Month: February 2023

Defined rhodium-MandyPhos pre-catalyst systems was written by Nass, Andreas Rivas;Doppiu, Angelino;Karch, Ralf;Schuster, Andreas;Stephen, A.;Hashmi, K.. And the article was included in Chimica Oggi in 2009.Reference of 174467-31-3 This article mentions the following:

Investigations of Ru- and Rh-based chiral hydrogenation reactions using the ligands MandyPhos and TaniaPhos are up to now based on in situ protocols. The purpose of this and prior work was the clear and detailed structural description of isolated rhodium and ruthenium pre-catalysts with these ligands in order to develop defined ready to use catalytic systems for asym. synthesis. In the case of ruthenium it was found that it is possible to isolate and identify well-defined pre-catalyst systems only by establishing new protocols for complex synthesis. Driven by those experiences, the coordination behavior of MandyPhos with rhodium was investigated and a similar picture emerged. This study provides new synthetic routes to stable rhodium complexes with MandyPhos ligands and norbornadiene or cyclooctadiene ancillary ligands. 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: 174467-31-3Reference of 174467-31-3).

(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. 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.Reference of 174467-31-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Exercising Regiocontrol in Palladium-Catalyzed Asymmetric Prenylations and Geranylation: Unifying Strategy toward Flustramines A and B was written by Trost, Barry M.;Malhotra, Sushant;Chan, Walter H.. And the article was included in Journal of the American Chemical Society in 2011.Recommanded Product: 174810-09-4 This article mentions the following:

Pd-catalyzed asym. prenylation of oxindoles to afford selectively either the prenyl or reverse-prenyl products, e.g. I and II, has been demonstrated. Control of the regioselectivity in this transformation is governed by the choice of ligand, solvent, and halide additive. The resulting prenylated and reverse-prenylated products were transformed into ent-flustramides and ent-flustramines A and B. Addnl., control of the regio- and diastereoselectivity was obtained using π-geranylpalladium complexes. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4Recommanded Product: 174810-09-4).

N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Recommanded Product: 174810-09-4

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Cobalt-Catalyzed Asymmetric Addition of Silylacetylenes to 1,1-Disubstituted Allenes was written by Sawano, Takahiro;Ou, Keiyu;Nishimura, Takahiro;Hayashi, Tamio. And the article was included in Journal of Organic Chemistry in 2013.Product Details of 360048-63-1 This article mentions the following:

The asym. addition of silylacetylenes to 1,1-disubstituted allenes proceeded in the presence of a Co/chiral bisphosphine ligand to give the corresponding enynes with high enantioselectivity. E.g., reaction of (4-MeOC₆H₄)CMe:C:CH₂ with ⁱPr₃SiCCH in the presence of 5 mol% Co(OAc)₂·4H₂O/5 mol% dppe/50 mol% Zn in DMSO at 80° gave 89% yield of (4-MeOC₆H₄)CHMeC(:CH₂)CCSiⁱPr₃ (major isomer). The results of D-labeling experiments indicated that a H atom at the chiral center is originated from the terminal alkyne, and they were in good agreement with the proposed catalytic cycle where enantioselectivity is determined by the reaction of the proposed π-allylcobalt intermediate with the terminal alkyne. In the experiment, the researchers used many compounds, for example, (1R)-1-[Bis(4-methoxy-3,5-dimethylphenyl)phosphino]-2-[(1R)-1-(dicyclohexylphosphino)ethyl]ferrocene (cas: 360048-63-1Product Details of 360048-63-1).

(1R)-1-[Bis(4-methoxy-3,5-dimethylphenyl)phosphino]-2-[(1R)-1-(dicyclohexylphosphino)ethyl]ferrocene (cas: 360048-63-1) 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.Product Details of 360048-63-1

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Novel 1,4-diphosphanes with imidazolidin-2-one backbones as chiral ligands: highly enantioselective Rh-catalyzed hydrogenation of enamides was written by Lee, Sang-Gi;Zhang, Yong Jian;Song, Choong Eui;Lee, Jae Kyun;Choi, Jung Hoon. And the article was included in Angewandte Chemie, International Edition in 2002.Category: chiral-phosphine-ligands This article mentions the following:

Asym. hydrogenation of N-acetyl α-aryl enamides ArC(:CHR¹)NHAc [Ar = (un)substituted Ph; R¹ = H, Me, Et] was catalyzed by [Rh(cod)₂]BF₄ and 1,4-diphosphane ligands I (R = H, Me, Et, etc.). I were prepared from a L-tartaric acid derivative 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: 37002-48-5Category: chiral-phosphine-ligands).

(((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) (cas: 37002-48-5) 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.Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Cascade CuH-catalyzed conversion of alkynes into enantioenriched 1,1-disubstituted products was written by Gao, De-Wei;Gao, Yang;Shao, Huiling;Qiao, Tian-Zhang;Wang, Xin;Sanchez, Brittany B.;Chen, Jason S.;Liu, Peng;Engle, Keary M.. And the article was included in Nature Catalysis in 2020.HPLC of Formula: 352655-61-9 This article mentions the following:

Enantioenriched α-aminoboronic acids play a unique role in medicinal chem. and have emerged as privileged pharmacophores in proteasome inhibitors. Addnl., they represent synthetically useful chiral building blocks in organic synthesis. Recently, CuH-catalyzed asym. alkene hydrofunctionalization has become a powerful tool to construct stereogenic C centers. By contrast, applying CuH cascade catalysis to achieve the reductive 1,1-difunctionalization of alkynes remains an important, but largely unaddressed, synthetic challenge. Herein, the authors report an efficient strategy to synthesize α-aminoboron compounds by a CuH-catalyzed hydroboration/hydroamination cascade of readily available alkynes. Notably, this transformation selectively delivers the desired 1,1-heterodifunctionalized product rather than the alternative homodifunctionalized, 1,2-heterodifunctionalized or reductively monofunctionalized byproducts, thereby offering rapid access to these privileged scaffolds with high chemo-, regio- and enantioselectivity. 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: 352655-61-9HPLC of Formula: 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. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. HPLC of Formula: 352655-61-9

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

A Mixed-Ligand Approach Enables the Asymmetric Hydrogenation of an α-Isopropylcinnamic Acid en Route to the Renin Inhibitor Aliskiren was written by Boogers, Jeroen A. F.;Felfer, Ulfried;Kotthaus, Martina;Lefort, Laurent;Steinbauer, Gerhard;De Vries, Andre H. M.;De Vries, Johannes G.. And the article was included in Organic Process Research & Development in 2007.Recommanded Product: 864529-90-8 This article mentions the following:

An asym. hydrogenation of (E)-2-isopropyl-3-[3-(3-methoxypropoxy)-4-methoxyphenyl]-2-propenoic acid, which affords a chiral intermediate for the renin inhibitor aliskiren, has been developed using a rhodium catalyst ligated with a chiral monodentate phosphoramidite and a nonchiral phosphine. Whereas catalysts based on two equivalent of monodentate phosphoramidites gave promising results, the rate of hydrogenation and ee of the product could be improved spectacularly by the addition of monodentate nonchiral triarylphosphines to these catalysts. This remarkable mixed-ligand catalyst has been identified using high-throughput experimentation. With the best catalysts turnover numbers >5000 mol mol^-1, turnover frequencies >1000 mol mol^-1 h^-1, and ee’s up to 95% have been achieved. In the experiment, the researchers used many compounds, for example, 1-((11bR)-2,6-Dimethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-yl)piperidine (cas: 864529-90-8Recommanded Product: 864529-90-8).

1-((11bR)-2,6-Dimethyldinaphtho[2,1-d:1′,2′-f][1,3,2]dioxaphosphepin-4-yl)piperidine (cas: 864529-90-8) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Recommanded Product: 864529-90-8

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective and Regio-divergent Addition of Purines to Terminal Allenes: Synthesis of Abacavir was written by Thieme, Niels;Breit, Bernhard. And the article was included in Angewandte Chemie, International Edition in 2017.Formula: C42H56FeO2P2 This article mentions the following:

The rhodium-catalyzed atom-economic asym. N-selective intermol. addition of purine derivatives to terminal allenes is reported. Branched allylic purines were obtained in high yields, regioselectivity and outstanding enantioselectivity utilizing a Rh/Josiphos catalyst. Conversely, linear selective allylation of purines could be realized in good to excellent regio- and E/Z-selectivity with a Pd/dppf catalyst system. Furthermore, the new methodol. was applied to a straightforward asym. synthesis of carbocyclic nucleoside abacavir. In the experiment, the researchers used many compounds, for example, (1R)-1-[Bis(4-methoxy-3,5-dimethylphenyl)phosphino]-2-[(1R)-1-(dicyclohexylphosphino)ethyl]ferrocene (cas: 360048-63-1Formula: C42H56FeO2P2).

(1R)-1-[Bis(4-methoxy-3,5-dimethylphenyl)phosphino]-2-[(1R)-1-(dicyclohexylphosphino)ethyl]ferrocene (cas: 360048-63-1) 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. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Formula: C42H56FeO2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic enantioselective addition of phenylboronic acid and phenylboroxine to N-tosylimines: Pd^II and Rh^I catalysis was written by Marques, Carolina S.;Burke, Anthony J.. And the article was included in European Journal of Organic Chemistry in 2010.COA of Formula: C52H44N2O2P2 This article mentions the following:

This is the first account of a successful, Pd^II-catalyzed enantioselective addition of phenylboronic acid to electron-deficient N-tosylarylimines by using chiral diphosphane ligands. A number of com. diphosphane ligands were screened. Despite moderate to good yields, ee values of 99% could be achieved with MeDuPhos. Novel Rh^I catalysts were also screened, and ee values as high as 74% could be obtained. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4COA of Formula: C52H44N2O2P2).

N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.COA of Formula: C52H44N2O2P2

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

Rapid virtual screening of enantioselective catalysts using CatVS was written by Rosales, Anthony R.;Wahlers, Jessica;Lime, Elaine;Meadows, Rebecca E.;Leslie, Kevin W.;Savin, Rhona;Bell, Fiona;Hansen, Eric;Helquist, Paul;Munday, Rachel H.;Wiest, Olaf;Norrby, Per-Ola. And the article was included in Nature Catalysis in 2019.Electric Literature of C38H32O2P2 This article mentions the following:

The development of computational tools to support organic synthesis, including the prediction of reaction pathways, optimization and selectivity, is a topic of intense current interest. Transition state force fields, derived by the quantum-guided mol. mechanics method, rapidly calculate the stereoselectivity of organic reactions accurately enough to allow predictive virtual screening. Here we describe CatVS, an automated tool for the virtual screening of substrate and ligand libraries for asym. catalysis within hours. It is shown for the OsO₄-catalyzed cis-dihydroxylation that the results from the automated set-up are indistinguishable from a manual substrate screen. Predictive computational ligand selection is demonstrated in the virtual ligand screen of a library of diphosphine ligands for the rhodium-catalyzed asym. hydrogenation of enamides. Subsequent exptl. testing verified that the most selective substrate-ligand combinations are successfully identified by the virtual screen. CatVS is therefore a promising tool to increase the efficiency of high-throughput experimentation. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Electric Literature of C38H32O2P2).

(R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1) 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.Electric Literature of C38H32O2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis