Day: February 23, 2023

Highly enantioselective spirocyclization of 1,6-enynes catalyzed by cationic skewphos rhodium(I) complex was written by Mikami, Koichi;Yusa, Yukinori;Hatano, Manabu;Wakabayashi, Kazuki;Aikawa, Kohsuke. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2004.Computed Properties of C29H30P2 This article mentions the following:

A cationic rhodium(I) complex having a skewphos ligand was a highly enantioselective catalyst for asym. carbocyclization of 1,6-enynes. 1,6-Enynes, e.g., I, underwent spirocyclization to give spiro-cycles, e.g., II, with good control of the newly formed quaternary stereogenic centers of the spiro-rings. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Computed Properties of C29H30P2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) 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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Computed Properties of C29H30P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Geminal Dicarboxylates as Carbonyl Surrogates for Asymmetric Synthesis. Part I. Asymmetric Addition of Malonate Nucleophiles was written by Trost, Barry M.;Lee, Chul Bom. And the article was included in Journal of the American Chemical Society in 2001.HPLC of Formula: 174810-09-4 This article mentions the following:

Asym. alkylations of allylic geminal dicarboxylates with dialkyl malonates have been investigated. The requisite allylic geminal dicarboxylates are prepared in good yields and high isomeric purities either by ferric chloride-catalyzed addition of acid anhydrides to α,β-unsaturated aldehydes or by palladium-catalyzed isomerization and addition reactions of propargylic acetates with acetic acid. E.g., treatment of trans-cinnamaldehyde with 5 equivalent in the presence of 0.5% iron (III) chloride gave (E)-PhCH:CHCH(OAc)₂ in 85% yield. E.g., treatment of (S)-MeCH[OSi(Ph)₂CMe₃]CCCH₂OAc with 1.2 equivalent acetic acid and 1 mol% tetrakis(triphenylphosphine)palladium in toluene at 110° gave (E,S)-MeCH[OSi(Ph)₂CMe₃]CH:CCHCH(OAc)₂ in 81% yield. The complex of di(allylchloropalladium) and nonracemic ligands derived from di(2-diphenylphosphinobenzoyl) amides of trans-1,2-diaminocyclohexane most efficiently catalyzed the asym. process to provide allylic carboxylate esters with high ee. E.g., sodium hydride was added to a solution of di-Me 2-methylmalonate and the mixture stirred at ambient temperature until gas evolution ceased; di(allylpalladium chloride), the (R,R)-trans-1,2-diaminocyclohexane di(2-diphenylphosphinobenzoyl) amide, and (E)-PhCH:CHCH(OAc)₂ were added and the mixture was stirred for 2 h to give (R,E)-PhCH:CHCH(OAc)C(Me)(CO₂Me)₂ in 92% yield as a single regioisomer in >95% ee. By systematic optimization studies, factors affecting the enantioselectivity of the reaction have been probed. In general, higher ee’s have been achieved with those conditions which facilitate kinetic capture of the incipient π-allylpalladium intermediate. These conditions also proved effective for achieving high regioselectivities. The minor regioisomeric product was formed when reactive substrates or achiral ligands were employed for the reaction, and could be minimized through the use of the chiral ligand. Under the established conditions, the alkylation of various gem-dicarboxylates afforded monoalkylated products in high yields with greater than 90% ee. The process constitutes the equivalent of an addition of a stabilized nucleophile to a carbonyl group with high asym. induction. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4HPLC of Formula: 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. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.HPLC of Formula: 174810-09-4

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Synthesis, Characterization, and Reactivity of Hydroxycyclopentadienyl Cobalt Complexes was written by Wu, Weiwei;Solis-Ibarra, Diego;Walker, Katherine L.;Waymouth, Robert M.. And the article was included in Organometallics in 2018.Product Details of 77876-39-2 This article mentions the following:

The reaction of tetraphenylcyclopentadienone with Co₂(CO)₈ generates the mixed-valence tricobalt complex [[Ph₄C₄CO]Co(CO)₂]₂[μ-Co(MeCN)₂]. In contrast to the conventional Pauson-Khand reaction to generate cyclopentadienone ligated Co complexes, this method benefits from both mild reaction conditions and high yields. Treatment of this tricobalt complex with proton sources such as H₂O or alcs. yields the monomeric hydroxy-tetraphenylcyclopentadienyl Co complex [Ph₄CpOH]Co(CO)₂. Phosphite substituted monomeric Co complexes [Ph₄CpOH]Co(CO)[P(OR)₃] were also synthesized, and protonation of these complexes transiently formed Co hydride species. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Product Details of 77876-39-2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) 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 77876-39-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

High-Throughput Ligand Screening Enables the Enantioselective Conjugate Borylation of Cyclobutenones to Access Synthetically Versatile Tertiary Cyclobutylboronates was written by Clement, Helen A.;Boghi, Michele;McDonald, Rory M.;Bernier, Louise;Coe, Jotham W.;Farrell, William;Helal, Christopher J.;Reese, Matthew R.;Sach, Neal W.;Lee, Jack C.;Hall, Dennis G.. And the article was included in Angewandte Chemie, International Edition in 2019.Recommanded Product: 77876-39-2 This article mentions the following:

Cyclobutane rings are important in medicinal chem., yet few enantioselective methods exist to access this scaffold. In particular, cyclobutylboronates are receiving increasing attention in the literature due to the synthetic versatility of alkylboronic esters and the increasing role of boronic acids in drug discovery. Herein, a conjugate borylation of α-alkyl,β-aryl/alkyl cyclobutenones is reported leading to the first synthesis of enantioenriched tertiary cyclobutylboronates. Cyclobutanones with two stereogenic centers are obtained in good to high yield, with high enantioselectivity and diastereoselectivity. Vital to this advance are the development of a novel approach to α,β unsym. disubstituted cyclobutenone substrates and the use of a high-throughput chiral ligand screening platform. The synthetic utility of both the boronic ester and ketone functionalities is displayed, with remarkable chemoselectivity for either group being possible in this small ring scaffold. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Recommanded Product: 77876-39-2).

(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Recommanded Product: 77876-39-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric Catalytic Hydrogenolysis of Aryl-Halide Bonds in Fused Arene Chromium and Ruthenium Complexes was written by Mercier, Audrey;Urbaneja, Xavier;Yeo, Wee Chuan;Chaudhuri, Piyali Datta;Cumming, Graham R.;House, David;Bernardinelli, Gerald;Kuendig, E. Peter. And the article was included in Chemistry – A European Journal in 2010.Formula: C26H28FeNP This article mentions the following:

Access to highly enantioenriched planar chiral [Cr(5-bromonaphthalene)(CO)₃] (6), [Ru(η⁵-C₅R₅)(5-bromonaphthalene)][PF₆] (42) and [Ru(η⁵-C₅R₅)(4-bromoindene)] (44) was sought using asym. hydrogenolysis of [Cr(5,8-dibromonaphthalene)(CO)₃] (5), [Ru(η⁵-C₅R₅)(5,8-dibromonaphthalene)] (39) and [Ru(η⁵-C₅R₅)(4,7-dibromoindene)] (40), resp. Initial efforts focused on the chromium complex 5. Pd⁰ catalysts with dimethoxyethane as the solvent and LiBH₄ or NaBH₃CN as a hydride source worked best. Nineteen chiral bidentate phosphorus ligands were screened in this reaction. Asym. induction was low to modest with product ee’s in the range of 4 to 52 % and yields of 6 of up to 70 %. Chiral phosphoramidite ligands proved superior and a bulky ligand derived from a Whitesell amine and 3,3′-diphenyl-binaphthol afforded 6 with an ee of 97%. The high enantioselectivity is largely due to the initial desymmetrization reaction though kinetic resolution also plays an important role as shown by the determination of a selectivity factor s = 8.5 at -10°. Initially high ligand loadings (4 equivalent/Pd) were necessary to achieve good asym. induction. This could be traced to the trapping of the chiral ligand by borane formed in the reaction. Addition of 1,4-diazabicyclo[2.2.2]octane (DABCO) suppressed this, and its addition led to the use of Pd and chiral ligand in a 1:1.2 ratio. Asym. hydrogenolysis of cationic dibromonaphthalene and neutral dibromoindenyl complexes of Ru cyclopentadienyl complexes was investigated and afforded the following results: [RuCp(5-bromonaphthalene)][PF₆] (39a; 75%, 90% ee), [RuCp*(5-bromonaphthalene)][PF₆] (39b; 88%, 99% ee), [RuCp(4-bromoindenyl)] (44a; 72%, 96% ee), and [RuCp*(4-bromoindenyl)] (44b; 62%, 68% ee). In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Formula: C26H28FeNP).

(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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Formula: C26H28FeNP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective synthesis of tertiary α-hydroxyketones from unfunctionalized ketones: palladium-catalyzed asymmetric allylic alkylation of enolates was written by Trost, Barry M.;Koller, Raffael;Schaeffner, Benjamin. And the article was included in Angewandte Chemie, International Edition in 2012.Recommanded Product: N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) This article mentions the following:

A highly regio- and enantioselective palladium-catalyzed decarboxylative allylic alkylation to access functionalized tertiary α-hydroxyketones from ketones is introduced. Starting from tetralone derivatives and benzosuberone, through O-acylation with allyl imidazolecarboxylates followed by epoxidation with m-CPBA, rearrangement by treatment with BF₃·OEt₂, enolationprotection, and palladium-catalyzed asym. allylic alkylation, a series of α-hydroxy benzocyclic ketone derivatives were obtained in good yields and excellent stereoselectivities. Finally, the corresponding α-hydroxy benzocyclic ketones could be generated by romoving the methoxymethyl (MOM) or benzyloxymethyl (BOM) protecting group. 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: N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide)).

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. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.Recommanded Product: N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Copper-Catalyzed Tandem Asymmetric Borylation of β-Chloroalkyl Aryl Ketones and Related Compounds was written by Jiang, Quanbin;Guo, Tenglong;Yu, Zhengkun. And the article was included in ChemCatChem in 2015.Recommanded Product: 174467-31-3 This article mentions the following:

The Cu-catalyzed, one-pot tandem (asym.) borylation of β-chloroalkyl aryl ketones via the in situ generated acyclic enones with bis(pinacolato)diboron was achieved efficiently to reach up to 97% yield and 99% enantioselectivity for the formal sp³ C-Cl borylation products. The present methodol. provides an efficient alternative route to (chiral) alkylboron compounds 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: 174467-31-3Recommanded Product: 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. 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 ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Recommanded Product: 174467-31-3

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Efficient synthesis of chiral 1,3-diols and of 1-substituted-propan-1-ols through asymmetric hydrogenation was written by Touati, Ridha;Ben Hassine, Bechir. And the article was included in Journal de la Societe Chimique de Tunisie in 2008.Application of 133545-16-1 This article mentions the following:

Asym. hydrogenations of an achiral β-keto ester using a chiral diphosphine-ruthenium catalyst to set the hydroxyl function in a stereo controlled manner were used in key-step towards the total synthesis of both enantiomers of secondary alcs. with excellent enantioselectivity (>99% ee) and high yields. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Application of 133545-16-1).

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

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium(II) Complexes of 2-Dimethylamino-2′-diphenylphosphino-1,1′-binaphthyl (MAP) with Unique P,C_σ-Coordination and Their Catalytic Activity in Allylic Substitution, Hartwig-Buchwald Amination, and Suzuki Coupling was written by Kocovsky, Pavel;Vyskocil, Stepan;Cisarova, Ivana;Sejbal, Jan;Tislerova, Iva;Smrcina, Martin;Lloyd-Jones, Guy C.;Stephen, Susanna C.;Butts, Craig P.;Murray, Martin;Langer, Vratislav. And the article was included in Journal of the American Chemical Society in 1999.Formula: C33H25OP This article mentions the following:

Reaction of 2-dimethylamino-2′-diphenylphosphino-1,1′-binaphthyl with (PhCN)₂PdCl₂ gave an unusual C_σ-Pd bonding mode complex I. The catalytic activity in allylic substitution, Hartwig-Buchwald Amination, and Suzuki coupling of I is described. The crystal structure of I and two related complexes were described. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Formula: C33H25OP).

(S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9) 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. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Formula: C33H25OP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Preparation and evaluation of a new synthetic polymeric chiral stationary phase for HPLC based on the trans-9,10-dihydro-9,10-ethanoanthracene-(11S,12S)-11,12-dicarboxylic acid bis-4-vinylphenylamide monomer was written by Han, Xinxin;Wang, Chunlei;He, Lingfeng;Beesley, Thomas E.;Armstrong, Daniel W.. And the article was included in Analytical and Bioanalytical Chemistry in 2007.Category: chiral-phosphine-ligands This article mentions the following:

A new synthetic polymeric chiral stationary phase for liquid chromatog. was prepared via free-radical-initiated polymerization of trans-9,10-dihydro-9,10-ethanoanthracene-(11S,12S)-11,12-dicarboxylic acid bis-4-vinylphenylamide. The new polymeric chiral stationary phase (CSP) showed enantioselectivity for many chiral compounds in multiple mobile phases. High stability and sample capacities were observed on this polymeric chiral stationary phase. Mobile phase components and additives affected chiral separation greatly. This new synthetic chiral stationary phase is complementary to two other related com. available CSPs: the P-CAP and P-CAP-DP columns. Interactions between the chiral stationary phase and analytes that lead to retention and chiral recognition include hydrogen bonding, dipolar, and π-π interactions. Repulsive (steric) interactions also contribute to chiral recognition. 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. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Category: chiral-phosphine-ligands

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis