Day: February 23, 2023

Asymmetric Synthesis of C₂-Symmetric Axially Chiral Biaryls through Rhodium-Catalyzed and Alkyne-Controlled Diastereoselective Double [2+2+2]Cycloaddition was written by Mori, Ayaka;Araki, Tatsuya;Miyauchi, Yuta;Noguchi, Keiichi;Tanaka, Ken. And the article was included in European Journal of Organic Chemistry in 2013.Computed Properties of C29H30P2 This article mentions the following:

The asym. synthesis of C₂-sym. axially chiral biaryls was achieved by the cationic rhodium(I)/1,3-bis(diphenylphosphino)propane (dppp) complex catalyzed diastereoselective double [2+2+2]cycloaddition of (R)-3-butyn-2-ol-derived tetraynes with functionalized monoynes. Interestingly, the use of propiolate derivatives afforded biaryls possessing large dihedral angles, and in contrast, the use of propargyl alc. afforded biaryls possessing small dihedral angles. The title compounds thus formed included an isobenzofuran dimer (I) and related substances. Under optimized reaction conditions, the synthesis of the target compounds was achieved using bis(norbornadiene)rhodium(I) tetrafluoroborate and 1,1′-(1,3-propanediyl)bis[1,1-diphenylphosphine] as catalyst combination. The synthesis of the target compounds was achieved by a reaction of chiral 1,6-bis(2-butyn-1-yloxy)-2,4-hexadiyne, 1,6-bis(2-propyn-1-yloxy)-2,4-hexadiyne, 1,1′-[(2,4-hexadiyne-1,6-diyl)bis(oxy-1-propyne-3,1-diyl)]bis[benzene] with alkyne derivatives 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. 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.Computed Properties of C29H30P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium-Catalyzed Asymmetric Synthesis of Silicon-Stereogenic 5,10-Dihydrophenazasilines via Enantioselective 1,5-Palladium Migration was written by Sato, Yosuke;Takagi, Chihiro;Shintani, Ryo;Nozaki, Kyoko. And the article was included in Angewandte Chemie, International Edition in 2017.Synthetic Route of C42H56FeO2P2 This article mentions the following:

A palladium-catalyzed asym. synthesis of silicon-stereogenic 5,10-dihydrophenazasilines was developed that proceeds via an unprecedented enantioselective 1,5-palladium migration. High enantioselectivity was achieved by employing 4,4′-bis(trimethylsilyl) (R)-Binap as the chiral ligand, and a series of mechanistic investigations were carried out to probe the catalytic cycle of this process. 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: 360048-63-1Synthetic Route of 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. 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. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Synthetic Route of C42H56FeO2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Efficient P,N,N-type ligands for Ru(II)-catalyzed asymmetric cyclopropanations was written by Dai, Huicong;Hu, Xiangping;Chen, Huilin;Bai, Changmin;Zheng, Zhuo. And the article was included in Journal of Molecular Catalysis A: Chemical in 2004.Formula: C26H28FeNP This article mentions the following:

Novel chiral P,N,N-type ligands I (R = Me, R¹ = H, Me; R = Et, Ph, R¹ = H) derived from (R)-(S)-PPFNH₂-R and 2-pyridinecarboxaldehydes were employed in Ru(II)-catalyzed asym. cyclopropanation of styrene with Et diazoacetate. Up to 99% yield with 95% e.e. for cis-isomer and 90% e.e. for trans-isomer was obtained on Ru(II)/I (R = Me, R¹ = H). 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. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Asymmetric catalytic performance is determined not only by the metal center but also by the chiral ligand selected.Formula: C26H28FeNP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Dynamic kinetic asymmetric allylation of hydrazines and hydroxylamines was written by Mangion, Ian;Strotman, Neil;Drahl, Michael;Imbriglio, Jason;Guidry, Erin. And the article was included in Organic Letters in 2009.SDS of cas: 174810-09-4 This article mentions the following:

Hydrazines and hydroxylamines have been found to be excellent nucleophiles for the palladium-catalyzed dynamic asym. allylic amination of vinyl epoxide, with good yields and enantioselectivities of up to 97% ee. This method is applicable to acyclic and heterocyclic amines and was applied toward a five-step synthesis of (R)-piperazic acid. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4SDS of cas: 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. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.SDS of cas: 174810-09-4

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

A general enantioselective route to the chamigrene natural product family was written by White, David E.;Stewart, Ian C.;Seashore-Ludlow, Brinton A.;Grubbs, Robert H.;Stoltz, Brian M.. And the article was included in Tetrahedron in 2010.Recommanded Product: (R)-2-(2-(Bis(4-(trifluoromethyl)phenyl)phosphino)-5-(trifluoromethyl)phenyl)-4-(tert-butyl)-4,5-dihydrooxazole This article mentions the following:

Described in this report is an enantioselective route toward the chamigrene natural product family. The key disconnections in our synthetic approach include sequential enantioselective decarboxylative allylation and ring-closing olefin metathesis to form the all-carbon quaternary stereocenter and spirocyclic core present in all members of this class of compounds The generality of this strategy is demonstrated by the first total syntheses of elatol (I) and the proposed structure of laurencenone B, as well as the first enantioselective total syntheses of laurencenone C and α-chamigrene. A brief exploration of the substrate scope of the enantioselective decarboxylative allylation/ring-closing metathesis sequence with fully substituted vinyl chlorides is also presented. 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: 1006708-91-3Recommanded Product: (R)-2-(2-(Bis(4-(trifluoromethyl)phenyl)phosphino)-5-(trifluoromethyl)phenyl)-4-(tert-butyl)-4,5-dihydrooxazole).

(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. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Recommanded Product: (R)-2-(2-(Bis(4-(trifluoromethyl)phenyl)phosphino)-5-(trifluoromethyl)phenyl)-4-(tert-butyl)-4,5-dihydrooxazole

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Cyclic 1,2-Diketones as Core Building Blocks: A Strategy for the Total Synthesis of (-)-Terpestacin was written by Trost, Barry M.;Dong, Guangbin;Vance, Jennifer A.. And the article was included in Chemistry – A European Journal in 2010.Computed Properties of C52H44N2O2P2 This article mentions the following:

The sesterterpene (-)-terpestacin I is prepared using the stereoselective and enantioselective O-alkylation of diosphenols with allylic epoxides in the presence of a nonracemic diphosphine palladium catalyst and the subsequent stereoselective Claisen rearrangement to a nonracemic diosphenol with a quaternary stereocenter as the key steps. For example, reaction of 2-hydroxy-3-methyl-2-cyclopenten-1-one with 2-vinyl-2-methyloxirane (isoprene oxide) in the presence of tris(dibenzylideneacetone)dipalladium chloroform solvate and nonracemic Trost ligand II and tetrabutylammonium chloride followed by silylation yields the nonracemic tertiary allylic enol ether III (TIPS = triisopropylsilyl) in 93-95% yield and 88-96% ee; thermal rearrangement of III in chloroform (with adventitious HCl presumably as a catalyst) yields the substituted nonracemic diosphenol IV in 82-93% yield with 4-5:1 E:Z stereoselectivity. The palladium-catalyzed asym. allylic alkylation reaction of an allylic carbonate is used to generate the pendant hydroxypropyl moiety of I. Using this methodol., I is prepared in 20 steps (longest linear sequence) from com. available 2-hydroxy-3-methyl-2-cyclopenten-1-one. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4Computed Properties of C52H44N2O2P2).

N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4) belongs to chiral phosphine ligands. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Computed Properties of C52H44N2O2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium-Catalyzed Enantioselective C-H Arylation for the Synthesis of P-Stereogenic Compounds was written by Lin, Zi-Qi;Wang, Wei-Zhen;Yan, Shao-Bai;Duan, Wei-Liang. And the article was included in Angewandte Chemie, International Edition in 2015.Reference of 134484-36-9 This article mentions the following:

A palladium-catalyzed enantioselective C-H arylation of N-(o-bromoaryl)-diarylphosphinic amides is described for the synthesis of phosphorus compounds bearing a P-stereogenic center. The method provides good enantioselectivities and high yields. The products were readily transformed into P-chiral biphenyl monophosphine ligands. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Reference of 134484-36-9).

(S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Reference of 134484-36-9

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Asymmetric cross-coupling reactions: enantioselective synthesis of alkenyl sulfides was written by Cardellicchio, Cosimo;Fiandanese, Vito;Naso, Francesco. And the article was included in Gazzetta Chimica Italiana in 1991.COA of Formula: C26H28FeNP This article mentions the following:

An enantioselective synthesis of alkenyl sulfides by cross-coupling reactions between (E)- or (Z)-ArSCH:CHBr (I; Ar = Ph, 2-naphthyl, 2-pyridyl) and Grignard or organozinc reagents, using chiral complexes as catalysts, is described. The process is sensitive to several factors, e.g., the nature of the substrate, the organometallic reagent, the ligand, and the metal complex used as catalyst. Optical purities of up to 57% were achieved. The resulting unsaturated thioethers have been transformed into optically active 1-alkyl-2-phenylethenes or MeCHPhCO₂H. A new method for the synthesis of the starting (Z)-I is also reported. 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. 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.COA of Formula: C26H28FeNP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic Asymmetric C-H Arylation of (η⁶-Arene)Chromium Complexes: Facile Access to Planar-Chiral Phosphines was written by Batuecas, Maria;Luo, Junfei;Gergelitsova, Ivana;Kramer, Katrina;Whitaker, Daniel;Vitorica-Yrezabal, Inigo J.;Larrosa, Igor. And the article was included in ACS Catalysis in 2019.Formula: C33H25OP This article mentions the following:

A catalytic asym. direct C-H arylation of (η⁶-arene)chromium complexes to obtain planar-chiral compounds is reported. The use of the hemilabile ligand H₈-BINAP(O) is key to providing high enantioselectivity in this transformation. We show that this methodol. opens the door to the synthesis of a variety of planar-chiral chromium derivatives which can be easily transformed into planar chiral mono- or diphosphines. Mechanistic studies, including synthesis and characterization of Pd and Ag complexes and their detection in the reaction mixture, suggest a Pd-catalyzed/Ag-promoted catalytic system where Ag carries out the C-H activation step. 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. 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.Formula: C33H25OP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Highly Regioselective and Helix-Sense Selective Living Polymerization of Phenyl and Alkoxyallene Using Chiral Nickel(II) Catalysts was written by Zhou, Li;Li, Chong-Long;Gao, Run-Tan;Kang, Shu-Ming;Xu, Lei;Xu, Xun-Hui;Liu, Na;Wu, Zong-Quan. And the article was included in Macromolecules (Washington, DC, United States) in 2021.Recommanded Product: (R)-N-((S)-2-(Diphenylphosphanyl)-1-phenylethyl)-2-methylpropane-2-sulfinamide This article mentions the following:

Facile synthesis of high optically active helical polymers from achiral monomers still remains a great challenge. In this work, two chiral Ni(II) catalysts bearing chiral R- or S-2a ligands were facilely prepared which can efficiently initiate the living/controlled polymerization of allene monomers and afford well-defined polyallenes in high yields with controlled mol. masses (M_ns) and low mol. mass distributions (M_w/M_ns). The catalysts showed interesting regioselectivity on the cumulated double bonds of allene monomers, as the polymerizations were highly selective which occurred on 2,3-double bonds. Moreover, the polymerization of achiral allene monomers using chiral Ni(II) catalysts showed remarkable helix-sense selectivity. The yielded polyallenes exhibited high optical activity due to the formation of a predominant one-handed helix as revealed by CD, UV-vis, and direct at. force microscopy (AFM) observations as well. The predominant one-handed helicity of the generated polyallenes was solely determined by the chirality of the Ni(II) catalysts. In the experiment, the researchers used many compounds, for example, (R)-N-((S)-2-(Diphenylphosphanyl)-1-phenylethyl)-2-methylpropane-2-sulfinamide (cas: 1803239-44-2Recommanded Product: (R)-N-((S)-2-(Diphenylphosphanyl)-1-phenylethyl)-2-methylpropane-2-sulfinamide).

(R)-N-((S)-2-(Diphenylphosphanyl)-1-phenylethyl)-2-methylpropane-2-sulfinamide (cas: 1803239-44-2) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Effective chiral catalysts for nucleophilic phosphine catalysis are scarce, seriously limiting the development of asymmetric variants. Recommanded Product: (R)-N-((S)-2-(Diphenylphosphanyl)-1-phenylethyl)-2-methylpropane-2-sulfinamide

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis