Month: February 2023

Stereodivergent Synthesis of Tertiary Fluoride-Tethered Allenes via Copper and Palladium Dual Catalysis was written by Yang, Shao-Qian;Wang, Yi-Fan;Zhao, Wei-Cheng;Lin, Guo-Qiang;He, Zhi-Tao. And the article was included in Journal of the American Chemical Society in 2021.Recommanded Product: 352655-61-9 This article mentions the following:

Herein we describe a protocol for the unprecedented stereodivergent synthesis of tertiary fluoride-tethered allenes bearing a stereogenic center and stereogenic axis via Cu/Pd synergistic catalysis. A broad scope of conjugated enynes are coupled with various α-fluoroesters in high yields with high diastereoselectivities and generally >99% ee. In addition, the four stereoisomers of the allene products ensure precise access to the corresponding four stereoisomers of the fluorinated hydrofurans via a novel stereodivergent axial-to-central chirality transfer process. In the experiment, the researchers used many compounds, for example, (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl (cas: 352655-61-9Recommanded Product: 352655-61-9).

(R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl (cas: 352655-61-9) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Recommanded Product: 352655-61-9

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium/PC-Phos-Catalyzed Enantioselective Arylation of General Sulfenate Anions: Scope and Synthetic Applications was written by Wang, Lei;Chen, Mingjie;Zhang, Peichao;Li, Wenbo;Zhang, Junliang. And the article was included in Journal of the American Chemical Society in 2018.Reference of 2162939-89-9 This article mentions the following:

Herein we reported an efficient palladium-catalyzed enantioselective arylation of both alkyl and aryl sulfenate anions to deliver various chiral sulfoxides I [R¹ = Bn, CH₃(CH₂)₁₁, Me, i-Pr, cyclopentyl, etc.; R² = H, 4-Me, 4-OMe, 3-CO₂Me, 3-Cl, etc.] in good yields (up to 98%) with excellent enantioselectivities (up to 99% ee) by the use of our developed chiral O,P-ligands (PC-Phos). PC-Phos are easily prepared in short steps from inexpensive com. available starting materials. The single-crystal structure of the PC4/PdCl₂ showed that a rarely observed 11-membered ring was formed via the O,P-coordination with the palladium(II) center. The salient features of this method include general substrate scope, ease of scale-up, applicable to the late-stage modification of bioactive compounds, and the synthesis of a marketed medicine Sulindac. In the experiment, the researchers used many compounds, for example, (R)-N-((S)-1-(5-(Diphenylphosphanyl) -9,9-dimethyl-9H-xanthen-4-yl)-2,2-dimethylpropyl)-2-methylpropane-2-sulfinamide (cas: 2162939-89-9Reference of 2162939-89-9).

(R)-N-((S)-1-(5-(Diphenylphosphanyl) -9,9-dimethyl-9H-xanthen-4-yl)-2,2-dimethylpropyl)-2-methylpropane-2-sulfinamide (cas: 2162939-89-9) 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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Reference of 2162939-89-9

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic Asymmetric Synthesis of Quaternary Carbons Bearing Two Aryl Substituents. Enantioselective Synthesis of 3-Alkyl-3-Aryl Oxindoles by Catalytic Asymmetric Intramolecular Heck Reactions was written by Dounay, Amy B.;Hatanaka, Keiko;Kodanko, Jeremy J.;Oestreich, Martin;Overman, Larry E.;Pfeifer, Lance A.;Weiss, Matthew M.. And the article was included in Journal of the American Chemical Society in 2003.Reference of 77876-39-2 This article mentions the following:

A practical sequence involving three consecutive palladium(0)-catalyzed reactions has been developed for synthesizing 3-alkyl-3-aryloxindoles in high enantiopurity. Butenanilide I (R = Bu₃Sn) is prepared in two steps by lithiation of propargyl Me ether, addition of the acetylide to 3-benzyl-2-benzooxazolidinone, and triflation of the free phenoxide followed by palladium-catalyzed regioselective addition of tributyltin hydride to the alkyne. I (R = Ph, 4-MeOC₆H₄, 3-pyridyl, 4-AcNHC₆H₄, 1-naphthyl, 2-O₂NC₆H₄, 3-Me-2-O₂NC₆H₃, 1-benzyl-7-indolinyl, 1-benzyl-3-indolyl, 2-BocNHC₆H₄, 2-BnNHC₆H₄, 1-benzyl-3,3-dimethyl-2-oxo-7-indolinyl) are prepared by chemo- and stereoselective Stille cross-coupling of butenanilide I (R = Bu₃Sn) with aryl or heteroaryl iodides in the presence of Pd₂(dba)₃^.CHCl₃, tri(2-furyl)phosphine, and copper (I) iodide. Catalytic asym. Heck cyclization of I (R = Ph, 4-MeOC₆H₄, 3-pyridyl, 4-AcNHC₆H₄, 1-naphthyl, 2-O₂NC₆H₄, 3-Me-2-O₂NC₆H₃, 1-benzyl-7-indolinyl, 1-benzyl-3-indolyl, 2-BocNHC₆H₄, 2-BnNHC₆H₄, 1-benzyl-3,3-dimethyl-2-oxo-7-indolinyl) in the presence of palladium (II) acetate and either (R)-BINAP or (R)-p-tol-BINAP yields arylindolines such as II containing diaryl-substituted all-carbon quaternary carbon centers in 14-95% yields and in 71-98% ee. Indolinones possessing a wide variety of aryl and heteroaryl substituents, including ones of considerable steric bulk, are prepared by this method. Heck cyclization of precursors with aryl substituents containing ortho nitro or basic amine functionalities or the bulky N-alkyl-7-oxindolyl group is sluggish or does not occur. Heck cyclizations with dimethyloxindolyl-substituted Heck precursors give both oxindoles and quinolinones; for the 1,3,3-trimethyloxindolyl-substituted compound, the replacement of 1,2,2,6,6-pentamethylpiperidine with 1,8-dimethylaminonaphthalene (Proton Sponge) increases the regioselectivity of Heck cyclization for the desired oxindole over quinolone byproducts while the corresponding 1-benzyl-3,3-dimethyloxindolyl-substituted compound undergoes cyclization mainly to quinolinone byproducts under the same conditions. Heck cyclization of a butenanilide containing an N-acetyl-N-benzylaminophenyl group yields stereoisomers derived from hindered rotation of the aryl-nitrogen bond; the atropisomers are formed directly from substrate as they interconvert very slowly under the reaction conditions. The rotational barrier between the atropisomers is determined by variable temperature NMR methods. Both atropisomers possess the same absolute stereochem. at their quaternary carbon centers. The asym. Heck reaction has potential use in the preparation of polycyclic indole alkaloids such as psycholeine and quadrigemine C. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Reference of 77876-39-2).

(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. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Reference of 77876-39-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Solid-phase synthesis of recyclable diphosphine ligands was written by Heutz, Frank J. L.;Samuels, Michiel C.;Kamer, Paul C. J.. And the article was included in Catalysis Science & Technology in 2015.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) This article mentions the following:

An efficient solid-phase synthetic approach towards diphosphine ligands is demonstrated. This modular method offers facile access to this important class of ligands, in quant. yield, providing huge potential for ligand fine-tuning. These supported ligands can be efficiently applied in asym. catalysis. Moreover, the immobilized catalysts can successfully be recycled multiple times addressing several synthetic and work-up challenges in the field of catalytic chem. 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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

The use of silyl ketene acetals and enol ethers in the catalytic enantioselective alkylative ring opening of oxa/aza bicyclic alkenes was written by Zhang, Lei;Le, Christine M.;Lautens, Mark. And the article was included in Angewandte Chemie, International Edition in 2014.Synthetic Route of C52H60FeN2P2 This article mentions the following:

Silyl ketene acetals and enol ethers are employed as reactive and functional group tolerant nucleophiles in the enantioselective rhodium-catalyzed alkylative ring opening of a diverse class of oxa/azabicyclic alkenes. This method provides access to enantio-enriched dihydronaphthalene and cyclohexene scaffolds, which have the potential to be derivatized toward core motifs of naphthoquinone and sesquiterpene natural products. In the experiment, the researchers used many compounds, for example, (R,R)-2,2′-Bis[(R)-(N,N-dimethylamino)(phenyl)methyl]-1,1′-bis(diphenylphosphino)ferrocene (cas: 174467-31-3Synthetic Route of C52H60FeN2P2).

(R,R)-2,2′-Bis[(R)-(N,N-dimethylamino)(phenyl)methyl]-1,1′-bis(diphenylphosphino)ferrocene (cas: 174467-31-3) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Synthetic Route of C52H60FeN2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Half-sandwich rhodium (and iridium) complexes as enantioselective catalysts for the 1,3-dipolar cycloaddition of 3,4-dihydroisoquinoline n-oxide to methacrylonitrile was written by Carmona, Daniel;Lamata, M. Pilar;Viguri, Fernando;Rodriguez, Ricardo;Lahoz, Fernando J.;Oro, Luis A.. And the article was included in Chemistry – A European Journal in 2007.Application of 37002-48-5 This article mentions the following:

Cationic half-sandwich complexes containing the [(η⁵-C₅Me₅)M-(Diphos^*)] moiety (M = Rh, Ir; Diphos^* = chiral diphosphine ligand) catalyze the cycloaddition of the nitrone 3,4-dihydroisoquinoline N-oxide (A) to methacrylonitrile (B) with excellent regio and endo selectivity and low-to-moderate enantioselectivity. The most active and selective catalyst, (S_Rh,R_C)-[(η⁵-C₅Me₅)Rh{(R)-Prophos}(NC(Me)C:CH₂)](SbF₆)₂, has been isolated and fully characterized including the determination of the mol. structure by x-ray diffraction. The R-at-metal epimers of the complexes [(η⁵-C₅Me₅)M{(R)-Prophos}(NC(Me)C:CH₂)](SbF₆)₂ (M = Rh, Ir) isomerize to the corresponding S-at-metal diastereomers. The stoichiometric cycloaddition of A with B is catalyzed by diastereopure (S_M,R_C)-[(η⁵-C₅Me₅)M{(R)-Prophos}(NC(Me)C:CH₂)](SbF₆)₂ with perfect regio and endo selectivity and very good (up to 95%) ee. The catalyst can be recycled up to nine times without significant loss of either activity or selectivity. In the experiment, the researchers used many compounds, for example, (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) (cas: 37002-48-5Application of 37002-48-5).

(((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) (cas: 37002-48-5) belongs to chiral phosphine ligands. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Application of 37002-48-5

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium-catalyzed intramolecular direct arylation for phosphorus heterocycle synthesis was written by Chen, Yun-Rong;Duan, Wei-Liang. And the article was included in Synthesis in 2014.Synthetic Route of C33H25OP This article mentions the following:

A Pd-catalyzed intramol. direct arylation of bromo-substituted phosphine oxides is reported for the synthesis of P-containing heterocycles with good to excellent yields (78-98 %). E.g., reaction of Ph₂P(O)CH₂-2-C₆H₄Br with 10 mol% Pd(OAc)₂/10 mol% PPh₃ with K₂CO₃/DMA at 60° gave a 98% yield of 5,6-dihydro-5-phenylphosphanthridine 5-oxide. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Synthetic Route of C33H25OP).

(S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Synthetic Route of C33H25OP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Regio- and Enantioselective Decarboxylative Allylic Benzylation Enabled by Dual Palladium/Photoredox Catalysis was written by Song, Changhua;Zhang, Hong-Hao;Yu, Shouyun. And the article was included in ACS Catalysis in 2022.Quality Control of (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl This article mentions the following:

A decarboxylative allylic benzylation cocatalyzed by Pd/photoredox in a regio- and enantioselective manner has been achieved. Readily available aryl acetic acids are used as benzylic nucleophile equivalent without preactivation. This mild and atom economic protocol expands the scope of coupling partners of allylic electrophiles. Vinyl epoxides could also go through this transformation smoothly, affording various chiral homoallylic alcs. bearing all-carbon quaternary stereocenters. In the experiment, the researchers used many compounds, for example, (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl (cas: 352655-61-9Quality Control of (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl).

(R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl (cas: 352655-61-9) 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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Quality Control of (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Preparation and evaluation of novel chiral stationary phases based on quinine derivatives comprising crown ether moieties was written by Wang, Dongqiang;Zhao, Jianchao;Wu, Haixia;Wu, Haibo;Cai, Jianfeng;Ke, Yanxiong;Liang, Xinmiao. And the article was included in Journal of Separation Science in 2015.Related Products of 297752-25-1 This article mentions the following:

The C9-position of quinine was modified by meta- or para-substituted benzo-18-crown-6, and immobilized on 3-mercaptopropyl-modified silica gel through the radical thiol-ene addition reaction. These two chiral stationary phases were evaluated by chiral acids, amino acids, and chiral primary amines. The crown ether moiety on the quinine anion exchanger provided a ligand-exchange site for primary amino groups, which played an important role in the retention and enantioselectivity for chiral compounds containing primary amine groups. These two stationary phases showed good selectivity for some amino acids. The complex interaction between crown ether and protonated primary amino group was studied by the addition of inorganic salts such as LiCl, NH₄Cl, NaCl, and KCl to the mobile phase. The resolution results showed that the simultaneous interactions between two function moieties (quinine and crown ether) and amino acids were important for the chiral separation In the experiment, the researchers used many compounds, for example, (R)-4-Hydroxy-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 297752-25-1Related Products of 297752-25-1).

(R)-4-Hydroxy-8,9,10,11,12,13,14,15-octahydrodinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 297752-25-1) 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.Related Products of 297752-25-1

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Nickel(0)-Catalyzed Asymmetric Ring Expansion Toward Enantioenriched Silicon-Stereogenic Benzosiloles was written by Zhang, Jinyu;Yan, Nuo;Ju, Cheng-Wei;Zhao, Dongbing. And the article was included in Angewandte Chemie, International Edition in 2021.Category: chiral-phosphine-ligands This article mentions the following:

The development of a straightforward strategy to obtain enantioenriched silicon-stereogenic benzosiloles remains a challenging yet appealing synthesis venture due to their potential future application in chiral electronic and optoelectronic devices. In this context, all of the existing methods rely on Rh-catalyzed systems and are somewhat limited in scope. Herein, we disclose the first Ni⁰-catalyzed ring expansion process that enables the preparation of benzosiloles possessing tetraorganosilicon stereocenters in excellent yields and enantioselectivities. The presented catalysis strategy is further applied to the asym. synthesis of silicon-stereogenic bis-silicon-bridged π-extended systems. Preliminary studies reveal that such compounds exhibit fluorescence emission, Cotton effects and circularly polarized luminescence (CPL) activity. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Category: chiral-phosphine-ligands).

(R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1) 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 phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis