Month: February 2023

Ligand-Substrate Dispersion Facilitates the Copper-Catalyzed Hydroamination of Unactivated Olefins was written by Lu, Gang;Liu, Richard Y.;Yang, Yang;Fang, Cheng;Lambrecht, Daniel S.;Buchwald, Stephen L.;Liu, Peng. And the article was included in Journal of the American Chemical Society in 2017.Category: chiral-phosphine-ligands This article mentions the following:

The current understanding of ligand effects in transition metal catalysis is mostly based on the anal. of catalyst-substrate through-bond and through-space interactions, with the latter commonly considered to be repulsive in nature. The dispersion interaction between the ligand and the substrate, a ubiquitous type of attractive noncovalent interaction, is seldom accounted for in the context of transition-metal-catalyzed transformations. Herein we report a computational model to quant. analyze the effects of different types of catalyst-substrate interactions on reactivity. Using this model, we show that in the copper(I) hydride (CuH)-catalyzed hydroamination of unactivated olefins, the substantially enhanced reactivity of copper catalysts based on bulky bidentate phosphine ligands originates from the attractive ligand-substrate dispersion interaction. These computational findings are validated by kinetic studies across a range of hydroamination reactions using structurally diverse phosphine ligands, revealing the critical role of bulky P-aryl groups in facilitating this process. 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: 352655-61-9Category: chiral-phosphine-ligands).

(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. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Total synthesis of the antimalarial naphthylisoquinoline alkaloid 5-epi-4′-O-demethylancistrobertsonine C by asymmetric Suzuki cross-coupling was written by Bringmann, Gerhard;Ruedenauer, Stefan;Bruhn, Torsten;Benson, Lauren;Brun, Reto. And the article was included in Tetrahedron in 2008.COA of Formula: C26H28FeNP This article mentions the following:

The first total synthesis of the antimalarial naphthylisoquinoline alkaloid 5-epi-4′-O-demethylancistrobertsonine C (I) and its-as yet unnatural-atropo-diastereomer is described. The key step of the synthesis is the construction of the rotationally hindered and thus stereogenic biaryl axis, which was built up by a Suzuki reaction. The use of chiral ligands in the palladium-catalyzed cross-coupling permitted to increase the low internal asym. induction up to a diastereomeric ratio of 74:26. The assignment of the axial configurations of the atropo-diastereomers was achieved by 2D NMR experiments and corroborated by quantum chem. CD calculations In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2COA of Formula: C26H28FeNP).

(R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2) 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. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.COA of Formula: C26H28FeNP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Compromise between conjugation length and charge-transfer in nonlinear optical η⁵-monocyclopentadienyliron(II) complexes with substituted oligo-thiophene nitrile ligands: Synthesis, electrochemical studies and first hyperpolarizabilities was written by Garcia, M. Helena;Mendes, Paulo J.;Robalo, M. Paula;Dias, A. Romao;Campo, Jochen;Wenseleers, Wim;Goovaerts, Etienne. And the article was included in Journal of Organometallic Chemistry in 2007.Recommanded Product: 37002-48-5 This article mentions the following:

A series of half-sandwich η⁵-cyclopentadienyliron(II) diphosphine complexes with substituted oligo-thiophene carbonitrile ligands, [FeCp(P-P)(NC{SC₄H₂}_nNO₂)][PF₆] (1a–3a, P-P = dppe; 1b–3b, P-P = (+)-diop; n = 1-3) was prepared by complexation of the nitrile ligands to the corresponding iodides, [FeCp(P-P)I]. The electrochem. behavior of the new compounds was explored by cyclic voltammetry. The compounds 1–3 exhibit pos. solvatochromism, i.e., a bathochromic shift in more polar solvents. Quadratic hyperpolarizabilities (β) of the complexes with dppe co-ligands have been determined by hyper-Rayleigh scattering (HRS) measurements at two fundamental wavelengths of 1.064 and 1.550 μm, to uncover the two-photon resonance effect and to estimate static β values. The obtained overall results are found to be better than for the related η⁵-monocyclopentadienyliron(II) complexes with p-benzonitrile derivatives Although an increase of the resonant β at 1.064 μm with increasing number of thiophene units in the conjugated ligand was found (up to 910 × 10^-30 esu), the static values β₀ remain practically unchanged, as shown by the 1.550 μm measurements. Combined with the electrochem. and spectroscopic data (IR, NMR, UV-vis), this remarkable evolution of β shows that the increase of conjugation length is balanced by a decrease in charge-transfer efficiency. 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: 37002-48-5Recommanded Product: 37002-48-5).

(((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) (cas: 37002-48-5) 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.Recommanded Product: 37002-48-5

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium-catalysed intramolecular asymmetric cyclohydroaryloxycarbonylation of 2-allylphenol derivatives. Synthesis of chiral lactones via cyclocarbonylation was written by Abu Seni, Anas;Kollar, Laszlo;Pongracz, Peter. And the article was included in Molecular Catalysis in 2020.Related Products of 37002-48-5 This article mentions the following:

Homogeneous catalytic hydroaryloxycarbonylation of 2-allylphenol derivatives I (R¹ = H, CH₃, OCH₃, CHO; R² = H, COCH₃) was performed using palladium complexes toward the corresponding lactones II, III, IV. Reactions were conducted under carbon monoxide atm. in the absence of hydrogen gas. Palladium catalyst was generated in situ, using various phosphine ligands e.g., (4S,5S)-4,5-bis(diphenylphosphinomethyl)-2,2-dimethyl-1,3-dioxolane and precursors as Pd(OAc)₂, PdCl₂, PdCl₂(PhCN)₂, etc. in the presence of acid additives as HCl, HCOOH, TsOH, etc. In general, chiral 6- III and achiral 7-membered lactones IV were formed dominantly, only trace amounts of the 5-membered lactone II can be identified. Moderate or good enantioselectivity can be achieved using chiral ligands regarding the 6-membered chromanone derivatives III. The regioselectivity of the reaction is particularly effected by catalyst composition and acid co-catalysts and found to be insensitive for substrate substitution. 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: 37002-48-5Related Products of 37002-48-5).

(((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. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Related Products of 37002-48-5

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioface-Selective Palladium-Catalyzed Silaboration of Allenes via Double Asymmetric Induction was written by Suginome, Michinori;Ohmura, Toshimichi;Miyake, Yoshihiro;Mitani, Shin’ichirou;Ito, Yoshihiko;Murakami, Masahiro. And the article was included in Journal of the American Chemical Society in 2003.Computed Properties of C33H25OP This article mentions the following:

Enantioenriched β-borylallylsilanes, e.g., (RO)₂BC(:CH₂)CH(SiMe₂Ph)CH₂CH₂Ph [(RO)₂B = 4,5-diorgano-1,3,2-dioxaborolanyl], were synthesized by Pd-catalyzed enantioface-selective addition of the Si-B bond of chiral 2-dimethylsilyl-4,5-diorgano-1,3,2-dioxaborolane (e.g., organo = Me, Ph, CO₂Prⁱ) to terminal allenes, CH₂:C:CHCH₂CH₂Ph, using a Pd catalyst possessing a chiral monodentate phosphine ligand, e.g., CpPd(allyl)/PPh₃. Use of a silylborane bearing a chiral auxiliary on the B atom was beneficial to gain enantioface selectivities ≤96% de. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Computed Properties of C33H25OP).

(S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9) 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. Computed Properties of C33H25OP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Practical Synthesis of MDM2 Antagonist RG7388. Part 1: A Cu(II)-Catalyzed Asymmetric [3 + 2] Cycloaddition was written by Shu, Lianhe;Gu, Chen;Fishlock, Dan;Li, Zizhong. And the article was included in Organic Process Research & Development in 2016.Computed Properties of C38H32O2P2 This article mentions the following:

An efficient asym. synthesis of MDM2 antagonist RG7388 (I) is reported. The highly functionalized chiral pyrrolidine carboxamate was assembled via a Cu(OAc)₂/(R)-BINAP catalyzed asym. [3+2] cycloaddition, which gave the exo and endo adducts in a ratio of 10:1, with high enantiomeric excess for the exo isomer. A one pot hydrolysis and retro-Mannich/Mannich isomerization of the cycloaddition adducts in the presence of aqueous sodium hydroxide afforded RG7388 in high chem. and enantiomeric purities and 69% overall yield. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Computed Properties of C38H32O2P2).

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

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Cu(I)-Ming-phos Catalyzed Enantioselective [3+2] Cycloadditions of Glycine ketimines to β-Trifluoromethyl Enones was written by Liu, Bing;Zhang, Zhan-Ming;Xu, Bing;Xu, Shan;Wu, Hai-Hong;Zhang, Junliang. And the article was included in Advanced Synthesis & Catalysis in 2018.Related Products of 2222798-18-5 This article mentions the following:

A catalytic asym. [3+2] cycloaddition of glycine ketimines with β-CF₃ β,β-disubstituted enones was realized in the presence of a chiral copper(I)/Ming-Phos complex. This method provided an access to construct highly functionalized pyrrolidines e.g.,I, bearing three contiguous stereocenters, which including a trifluoromethylated all-carbon quaternary stereocenter. The features of this reaction included high chemo-, diastereo-, enantioselectivity (up to > 20:1 cr, > 20:1 dr, 98% ee), readily available starting materials, well functional-group tolerance and mild reaction conditions. Control experiments demonstrated that the fluoro-substituent was crucial for the reactivity. In the experiment, the researchers used many compounds, for example, (R)-N-((R)-(2-(Diphenylphosphino)phenyl)(phenyl)methyl)-N,2-dimethylpropane-2-sulfinamide (cas: 2222798-18-5Related Products of 2222798-18-5).

(R)-N-((R)-(2-(Diphenylphosphino)phenyl)(phenyl)methyl)-N,2-dimethylpropane-2-sulfinamide (cas: 2222798-18-5) 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 2222798-18-5

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Achieving Chemo-, Regio-, and Stereoselectivity in Palladium-Catalyzed Reaction of γ-Borylated Allylic Acetates was written by Kukkadapu, Krishna Kishore;Ouach, Aziz;Lozano, Pedro;Vaultier, Michel;Pucheault, Mathieu. And the article was included in Organic Letters in 2011.Reference of 174810-09-4 This article mentions the following:

Three-carbon highly functionalized γ-borylated allylic acetates underwent a regio- and stereocontrolled Tsuji-Trost reaction in the presence of palladium complexes. An ipso substitution of the acetate with complete stereoretention of the chiral center was achieved, leading to vinylic boronates with enantiomeric excesses above 99%. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4Reference 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. 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. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Reference of 174810-09-4

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric Rh(I)-catalyzed intramolecular [3 + 2] cycloaddition of 1-yne-vinylcyclopropanes for bicyclo[3.3.0] compounds with a chiral quaternary carbon stereocenter and density functional theory study of the origins of enantioselectivity was written by Lin, Mu;Kang, Guan-Yu;Guo, Yi-An;Yu, Zhi-Xiang. And the article was included in Journal of the American Chemical Society in 2012.Category: chiral-phosphine-ligands This article mentions the following:

A highly enantioselective Rh(I)-catalyzed intramol. [3 + 2] cycloaddition of 1-yne-VCPs to bicyclo[3.3.0] compounds with an all-carbon chiral quaternary stereocenter at the bridgehead carbon was developed. DFT calculations of the energy surface of the catalytic cycle (complexation, cyclopropane cleavage, alkyne insertion, and reductive elimination) of the asym. [3 + 2] cycloaddition reaction indicated that the rate- and stereo-determining step is the alkyne-insertion step. Anal. of the alkyne-insertion transition states revealed that the serious steric repulsion between the substituents in the alkyne moiety of the substrates and the rigid H₈-BINAP backbone is responsible for not generating the disfavored [3 + 2] cycloadducts. 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. 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. Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Iridium Catalysts with f-Amphox Ligands: Asymmetric Hydrogenation of Simple Ketones was written by Wu, Weilong;Liu, Shaodong;Duan, Meng;Tan, Xuefeng;Chen, Caiyou;Xie, Yun;Lan, Yu;Dong, Xiu-Qin;Zhang, Xumu. And the article was included in Organic Letters in 2016.COA of Formula: C26H28FeNP This article mentions the following:

A series of modular and rich electronic tridentate ferrocene aminophosphoxazoline ligands (f-amphox) have been successfully developed and used in iridium-catalytic asym. hydrogenation of simple ketones to afford corresponding enantiomerically enriched alcs. under mild conditions with superb activities and excellent enantioselectivities (up to 1,000,000 TON, almost all products up to >99% ee, full conversion). The resulting chiral alcs. and their derivatives are important intermediates in pharmaceuticals. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2COA of Formula: C26H28FeNP).

(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. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.COA of Formula: C26H28FeNP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis