Month: February 2023

Catalyst-Directed Diastereoselectivity in Hydrogenative Couplings of Acetylene to α-Chiral Aldehydes: Formal Synthesis of All Eight L-Hexoses was written by Han, Soo Bong;Kong, Jong Rock;Krische, Michael J.. And the article was included in Organic Letters in 2008.Formula: C38H32O2P2 This article mentions the following:

Hydrogenative coupling of acetylene to α-chiral aldehydes using enantiomeric rhodium catalysts ligated by (S)-MeO-BIPHEP and (R)-MeO-BIPHEP delivers the diastereomeric products of carbonyl-(Z)-butadienylation with good to excellent levels of catalyst directed diastereofacial selectivity. Diastereomeric L-glyceraldehyde acetonide adducts were converted to the four isomeric enoates, e.g. I, representing a formal synthesis of all eight L-hexoses. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Formula: C38H32O2P2).

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

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Reversible nucleophilic addition can lower the observed enantioselectivity in palladium-catalyzed allylic amination reactions with a variety of chiral ligands was written by Caminiti, Nicholas S.;Goodstein, Madison B.;Leibler, Isabelle N.-M.;Holtzman, Bryan S.;Jia, Zitong B.;Martini, Michael L.;Nelson, Nathaniel C.;Bunt, Richard C.. And the article was included in Tetrahedron Letters in 2015.Application of 174810-09-4 This article mentions the following:

Palladium-catalyzed allylic amination is an important synthetic reaction that is also frequently used as a benchmark for the design and evaluation of new chiral ligands. The effect of reversible nucleophilic addition on the reaction of benzylamine with (E)-1,3-diphenylallyl Et carbonate (1) in CH₂Cl₂ was examined with 12 different chiral ligands across a range of scaffolding types. In 8 out of 12 cases the observed ee was significantly higher when DBU or Cs₂CO₃ was added to suppress the proton-driven reversibility. For chiral ligand screening with this test reaction, adding DBU or Cs₂CO₃ provides a better measure of the ligand’s inherent enantioselectivity. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4Application 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. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Application of 174810-09-4

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Practical Synthesis of MDM2 Antagonist RG7388. Part 2: Development of the Cu(I) Catalyzed [3 + 2] Asymmetric Cycloaddition Process for the Manufacture of Idasanutlin was written by Rimmler, Gosta;Alker, Andre;Bosco, Marcello;Diodone, Ralph;Fishlock, Dan;Hildbrand, Stefan;Kuhn, Bernd;Moessner, Christian;Peters, Carsten;Rege, Pankaj D.;Schantz, Markus. And the article was included in Organic Process Research & Development in 2016.COA of Formula: C38H32O2P2 This article mentions the following:

A concise catalytic asym. synthesis of idasanutlin was developed in which the key pyrrolidine core, containing four contiguous stereocenters, was constructed via a Ag/MeOBIPHEP promoted [3+2] cycloaddition reaction. Further development of the [3+2] cycloaddition reaction resulted in an improvement in diastereoselectivity and enantioselectivity by changing the catalyst system to Cu(I)/BINAP. While producing equivalent high quality API, the copper(I) catalyzed process not only increased the overall yield but also demonstrated benefit with respect to cycle times, waste streams and processability. The optimized copper(I) catalyzed process has been used to prepare more than 1500 kg of idasanutlin. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1COA of Formula: C38H32O2P2).

(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.COA of Formula: C38H32O2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective vinylation of aldehydes with chiral β-silylphosphorus ylides was written by Iio, Hideo;Fujii, Akio;Ishii, Masahiro;Tokoroyama, Takashi. And the article was included in Journal of the Chemical Society, Chemical Communications in 1991.Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine This article mentions the following:

Both enantiomers of diastereoisomeric [1-(dimethylaminoethyl)ferrocenyl]diphenyl(2-diphenylmethylsilylethylidene)phosphorane are prepared; their reaction with benzaldehyde and aliphatic aldehydes is found to give vinylation products with variable enantiomeric excess (up to 92%). 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. 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. Name: (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Synthesis of bornene-2,2′-diamino-1,1′-binaphthalene conjugates in palladium-catalysed aminocarbonylations was written by Mikle, Gabor;Boros, Borbala;Kollar, Laszlo. And the article was included in Tetrahedron: Asymmetry in 2016.Product Details of 77876-39-2 This article mentions the following:

Palladium-catalyzed aminocarbonylation of a terpenoic iodoalkene (2-iodobornene) model compound with both enantiomerically pure and racemic 2,2′-diamino-1,1′-binaphthalene (BINAM) as the N-nucleophile was carried out. All of the diastereoisomers of the monocarboxamide (N-bornenyl carboxamide) and dicarboxamide (N,N’-dinorbornenylcarboxamide) derivatives were synthesized. The diastereoselectivities of the aminocarbonylation were investigated in both cases: either racemic BINAM was used as the N-nucleophile in the aminocarbonylation of enantiomerically pure 2-iodobornene or racemic iodobornene was aminocarbonylated with enantiomerically pure BINAM with moderate diastereoselectivities. In this way, all possible diastereoisomers of binaphthalene-bornene conjugates were synthesized in moderate to high yields by asym. (diastereoselective) aminocarbonylation. 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. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. 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

Copper-catalyzed enantioselective allylic cross-coupling with alkylboranes was written by Hojoh, Kentaro;Shido, Yoshinori;Nagao, Kazunori;Mori, Seiji;Ohmiya, Hirohisa;Sawamura, Masaya. And the article was included in Tetrahedron in 2015.Name: (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl This article mentions the following:

Nonracemic alkenes such as (S)-3,4-(MeO)₂C₆H₃(CH₂)₃CH(CH₂CH₂Ph)CH:CH₂ and allylic silanes such as (S)-Me(CH₂)₇CH(SiMe₂Ph)CH:CH₂ were prepared by enantioselective S_N2′-type allylic substitution reactions of (Z)-allylic chlorides such as (Z)-PhCH₂CH₂CH:CHCH₂Cl and (Z)-PhMe₂SiCH:CHCH₂Cl with alkylboranes generated from terminal alkenes such as 1-allyl-3,4-dimethoxybenzene and 1-octene and the dimer of 9-borabicyclo[3.3.1]nonane in the presence of CuOTf•0.5PhMe and nonracemic biaryldiphosphine ligands using potassium methanolate or ethanolate in 1,4-dioxane/CH₂Cl₂ or THF/CH₂Cl₂ mixtures Using copper catalysts, enantioenriched chiral products containing tertiary or quaternary carbon stereogenic centers branched with functionalized sp³-alkyl groups were prepared; various functional groups (acetals, esters, silyl ethers, phthalimide) were tolerated. The wide availability of alkylboranes by hydroboration of alkenes is an attractive feature of these transformations. A reaction pathway involving addition and elimination of a neutral alkylcopper(I) species with the allyl chloride substrate is proposed. 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: 352655-61-9Name: (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl).

(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. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Name: (R)-(-)-2,2′-Bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-6,6′-dimethoxy-1,1′-biphenyl

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Iron-catalyzed olefin carbometalation was written by Nakamura, Masaharu;Hirai, Atsushi;Nakamura, Eiichi. And the article was included in Journal of the American Chemical Society in 2000.Reference of 55700-44-2 This article mentions the following:

Iron catalysts, involving a new (soft)phosphine/(hard)diamine ligand system for a iron/zinc bimetallic reagent, are effective for promotion of olefin enantioselective carbometalation. Thus, treatment of the cyclopropenone acetal I with RMgBr (R = Ph, allyl, Me, PhCH₂CH₂) or R₂Zn (R¹ = Et, pentyl) in THF containing FeCl₃ and subsequent hydrolysis with aqueous NH₄Cl gave the cyclopropanone acetals II (R = Ph, allyl, Me, PhCH₂CH₂, Et, pentyl; R¹ = H) in 66-96% yields. Similar treatment of I with PhMgBr and then with electrophiles, e.g. MeI, trans-cinnamyl chloride, or benzaldehyde, gave disubstituted cyclopropanes, e.g. II [R = Ph; R¹ = Me, PhCH(OH), (E)-PhCH:CHCH₂]. Enantioselective reaction of I with Et₂Zn in toluene containing FeCl₃, tetramethylethylenediamine, and (R)-2,2′-bis[bis(4-methylphenyl)phosphino]-1,1′-binaphthyl [(R)-p-tol-BINAP] for 6 days at -10° and one day at 0° followed by hydrolysis with aqueous NH₄Cl gave (R)-I (R¹ = Et; R² = H) in 64% yield and 90% ee. In the experiment, the researchers used many compounds, for example, (R)-N,N-Dimethyl-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethylamine (cas: 55700-44-2Reference of 55700-44-2).

(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. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Reference of 55700-44-2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Rhodium-Catalyzed Asymmetric Synthesis of Indanones: Development of a New “Axially Chiral” Bisphosphine Ligand was written by Shintani, Ryo;Yashio, Keiji;Nakamura, Tomoaki;Okamoto, Kazuhiro;Shimada, Toyoshi;Hayashi, Tamio. And the article was included in Journal of the American Chemical Society in 2006.Application of 133545-16-1 This article mentions the following:

A rhodium-catalyzed asym. isomerization of racemic α-arylpropargyl alcs. to β-chiral indanones has been developed. High enantioselectivity has been realized by the use of a newly developed axially chiral bisphosphine ligand. This ligand is unique in the sense that its axial chirality is fixed to a single configuration upon complexation to a transition metal due to other chiral axes existing within the same mol. 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. 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.Application of 133545-16-1

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Construction of quaternary stereogenic carbon centers through copper-catalyzed enantioselective allylic cross-coupling with alkylboranes was written by Hojoh, Kentaro;Shido, Yoshinori;Ohmiya, Hirohisa;Sawamura, Masaya. And the article was included in Angewandte Chemie, International Edition in 2014.Computed Properties of C74H104O6P2 This article mentions the following:

A combination of an in situ generated chiral Cu(I)/DTBM-MeO-BIPHEP [DTBM = 3,5-(Me₃C)₂C₆H₂-4-OMe] catalyst system and EtOK enabled the enantioselective S_N2′-type allylic cross-coupling between alkylborane reagents and γ,γ-disubstituted primary allyl chlorides with enantiocontrol at a useful level. The reaction generates a stereogenic quaternary carbon center having 3 sp³-alkyl groups and a vinyl group. This protocol allowed the use of terminal alkenes as nucleophile precursors, thus representing a formal reductive allylic cross-coupling of terminal alkenes. A reaction pathway involving addition/elimination of a neutral alkylcopper(I) species with the allyl chloride substrate is proposed. 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: 352655-61-9Computed Properties of C74H104O6P2).

(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. 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. Computed Properties of C74H104O6P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Development of a Second Generation Palladium Catalyst System for the Aminocarbonylation of Aryl Halides with CO and Ammonia was written by Wu, Xiao-Feng;Neumann, Helfried;Beller, Matthias. And the article was included in Chemistry – An Asian Journal in 2010.SDS of cas: 37002-48-5 This article mentions the following:

An improved and general Pd(OAc)₂/dppf-catalyzed aminocarbonylation of aryl and heteroaryl bromides and chlorides with CO and ammonia has been established. Primary amides are accessible under comparably mild conditions in good yield. 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: 37002-48-5SDS of cas: 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. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.SDS of cas: 37002-48-5

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis