. Treatment of [exo-nido-[Cl(Ph₃P)₂Ru]-(μ-H)₃-10-H-7,8-C₂B₉H₈] (1) with the (2S,4S)-(-)-2,4-bis(diphenylphosphino)pentane (3, BDPP) in toluene results in the formation of three novel optically active diphosphine-ruthenium closo complexes, 18e diamagnetic (-)-[closo-3-Cl-3,3-[(S,S)-BDPP]-3-H-3,1,2-RuC₂B₉H₁₁] (4), and 17e paramagnetic (-)-[closo-3-Cl-3,3-[(S,S)-BDPP]-3,1,2-RuC₂B₉H₁₁] (5) along with its ortho-cycloboronated derivative (-)-[closo-3-Cl-3,3-[(S,S)-Ph₂PCH(CH₃)CH₂CH(CH₃)PPh-ortho-C₆H₄]-3,1,2-RuC₂B₉H₁₀] (6). Both odd-electron complexes 5 and 6 were characterized by single-crystal x-ray diffraction anal. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2SDS of cas: 77876-39-2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.SDS of cas: 77876-39-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Regio- and Stereoselective Synthesis of Key 1-Methyl Carbapenem Intermediates via Hydroformylation Using a Zwitterionic Rhodium Catalyst was written by Park, H. S.;Alberico, E.;Alper, H.. And the article was included in Journal of the American Chemical Society in 1999.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) This article mentions the following:

The asym. hydroformylation of a 4-vinyl β-lactam catalyzed by a rhodium catalyst with a chiral phosphine ligand was investigated. The catalytic system consisting of a zwitterionic rhodium catalyst, (NBD)Rh⁺(C₆H₅B^–Ph₃), and (S,S)-2,4 bis(diphenylphosphino)pentane, (S,S)-BDPP, gave branched aldehydes in high regio- and stereoselectivity. The hydroformylated products are key intermediates in the synthesis of 1-methylcarbapenem antibiotics. Using (3S,4R)-3-[(R)-1-(tert-butyldimethyl-silyloxy)ethyl]-4-vinyl-2-azetidinone as the reactant afforded aldehydes in a 97:3 branched-to-linear ratio and 91:9 to β- to α-branched isomers. The regio (branched/linear)- and stereoselectivity (β/α) was >99:1 when (3S,4R)-1-N-BOC-3-[(R)-1-methoxyethyl]-4-vinyl-2-azetidinone was used as the substrate. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric Synthesis of C₂-Symmetric Axially Chiral Biaryls through Rhodium-Catalyzed and Alkyne-Controlled Diastereoselective Double [2+2+2]Cycloaddition was written by Mori, Ayaka;Araki, Tatsuya;Miyauchi, Yuta;Noguchi, Keiichi;Tanaka, Ken. And the article was included in European Journal of Organic Chemistry in 2013.Computed Properties of C29H30P2 This article mentions the following:

The asym. synthesis of C₂-sym. axially chiral biaryls was achieved by the cationic rhodium(I)/1,3-bis(diphenylphosphino)propane (dppp) complex catalyzed diastereoselective double [2+2+2]cycloaddition of (R)-3-butyn-2-ol-derived tetraynes with functionalized monoynes. Interestingly, the use of propiolate derivatives afforded biaryls possessing large dihedral angles, and in contrast, the use of propargyl alc. afforded biaryls possessing small dihedral angles. The title compounds thus formed included an isobenzofuran dimer (I) and related substances. Under optimized reaction conditions, the synthesis of the target compounds was achieved using bis(norbornadiene)rhodium(I) tetrafluoroborate and 1,1′-(1,3-propanediyl)bis[1,1-diphenylphosphine] as catalyst combination. The synthesis of the target compounds was achieved by a reaction of chiral 1,6-bis(2-butyn-1-yloxy)-2,4-hexadiyne, 1,6-bis(2-propyn-1-yloxy)-2,4-hexadiyne, 1,1′-[(2,4-hexadiyne-1,6-diyl)bis(oxy-1-propyne-3,1-diyl)]bis[benzene] with alkyne derivatives In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Computed Properties of C29H30P2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Many phosphine-catalyzed reactions have been developed for the syntheses of various biologically important acyclic and cyclic molecules. Asymmetric variants of these reactions have evolved relatively slowly. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Computed Properties of C29H30P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis