Month: December 2022

CpCo(I) precatalysts for [2 + 2 + 2] cycloaddition reactions: synthesis and reactivity was written by Fischer, Fabian;Pientka, Tobias;Jiao, Haijun;Spannenberg, Anke;Hapke, Marko. And the article was included in Catalysis Science & Technology in 2020.HPLC of Formula: 252288-04-3 This article mentions the following:

The efficient synthesis and structural characterization of a series of novel CpCo(I)-olefin-phosphite/phosphoramidite complexes and their evaluation in catalytic cyclotrimerization reactions are reported. The protocol for precatalyst synthesis is widely applicable to different P-containing ligands, especially phosphites and phosphoramidites, as well as acyclic and cyclic olefins. A selection of the prepared complexes was investigated towards their catalytic performance in [2 + 2 + 2] cycloaddition reactions of diynes and nitriles, as well as triynes. While revealing significant differences in reactivity, the most reactive precatalysts work even already at 75°. One of these precatalysts also proved its potential in exemplary (co)cyclotrimerizations towards functionalized pyridines and benzenes. The energetics of complex formation and exemplary ligand exchange with a substrate diyne were elucidated by theor. calculations and compared with the catalytic reactivity. In the experiment, the researchers used many compounds, for example, (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3HPLC of Formula: 252288-04-3).

(11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3) belongs to chiral phosphine ligands. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.HPLC of Formula: 252288-04-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric C-H functionalization of indoles via enantioselective protonation was written by Qiu, Huang;Zhang, Dan;Liu, Shunying;Qiu, Lin;Zhou, Jun;Qian, Yu;Zhai, Changwei;Hu, Wenhao. And the article was included in Huaxue Xuebao in 2012.Electric Literature of C48H29O4P This article mentions the following:

Asym. C-H functionalization of indoles from Rh₂(OAc)₄ and chiral phosphoric acid co-catalyzed reactions of aryl diazoacetates with indoles has been investigated. Through mechanistic study regarding to the proton transfer pathway of the C-H functionalization of indoles, a new strategy to achieve the asym. C-H functionalization of indoles from metal carbenoids via enantioselective protonation has been proposed. We initially carried out a deuterium isotope experiments in order to obtain more insight into the proton transfer process of the C-H functionalization of indoles, and the experiments indicated an indirect proton transfer in the reaction. A proton-transfer shuttle such as H₂O was needed to complete the reaction. The observation provides us an opportunity to design a chiral proton-transfer shuttle to achieve the asym. C-H functionalization. In this paper, Rh₂(OAc)₄ catalyzed diazo decomposition of a aryl diazoacetate generates a metal carbenoid. Reaction of the metal carbenoid with an indole at C-3 position generates a zwitterionic intermediate. A bifunctional chiral phosphoric acid serves as a chiral proton shuttle and helps the proton transfer process via an enantioselective protonation to finish the reaction in high yield and enantioselectivity. A number of indoles including N-alkyl, aryl, silyl and a number of a-aryl-a-diazoesters are well tolerated under the established catalytic conditions, providing good to high enantioselectivity (up to 94% ee) in excellent yield (up to 99% yield). A representative procedure for the enantioselective C-H functionalization of indoles is as following: A mixture of 6-chloro-N-methylindole (1e) (41 mg, 0.25 mmol), transition metal catalyst Rh₂(OAc)₄ (1 mg, 0.0025 mmol, 1 mol%), chiral phosphoric acid co-catalyst (R)-4j (3.8 mg, 0.005 mmol, 2 mol%) and 4 Å MS (100 mg) in 1 mL of toluene was stirred at the 0°C. Me phenyl(diazo)acetate (2a) (53 mg, 0.3 mmol) in 1 Ml of toluene was added over 1 h period of time via a syringe pump. After completion of the addition, the reaction was stirred for addnl. 5 min at the same temperature Solvent was evaporated under reduced pressure to give corresponding crude product, I. The crude product was purified by flask chromatog. on silica gel (eluent: EtOAc/light petroleum ether, V : V = 1 : 40 ∼ 1 : 10) to give the pure product 3q in 92% yield with 94% ee. In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3Electric Literature of C48H29O4P).

(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Electric Literature of C48H29O4P

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Bronsted acid-catalyzed efficient Strecker reaction of ketones, amines and trimethylsilyl cyanide was written by Zhang, Guang-Wu;Zheng, Dong-Hua;Nie, Jing;Wang, Teng;Ma, Jun-An. And the article was included in Organic & Biomolecular Chemistry in 2010.Safety of (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide This article mentions the following:

A general method for the one-pot, three-component Strecker reaction of ketones was developed using Bronsted acids as organocatalysts. A series of α-aminonitriles were obtained in good to excellent yields (79-99%). A preliminary extension to a catalytic enantioselective three-component Strecker reaction of ketones (up to 40% ee) is also described. In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3Safety of (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide).

(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) 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 (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective Dearomative Arylation of Isoquinolines was written by Zhang, Ming;Sun, Wangsheng;Zhu, Gongming;Bao, Guangjun;Zhang, Bangzhi;Hong, Liang;Li, Min;Wang, Rui. And the article was included in ACS Catalysis in 2016.Reference of 1043567-32-3 This article mentions the following:

The C1-substituted tetrahydroisoquinolines and 1,2-dihydroisoquinoline constitute an important group and are interesting structural motifs found in many natural products and pharmaceuticals. In this context, a phosphoric acid-catalyzed enantioselective dearomative arylation of isoquinolines was realized, providing the chiral dihydroisoquinolines with indole substituents at the C1-position in good results (up to >99% yield and 97% ee). The reaction features mild reaction conditions and operational simplicity, which make it an attractive approach to the discovery of biol. interesting α-indolisoquinolines. In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3Reference of 1043567-32-3).

(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) 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. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Reference of 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Convergent Asymmetric Disproportionation Reactions: Metal/Bronsted Acid Relay Catalysis for Enantioselective Reduction of Quinoxalines was written by Chen, Qing-An;Wang, Duo-Sheng;Zhou, Yong-Gui;Duan, Ying;Fan, Hong-Jun;Yang, Yan;Zhang, Zhang. And the article was included in Journal of the American Chemical Society in 2011.Recommanded Product: 1043567-32-3 This article mentions the following:

A convergent asym. disproportionation of dihydroquinoxalines for the synthesis of chiral tetrahydroquinoxalines using a metal/Bronsted acid relay catalysis system has been developed. The use of hydrogen gas as the reductant makes the convergent disproportionation an ideal atom-economical process. A dramatic reversal of enantioselectivity was observed in the reduction of quinoxalines because of the different steric demands in the 1,2- and 1,4-hydride transfer pathways. In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3Recommanded Product: 1043567-32-3).

(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Recommanded Product: 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric Synthesis of Planar Chiral Ferrocenes by Enantioselective Intramolecular C-H Arylation of N-(2-Haloaryl)ferrocenecarboxamides was written by Liu, Lantao;Zhang, An-An;Zhao, Rui-Juan;Li, Feng;Meng, Tuan-Jie;Ishida, Naoki;Murakami, Masahiro;Zhao, Wen-Xian. And the article was included in Organic Letters in 2014.HPLC of Formula: 252288-04-3 This article mentions the following:

The palladium-catalyzed intramol. C-H arylation reaction of N-(2-bromoaryl)ferrocenecarboxamides furnishes planar chiral ferrocene derivatives TADDOL-derived phosphoramide ligands induce enantioselectivities ranging from 91:9 to 98:2 er. In the experiment, the researchers used many compounds, for example, (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3HPLC of Formula: 252288-04-3).

(11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.HPLC of Formula: 252288-04-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Chiral Phosphoric Acid Catalyzed Intramolecular Dearomative Michael Addition of Indoles to Enones was written by Zhou, Yong;Xia, Zi-Lei;Gu, Qing;You, Shu-Li. And the article was included in Organic Letters in 2017.HPLC of Formula: 1043567-32-3 This article mentions the following:

An enantioselective intramol. dearomative Michael addition of indolyl enones is presented. In the presence of catalytic amount of chiral phosphoric acid, various enantioenriched spiro-indolenines bearing a quaternary stereogenic center were obtained with good yields and enantioselectivity (up to 97% ee) under mild reaction conditions. In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3HPLC of Formula: 1043567-32-3).

(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.HPLC of Formula: 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Towards a Zinc-Catalyzed Asymmetric Hydrogenation/Transfer Hydrogenation of Imines was written by Werkmeister, Svenja;Fleischer, Steffen;Junge, Kathrin;Beller, Matthias. And the article was included in Chemistry – An Asian Journal in 2012.Related Products of 252288-04-3 This article mentions the following:

The first asym. hydrogenation/transfer hydrogenation of imines to amines using zinc(II) triflate in combination with chiral ligands is described. The monodentate binaphthophosphepine ligand provided the highest enantioselectivities. Using different imines, the corresponding amines were obtained in moderate yields and enantioselectivities. In the experiment, the researchers used many compounds, for example, (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3Related Products of 252288-04-3).

(11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine (cas: 252288-04-3) 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.Related Products of 252288-04-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Organocatalytic Aza-Friedel-Crafts/Lactonization Domino Reaction of Naphthols and Phenols with 2-Acetamidoacrylate to Naphtho- and Benzofuranones Bearing a Quaternary Center at the C3 Position was written by Bartoccini, Francesca;Mari, Michele;Retini, Michele;Bartolucci, Silvia;Piersanti, Giovanni. And the article was included in Journal of Organic Chemistry in 2018.Product Details of 1043567-32-3 This article mentions the following:

N-Acetyl ketimine generated from Me 2-acetamidoacrylate was explored to develop an unprecedented domino aza-Friedel-Crafts/lactonization reaction with naphthols and phenols (including 5-hydroxyindoles). This novel method requires a catalyst loading of only 5 mol % of a phosphoric acid catalyst and provides a new series of 3-NHAc-naphtho- and benzofuranone derivatives bearing tetra-substituted stereogenic centers in moderate-to-good yields. The enantioselective variant using BINOL-derived phosphoric acids was also explored with 1-naphthol, providing the desired product with moderate enantioselectivities (up to 99:1 following recrystallization). In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3Product Details of 1043567-32-3).

(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) 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.Product Details of 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic Asymmetric Synthesis of 3,3′-Bisindoles Bearing Single Axial Chirality was written by Chen, Ke-Wei;Wang, Zhao-Shan;Wu, Ping;Yan, Xin-Yu;Zhang, Shu;Zhang, Yu-Chen;Shi, Feng. And the article was included in Journal of Organic Chemistry in 2020.COA of Formula: C48H29O4P This article mentions the following:

A catalytic asym. synthesis of 3,3′-bisindoles bearing single axial chirality has been established via chiral phosphoric acid (CPA)-catalyzed enantioselective addition reaction of 3,3′-bisindoles with ninhydrin-derived 3-indolylmethanols. The selection of ninhydrin-derived 3-indolylmethanols as suitable electrophiles is based on the consideration that the sym. and bulky moiety of ninhydrin would increase the steric congestion around the axis to generate stable axial chirality and avoid the generation of central chirality. By this approach, a series of 3,3′-bisindoles bearing single axial chirality were synthesized via the dynamic kinetic resolution (DKR) process in generally acceptable yields and considerable enantioselectivities. In addition, an in-depth investigation on the property (stability and rotation barrier) of the synthesized axially chiral 3,3′-bisindoles was carried out, thus providing useful information on this class of axially chiral frameworks. This approach makes use of the strategy of dynamic kinetic resolution of 3,3′-bisindoles, therefore expanding the generality and applicability of this strategy for catalytic asym. synthesis of 3,3′-bisindoles bearing single axial chirality. In the experiment, the researchers used many compounds, for example, (11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3COA of Formula: C48H29O4P).

(11bS)-4-Hydroxy-2,6-di(phenanthren-9-yl)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepine 4-oxide (cas: 1043567-32-3) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.COA of Formula: C48H29O4P

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis