Chiral phosphine ligands

An Enantioselective Total Synthesis of (-)-Isoschizogamine was written by Xu, Zhengren;Bao, Xu;Wang, Qian;Zhu, Jieping. And the article was included in Angewandte Chemie, International Edition in 2015.Product Details of 1006708-91-3 This article mentions the following:

A concise enantioselective total synthesis of (-)-isoschizogamine, a complex bridged polycyclic monoterpene indole alkaloid, was accomplished. N-Alkylation of an enantio-enriched imine with an alkyl iodide afforded an iminium salt, which, upon heating by microwave irradiation in the presence of pivalic acid, was converted into the hexacyclic structure of natural product by a complex but ordered domino sequence. The one-pot process leading to the formation of one C-C bond and three C-N bonds created three rings and three contiguous stereogenic centers with complete control of both the relative and absolute stereochem. In the experiment, the researchers used many compounds, for example, (R)-2-(2-(Bis(4-(trifluoromethyl)phenyl)phosphino)-5-(trifluoromethyl)phenyl)-4-(tert-butyl)-4,5-dihydrooxazole (cas: 1006708-91-3Product Details of 1006708-91-3).

(R)-2-(2-(Bis(4-(trifluoromethyl)phenyl)phosphino)-5-(trifluoromethyl)phenyl)-4-(tert-butyl)-4,5-dihydrooxazole (cas: 1006708-91-3) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Product Details of 1006708-91-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

New chiral ferrocenyl P,S-ligands for highly diastereo-/enantioselective catalytic [3 + 2] cycloaddition of azomethine ylides with cyclic and acyclic enones was written by Zhang, Cheng;Yu, Sai-Bo;Hu, Xiang-Ping;Wang, Dao-Yong;Zheng, Zhuo. And the article was included in Organic Letters in 2010.Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine This article mentions the following:

A new family of chiral ferrocenyl P,S-ligands I (R = Me, i-Pr, Ph, 4-ClC₆H₄, 4-MeC₆H₄, PhCH₂) has been developed and successfully applied in a highly endo-selective catalytic asym. cycloaddition of azomethine ylides with various enones, including cyclic and acyclic α-enones. For cyclic α-enones, [Cu(CH₃CN)₄]ClO₄/(R_c,S_Fc)-I (R = i-Pr) complex catalyzed the cycloaddition to give the sole endo-cycloadducts in perfect enantioselectivities (normally 99% ee), while AgOAc/(R_c,S_Fc)-I (R = i-Pr) catalytic system exhibited good endo/exo selectivities (endo/exo = 91/9 to 96/4) and high enantiocontrol (up to 98% ee) for acyclic α-enones. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine).

(R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Bifunctional ferrocene-based squaramide-phosphine as an organocatalyst for highly enantioselective intramolecular Morita-Baylis-Hillman reaction was written by Zhang, Xiaorui;Ma, Pengfei;Zhang, Dongxu;Lei, Yang;Zhang, Shengyong;Jiang, Ru;Chen, Weiping. And the article was included in Organic & Biomolecular Chemistry in 2014.Electric Literature of C26H28FeNP This article mentions the following:

This work demonstrates that, in accord with metal catalysis, ferrocene could be an excellent scaffold for organocatalysts. The simple and easily accessible bifunctional ferrocene-based squaramide-phosphine shows high enantioselectivity in the intramol. Morita-Baylis-Hillman reaction of 7-aryl-7-oxo-5-heptenals, giving a variety of 2-aroyl-2-cyclohexenols in up to 96% ee. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Electric Literature of C26H28FeNP).

(R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2) belongs to chiral phosphine ligands. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Electric Literature of C26H28FeNP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Copper(I) Alkoxide-Catalyzed Alkynylation of Trifluoromethyl Ketones was written by Motoki, Rie;Kanai, Motomu;Shibasaki, Masakatsu. And the article was included in Organic Letters in 2007.Related Products of 352655-61-9 This article mentions the following:

A general method for direct alkynylation of trifluoromethyl ketones to afford the corresponding tertiary propargyl alcs., e.g., I, was developed using CuO^tBu-xantphos or phenanthroline complexes as catalysts. The ligands significantly enhanced the catalyst activity. In addition, KOTf, generated in the catalyst preparation step, exhibited some acceleration effects. A preliminary extension to a catalytic enantioselective CF₃-substituted tertiary propargyl alc. synthesis (up to 52% ee) is also described. 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: 352655-61-9Related Products of 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. 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. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Related Products of 352655-61-9

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Rhodium-Catalyzed Asymmetric [2 + 2 + 2] Cyclization of 1,6-Enynes with Aliphatic and Aromatic Alkenes was written by Ueda, Hiroki;Masutomi, Koji;Shibata, Yu;Tanaka, Ken. And the article was included in Organic Letters in 2017.Name: (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) This article mentions the following:

It has been established that a cationic rhodium(I)/(R)-MeO-BIPHEP complex catalyzes the asym. [2 + 2 + 2] cyclization of 1,6-enynes with aliphatic and aromatic alkenes to produce chiral cyclic dienes through β-hydride elimination from rhodacycle intermediates. Thus, obtained chiral cyclic dienes could be converted to chiral spirocompounds without racemization. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Name: (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine)).

(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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Name: (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium Catalyzed Kinetic and Dynamic Kinetic Asymmetric Transformations of γ-Acyloxybutenolides. Enantioselective Total Synthesis of (+)-Aflatoxin B₁ and B_2a was written by Trost, Barry M.;Toste, F. Dean. And the article was included in Journal of the American Chemical Society in 2003.Related Products of 174810-09-4 This article mentions the following:

The reaction of γ-tert-butoxycarbonyloxy-2-butenolide with phenol nucleophiles in the presence of a Pd(0) complex with chiral ligands may be performed under conditions that favor either a kinetic resolution or a kinetic asym. transformation (KAT) or dynamic kinetic asym. transformation (DYKAT). Performing the reaction at high concentration (0.5 M) in the presence of a carbonate base favors the former, i.e., KAT; whereas, running the reaction at 0.1M in the presence of tetra-n-butylammonium chloride favors the DYKAT process. Syntheses of aflatoxin B₁ (I) and B_2a (II) employs the DYKAT to introduce the stereochem. Starting with Pechmann condensation of the monomethyl ether of phloroglucinol, the requisite phenol nucleophile is constructed in two steps. The DYKAT proceeds with > 95% ee. A reductive Heck cyclization followed by a lanthanide catalyzed intramol. acylation completes the synthesis of the pentacyclic nucleus in 3 steps. Reduction of the lactone provides aflatoxin B_2a and its dehydration product B₁. This synthetic strategy creates an asym. synthesis of the former in only 7 steps and the latter in 9 steps. Thus, the ultimate synthetic sequence involves butenolide III (Boc = CO₂CMe₃) and 5-methoxybenzene-1,3-diol via pyranones IV (X = H, I), butenolide V, and furofuranones VI, VII and VIII, giving II and then I. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4Related Products of 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. 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 ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Related Products of 174810-09-4

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Interactions of cationic palladium(II)- and platinum(II)-η³-allyl complexes with fluoride: is asymmetric allylic fluorination a viable reaction? was written by Hintermann, Lukas;Lang, Florian;Maire, Pascal;Togni, Antonio. And the article was included in European Journal of Inorganic Chemistry in 2006.Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine This article mentions the following:

The origin of dramatic anion effect on palladium-catalyzed asym. allylic substitution, an improvement of enantioselectivity caused by fluoride additives, was explored by reacting of fluoride anions from different sources with pre-formed palladium and platinum allyl complexes. The complex cations [M(η³-RCH:CHCHR)(L₂-N,P)]⁺ (M = Pd, R = Ph, Cy; RCH:CHCHR = indenyl; M = Pt, R = Ph; L₂ = 3-tert-butyl-1-[1-[2-diphenylphosphinoferrocenyl]ethyl]-1H-pyrazole [PPFPz-3-^tBu]) were prepared as salts with PF₆^– or SbF₆^–. The cations were characterized by NMR spectroscopy in solution and by x-ray crystallog. in the solid state. Their reactions with sources of nucleophilic and “naked” fluoride were investigated by multinuclear NMR spectroscopy. The Pd allyl complexes did not undergo any nucleophilic substitution with concomitant release of allyl fluorides. The dicyclohexylallyl fragment was released as a 1,3-diene, 1-cyclohexyl-3-cyclohexylidene-1-propene, by fluoride-induced elimination, but for other allyl complexes the fluoride anions caused rather non-specific decomposition The complex [Pt(η³-1,3-Ph₂C₃H₃)(L₂-N,P)]PF₆ underwent an anion exchange with Me₄NF to give [Pt(1,3-Ph₂C₃H₃)(L₂-N,P)]F which existed as a mixture of interconverting allyl isomers in solution at ambient temperature For similar bromide salt, [Pt(η³-1,3-Ph₂C₃H₃)(L₂-N,P)]Br, allyl isomerization was slow at ambient temperature Precursors of Pt(0) reacted with 3-bromo-1,3-diphenyl-1-propene to give [Pt₂(μ-Br)₂(η³-1,3-Ph₂C₃H₃)₂] and precursors of Pd(0) underwent oxidative additions with both 3-bromo- and 3-fluoro-1,3-diphenyl-1-propenes to give 1,3-diphenylallyl complexes of Pd(II). Therefore, the nucleophilic attack of fluoride on the allyl fragment of Pd(II) complexes is endergonic and thermodynamically unfavored, and the high energy barrier of this step is difficult to overcome in a catalytic allylic fluorination reaction. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine).

(R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2) 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 phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Thioketone-directed rhodium(I) catalyzed enantioselective C-H bond arylation of ferrocenes was written by Cai, Zhong-Jian;Liu, Chen-Xu;Wang, Qiang;Gu, Qing;You, Shu-Li. And the article was included in Nature Communications in 2019.Formula: C31H32O2P2 This article mentions the following:

Planar chiral ferrocenes have received great attention in both academia and industry. Although remarkable progresses have been made over the past decade, the development of efficient and straightforward methods for the synthesis of enantiopure planar chiral ferrocenes remains highly challenging. Herein, authors report a rhodium(I)/phosphonite catalyzed thioketone-directed enantioselective C-H bond arylation of ferrocenes. Readily available aryl iodides are used as the coupling partners in this transformation, leading to a series of planar chiral ferrocenes in good yields and excellent enantioselectivities (up to 86% yield, 99% ee). Of particular note, heteroaryl coupled ferrocenes, which are difficult to access with previous approaches, can be obtained in satisfactory results. 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: 37002-48-5Formula: C31H32O2P2).

(((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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Formula: C31H32O2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric cyclocarbonylation of 1,6-enynes with cobalt catalysts was written by Schmid, Thomas M.;Consiglio, Giambattista. And the article was included in Tetrahedron: Asymmetry in 2004.Category: chiral-phosphine-ligands This article mentions the following:

Octacarbonyldicobalt or Co(II) salts in the presence of (R)-(6,6′-dimethoxybiphenyl-2,2′-diyl)bis(diphenylphosphine) were active and highly enantioselective catalyst for the cyclocarbonylation of enynes such as 4,4-bis(carboethoxy)hex-6-en-1-yne. The reactivity of both catalytic systems towards cyclocarbonylation increased when the CO pressure was increased. However, when a stoichiometric amount of ligand was used, with respect to the catalyst, the enantioselectivity decreased, but increased again as the ligand-to-Co molar ratio increased. 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. 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.Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Rapid ketone transfer hydrogenation by employing simple, in situ prepared iridium(I) precatalysts supported by “non-N-H” P,N ligands was written by Lundgren, Rylan J.;Stradiotto, Mark. And the article was included in Chemistry – A European Journal in 2008.Quality Control of (R,R)-2,2′-Bis[(R)-(N,N-dimethylamino)(phenyl)methyl]-1,1′-bis(diphenylphosphino)ferrocene This article mentions the following:

The catalytic utility in ketone transfer hydrogenation (TH) of the preformed [Ir(cod)(κ²-2-NMe₂-3-PiPr₂-indene)]⁺X^– ([2a]⁺X^–; X: PF₆, BF₄, and OTf; cod: η⁴-1,5-cyclooctadiene; OTf: trifluoromethanesulfonate), [Ir(cod)(κ²-1-PiPr₂-2-NMe₂-indene)]⁺OTf^– ([2b]⁺OTf^–), [Ir(cod)(κ²-2-NMe₂-3-PiPr₂-indenide)] (3), and [Ir(cod)(κ²-o-tBu₂PC₆H₄NMe₂)]⁺PF₆^– ([4]⁺PF₆^–), and of related mixtures prepared from [{IrCl(cod)}₂] and various P,N-substituted indene or phenylene ligands, was examined Whereas [2a]⁺X^–, [2b]⁺OTf^–, 3, and related in situ prepared Ir catalysts derived from P,N-indenes proved to be generally effective in mediating the reduction of acetophenone to 1-phenylethanol in basic iPrOH at reflux (0.1 mol% Ir; 81-99% conversion) in a preliminary catalytic survey, the structurally related Ir catalysts prepared from (o-R₂PC₆H₄)NMe₂ (R: Ph, iPr, or tBu) outperform the corresponding P,N-indene ligands under similar conditions. In such studies, alteration of the substituents at the donor fragments of the supporting P,N ligand had a pronounced influence on the catalytic performance of the derived catalysts, with ligands featuring bulky dialkylphosphino donors proving to be the most effective. Notably, the crystallog. characterized complex [4]⁺PF₆^–, either preformed or prepared in situ from a mixture of [{IrCl(cod)}₂], NaPF₆, and (o-tBu₂PC₆H₄)NMe₂, proved to be highly effective in mediating the catalytic transfer hydrogenation (TH) of ketones in basic iPrOH, with near quant. conversions for a range of alkyl and/or aryl ketones and with very high turnover-frequency values (up to 230000 h^-1 at > 50% conversion); this thereby enabled the use of Ir loadings ranging from 0.1 to 0.004 mol %. Catalyst mixtures prepared from [{IrCl(cod)}₂], NaPF₆, and the chiral (αS,αS)-1,1′-bis[α-(dimethylamino)benzyl]-(R,R)-2,2′-bis(dicyclohexylphosphino)ferrocene (Cy-Mandyphos) ligand proved capable of mediating the asym. TH of aryl alkyl ketones, including that of the hindered substrate 2,2-dimethylpropiophenone with an efficiency (0.5 mol% Ir; 95% conversion, 95% ee) not documented previously in TH chem. 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: 174467-31-3Quality Control of (R,R)-2,2′-Bis[(R)-(N,N-dimethylamino)(phenyl)methyl]-1,1′-bis(diphenylphosphino)ferrocene).

(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. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.Quality Control of (R,R)-2,2′-Bis[(R)-(N,N-dimethylamino)(phenyl)methyl]-1,1′-bis(diphenylphosphino)ferrocene

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis