Day: December 30, 2022

Catalytic Asymmetric Conjugate Addition of a Borylalkyl Copper Complex for Chiral Organoboronate Synthesis was written by Jang, Won Jun;Yun, Jaesook. And the article was included in Angewandte Chemie, International Edition in 2019.Product Details of 252288-04-3 This article mentions the following:

The authors report the catalytic enantioselective conjugate addition of a borylalkyl Cu nucleophile generated in situ from a 1,1-diborylmethane derivative to α,β-unsaturated diesters. In the presence of a chiral N-heterocyclic carbene (NHC)-Cu catalyst, this method facilitated the enantioselective incorporation of a CH₂Bpin moiety at the β-position of the diesters to yield β-chiral alkyl boronates in up to 86% yield with high enantioselectivity. The alkylboron moiety in the resulting chiral diester products was converted into various functional groups by organic transformation of the C-B bond. 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: 252288-04-3Product Details 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. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Product Details of 252288-04-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalyst-Controlled Diastereodivergent Construction of Vicinal Sulfur-Functionalized Quaternary and Tertiary Stereocenters was written by Zhang, Lili;Yuan, Huijun;Lin, Wei;Cheng, Yuyu;Li, Pengfei;Li, Wenjun. And the article was included in Organic Letters in 2018.Synthetic Route of C48H29O4P This article mentions the following:

A catalyst-controlled diastereodivergence is described for the enantioselective conjugate addition of o-hydroxyphenyl-substituted p-QMs with 5H-thiazol-4-ones. The reactions were enabled by two chiral complementary, nonenantiomeric catalysts to furnish a series of adducts possessing vicinal sulfur-functionalized quaternary and tertiary stereocenters in high yields with excellent asym. induction. Moreover, o-QMs generated in situ from o-hydroxybenzyl alcs. were also compatible. 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. 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. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Synthetic Route of C48H29O4P

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Amino Acid Based Phosphoramidite Ligands for the Rhodium-Catalyzed Asymmetric Hydrogenation was written by Breuil, Pierre-Alain R.;Reek, Joost N. H.. And the article was included in European Journal of Organic Chemistry in 2009.Name: (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine This article mentions the following:

Two sets of amino acid based phosphoramidite ligands with either a BINOL backbone (S_b–1a–e and R_b–1b) or a flexible biphenol backbone (2a–c and 2f) were synthesized and evaluated in the rhodium-catalyzed hydrogenation of different functionalized alkenes: di-Me itaconate (3), Me 2-acetamidoacrylate (4), Me α-acetamidocinnamate (5) and N-(3,4-dihydro-2-naphthalenyl)acetamide (6). The amino acid fragment can be modified at three positions (R¹-R³) giving rise to modular ligands. Initial experiments varying the R¹ position of the amino acid fragment, showed that the valine-based phosphoramidite ligand S_b–1b forms the most selective rhodium catalyst for three of the four substrates of the current study. The modifications at the other positions (R² and R³) tweaked the ligand structure such that enhanced selectivities were obtained; up to 97 % ee is obtained for the asym. hydrogenation of 4 with S_b–1e. For ligands with two sources of chirality match/mismatch effects are observed, the diastereoisomer S_b–1b giving higher selectivity than the diastereoisomer R_b–1b for most of the substrates. The set of phosphoramidite ligands having the flexible and cheap biphenol backbone is developed to study the ability of the amino acid derivatives as the sole source of chirality in the ligand to steer enantioselectivity in rhodium-catalyzed hydrogenation. This study shows their capacity to compete with their BINOL-based analogs and even to outclass them depending on the substrate evaluated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009). 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: 252288-04-3Name: (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine).

(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.Name: (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic asymmetric and stereo-divergent oligonucleotide synthesis was written by Featherston, Aaron L.;Kwon, Yongseok;Pompeo, Matthew M.;Engl, Oliver D.;Leahy, David K.;Miller, Scott J.. And the article was included in Science (Washington, DC, United States) in 2021.Quality Control 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:

We report the catalytic stereocontrolled synthesis of dinucleotides. Chiral phosphoric acid (CPA) catalysts are demonstrated to control the formation of stereogenic phosphorous centers during phosphoramidite transfer for the first time. Unprecedented levels of diastereo-divergence are also demonstrated, enabling access to either phosphite diastereomer. Notably, two different CPA scaffolds prove essential for achieving stereo-divergence: peptide-embedded phosphothreonine-derived CPAs, which reinforce and amplify the inherent substrate preference, and C₂-sym. BINOL-derived CPAs, which completely overturn this stereochem. preference. The presently reported catalytic method does not require stoichiometric activators or chiral auxiliaries and enables asym. catalysis with readily available phosphoramidites. The method was applied to the stereocontrolled synthesis of diastereomeric dinucleotides as well as cyclic dinucleotides (CDNs) which are of broad interest in immono-oncol. as agonists of the STING pathway. 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: 1043567-32-3Quality Control 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. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.Quality Control 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

New chiral phosphorus catalysts derived from (S)-binaphthol for highly enantioselective reduction of acetophenone by borane was written by Ma, Margaret F. P.;Li, Kangying;Zhou, Zhenghong;Tang, Chuchi;Chan, Albert S. C.. And the article was included in Tetrahedron: Asymmetry in 1999.Electric Literature of C24H22NO2P This article mentions the following:

New chiral (+)-2,2′-O,O-(1,1′-binaphthyl)-dioxo-N,N-diethylphospholidine 1 and its borane complex 3 were prepared from (S)-binaphthol and their use as catalysts in enantioselective borane reductions of prochiral acetophenone were investigated. Enantiomeric excesses of up to 98.5% have been obtained using 6 mol% of 1 at room temperature and using 6 mol% of 3 at 100°. 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: 252288-04-3Electric Literature of C24H22NO2P).

(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. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Electric Literature of C24H22NO2P

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective cooperative triple catalysis: unique roles of Au(I)/amine/chiral Bronsted acid catalysts in the addition/cycloisomerization/transfer hydrogenation cascade was written by Patil, Nitin T.;Raut, Vivek S.;Tella, Ramesh Babu. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2013.SDS of cas: 1043567-32-3 This article mentions the following:

An enantioselective cooperative process involving the concerted/simultaneous action of three different catalysts i.e. Au(i)/amine/chiral Bronsted acid catalysts has been realized for the synthesis of 2-substituted tetrahydroquinolines from 2-aminobenzaldehydes and terminal alkynes. 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. 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. 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

Highly Enantioselective Conjugate Additions of Potassium Organotrifluoroborates to Enones by Use of Monodentate Phosphoramidite Ligands was written by Duursma, Ate;Boiteau, Jean-Guy;Lefort, Laurent;Boogers, Jeroen A. F.;De Vries, Andre H. M.;De Vries, Johannes G.;Minnaard, Adriaan J.;Feringa, Ben L.. And the article was included in Journal of Organic Chemistry in 2004.Application of 252288-04-3 This article mentions the following:

The use of phosphoramidite ligands in the rhodium-catalyzed asym. conjugate addition of potassium organotrifluoroborates to various enones in the absence of water is described. A systematic search for effective catalysts has been performed by use of high-throughput screening methods. Initially, reaction conditions and catalyst precursors, and ligand libraries were screened. In the next stage a monodentate ligand combination approach was used, and finally a library of 96 different phosphoramidites was prepared by parallel synthesis using a robot (instant ligand libraries) and these were tested in the vinylation of cyclohexenone (up to 88% enantiomeric excess, ee) and 4-phenyl-3-buten-2-one (up to 42% ee). Arylation of cyclohexenone by use of potassium (phenyl)trifluoroborate gave 3-phenylcyclohexanone with 99% ee. 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: 252288-04-3Application 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. 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.Application of 252288-04-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective Conjugate Addition Catalyzed by a Copper Phosphoramidite Complex: Computational and Experimental Exploration of Asymmetric Induction was written by Ardkhean, Ruchuta;Roth, Philippe M. C.;Maksymowicz, Rebecca M.;Curran, Alex;Peng, Qian;Paton, Robert S.;Fletcher, Stephen P.. And the article was included in ACS Catalysis in 2017.HPLC of Formula: 252288-04-3 This article mentions the following:

The stereochem. role of the phosphoramidite ligand in the asym. conjugate addition of alkylzirconium species to cyclic enones has been established through exptl. and computational studies. Systematic, synthetic variation of the modular ligand established that the configuration of the binaphthol backbone is responsible for absolute stereocontrol, whereas modulation of the amido substituents leads to dramatic variations in the level of asym. induction. Chiral amido substituents are not required for enantioselectivity, leading to the discovery of a new family of easily synthesized phosphoramidites based on achiral amines that deliver equal levels of selectivity to Feringa’s ligand. A linear correlation between the length of the aromatic amido groups and exptl. determined enantioselectivity was uncovered for this class of ligand, which, following an optimization, led to highly selective ligands (up to 94% ee) with naphthyl rather than Ph groups. An electronic effect of sterically similar aromatic substituents was investigated through NMR and DFT studies, showing that electron-rich aryl groups allow better Cu coordination. An interaction between the metal center and an aromatic group is responsible for this enhanced affinity and leads to a more tightly coordinated transition structure, leading to the major enantiomer. These studies illustrate the use of parametric quant. structure-selectivity relationships to generate mechanistic models for asym. induction and catalyst structures that may be further probed by experiment and computation. This integrated approach leads to the rational modification of chiral ligands to achieve enhanced levels of selectivity. 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. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.HPLC of Formula: 252288-04-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

New chiral phosphorus catalysts derived from (S)-binaphthol for highly enantioselective reduction of acetophenone by borane. [Retraction of document cited in CA132:35822] was written by Ma, M. F. P.;Li, K.;Zhou, Z.;Tang, C.;Chan, A. S. C.. And the article was included in Tetrahedron: Asymmetry in 2000.Safety of (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine This article mentions the following:

Retraction at the request of the authors who have not been able to reproduce the results reported in the manuscript. 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: 252288-04-3Safety of (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine).

(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. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.Safety of (11bS)-N,N-Diethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-amine

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric spiroacetalization catalysed by confined Bronsted acids was written by Coric, Ilija;List, Benjamin. And the article was included in Nature (London, United Kingdom) in 2012.Product Details of 1043567-32-3 This article mentions the following:

Acetals are mol. substructures that contain two oxygen-carbon single bonds at the same carbon atom, and are used in cells to construct carbohydrates and numerous other mols. A distinctive subgroup are spiroacetals, acetals joining two rings, which occur in a broad range of biol. active compounds, including small insect pheromones and more complex macrocycles. Despite numerous methods for the catalytic asym. formation of other commonly occurring stereocenters, there are few approaches that exclusively target the chiral acetal center and none for spiroacetals. Here we report the design and synthesis of confined Bronsted acids based on a C2-sym. imidodiphosphoric acid motif, enabling a catalytic enantioselective spiroacetalization reaction. These rationally constructed Bronsted acids possess an extremely sterically demanding chiral microenvironment, with a single catalytically relevant and geometrically constrained bifunctional active site. Our catalyst design is expected to be of broad utility in catalytic asym. reactions involving small and structurally or functionally unbiased substrates. 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. 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. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Product Details of 1043567-32-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis