Tag: 700-800

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

Asymmetric construction of polycyclic indoles through olefin cross-metathesis/intramolecular Friedel-Crafts alkylation under sequential catalysis was written by Cai, Quan;Zhao, Zhuo-An;You, Shu-Li. And the article was included in Angewandte Chemie, International Edition in 2009.Synthetic Route of C48H29O4P This article mentions the following:

Sequential catalytic olefin cross-metathesis of allyloxymethyl and allylaminomethyl indoles and enones followed by enantioselective Friedel-Crafts alkylation produced polycyclic indoles containing the tetrahydropyranoindole and tetrahydro-β-carboline ring systems, such as I and II, in excellent yields and excellent enantioselectivities. Chiral phosphoric acids were used as catalysts for the Friedel-Crafts alkylations of indolyl enones while both a ruthenium complex and chiral phosphoric acids were used as catalysts for sequential olefin cross-metathesis and Friedel-Crafts alkylations of allyloxymethyl or allylaminomethyl indoles and enones. 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: 1043567-32-3Synthetic Route 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. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Synthetic Route of C48H29O4P

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective synthesis of benzofurans and benzoxazines via an olefin cross-metathesis-intramolecular oxo-Michael reaction was written by Zhang, Jun-Wei;Cai, Quan;Gu, Qing;Shi, Xiao-Xin;You, Shu-Li. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2013.Recommanded Product: (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:

Chiral phosphoric acid and Hoveyda-Grubbs II were found to catalyze an olefin cross-metathesis-intramol. oxo-Michael cascade reaction of the ortho-allylphenols and enones to provide a variety of benzofuran and benzoxazine derivatives in moderate to good yields and enantioselectivity. 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: (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. 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: (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

Dual Catalysis in Highly Enantioselective Multicomponent Reaction with Water: An Efficient Approach to Chiral β-Amino-α-Hydroxy Acid Derivatives was written by Qian, Yu;Jing, Changcheng;Shi, Taoda;Ji, Jingjing;Tang, Min;Zhou, Jing;Zhai, Changwei;Hu, Wenhao. And the article was included in ChemCatChem in 2011.Computed Properties of C48H29O4P This article mentions the following:

A method for the stereoselective preparation of chiral amino hydroxy benzenepropanoate derivatives was designed and the synthesis of the target compounds was achieved in good diastereoselectivity and high enantioselectivity by an enantioselective three-component reaction of diazo compounds with imines and water in the presence of dirhodium tetraacetate [Rh₂(Ac)₄] and a chiral Bronsted acid [4-(hydroxy)dinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin 4-oxide derivatives]. This reaction represents one of a few catalytic asym. procedures using water as a reactant and provides and efficient method for the synthesis of chiral β-amino α-hydroxy acid derivatives from readily available starting materials under mild reaction conditions. The title compounds thus prepared included threo-α-hydroxy-β-[(4-methoxyphenyl)amino]-α-(phenyl)benzenepropanoic acid esters. 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: 1043567-32-3Computed Properties 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. 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.Computed Properties of C48H29O4P

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Organocatalytic Enantioselective Construction of Axially Chiral Tetrasubstituted Allenes via 1,6-Addition of Alkynyl Indole Imine Methides with 2-Substituted Indoles was written by Wu, Yu;Yue, Zhibin;Qian, Chenxiao;Chen, Xuling;Li, Fushuai;Li, Pengfei;Li, Wenjun. And the article was included in Asian Journal of Organic Chemistry in 2022.HPLC of Formula: 1043567-32-3 This article mentions the following:

An organocatalytic construction of axially chiral tetrasubstituted allenes I [R¹ = H, 5-F, 6-OMe, etc.; R² = H, F, Cl, Br; R³ = Me, t-Bu, Ph, etc.; R⁴ = Et, i-Pr, t-Bu, Bn; Ar¹ = Ph, 4-FC₆H₄, 3-FC₆H₄, 3-MeC₆H₄] featuring indole skeletons was established. With the aid of chiral phosphoric acid, alkynyl indole imine methides were formed in situ from α-(3-indolyl) propargylic alcs., followed by the asym. 1,6-conjugate addition with 2-substituted indoles, furnishing axially chiral indole-containing tetrasubstituted allenes in generally high yields and enantioselectivities. 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. 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.HPLC of Formula: 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Biomimetic Asymmetric Hydrogenation: In Situ Regenerable Hantzsch Esters for Asymmetric Hydrogenation of Benzoxazinones was written by Chen, Qing-An;Chen, Mu-Wang;Yu, Chang-Bin;Shi, Lei;Wang, Duo-Sheng;Yang, Yan;Zhou, Yong-Gui. And the article was included in Journal of the American Chemical Society in 2011.Application of 1043567-32-3 This article mentions the following:

In the presence of [Ru(p-cymene)I₂]₂ and the nonracemic binaphthyldiol phosphoric acid I, Hantzsch ester II was used in catalytic amounts with hydrogen as the stoichiometric reductant for the enantioselective transfer hydrogenation of arylbenzoxazinones III (R = Ph, 4-MeOC₆H₄, 4-MeC₆H₄, 3,4-Me₂C₆H₃, 4-ClC₆H₄, 4-BrC₆H₄, 4-FC₆H₄, 3-FC₆H₄, 2-thienyl; R¹ = H, Cl, Me, Me₃C; R² = H, Me) to give the corresponding aryldihydrobenzoxazinones IV (R = Ph, 4-MeOC₆H₄, 4-MeC₆H₄, 3,4-Me₂C₆H₃, 4-ClC₆H₄, 4-BrC₆H₄, 4-FC₆H₄, 3-FC₆H₄, 2-thienyl; R¹ = H, Cl, Me, Me₃C; R² = H, Me) in 59-98% yields and in 92-99% 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: 1043567-32-3Application 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. 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. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Application of 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic Asymmetric Dearomatization of Indolyl Dihydropyridines through an Enamine Isomerization/Spirocyclization/Transfer Hydrogenation Sequence was written by Xia, Zi-Lei;Zheng, Chao;Wang, Shou-Guo;You, Shu-Li. And the article was included in Angewandte Chemie, International Edition in 2018.SDS of cas: 1043567-32-3 This article mentions the following:

A highly efficient synthesis of enantioenriched spiroindolines, e. g., I, by catalytic asym. dearomatization of indolyl dihydropyridines through a chiral phosphoric acid catalyzed enamine isomerization/spirocyclization/transfer hydrogenation sequence has been developed. This reaction proceeds under mild reaction conditions, affording novel spiroindolines in good yields (up to 88 %) with excellent enantioselectivity (up to 97 % ee). DFT calculations provide insights into the reaction mechanism as well as the origin of stereochem. 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: 1043567-32-3SDS of cas: 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. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.SDS of cas: 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Organocatalytic synthesis of α-quaternary amino acid derivatives via aza-Friedel-Crafts alkylation of indoles with simple α-amidoacrylates was written by Righi, Marika;Bartoccini, Francesca;Lucarini, Simone;Piersanti, Giovanni. And the article was included in Tetrahedron in 2011.Electric Literature of C48H29O4P This article mentions the following:

The first (organo)catalytic method for regio- and chemoselective aza-Friedel-Crafts (FC) alkylation of indoles and pyrroles with com. available Me α-acetamidoacrylates has been discovered. It minimizes/eliminates common competing reactions that occur due to the high and multiatom-nucleophilic character of indole and pyrrole. Diverse quaternary α-amino acids were successfully prepared in good yield and high selectivity using low catalyst loading. The enantioselective variant using BINOL-derived phosphoric acids was also explored with indole providing the desired FC alkylation product with moderate enantioselectivities. 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. 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.Electric Literature of C48H29O4P

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

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