Month: February 2023

Asymmetric Carroll rearrangement of allyl α-acetamido-β-keto carboxylates catalyzed by a chiral palladium complex was written by Kuwano, Ryoichi;Ishida, Naoki;Murakami, Masahiro. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2005.Safety of N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) This article mentions the following:

Asym. decarboxylative rearrangement (Carroll rearrangement) of allyl α-acetamido-β-keto carboxylates was catalyzed by a palladium complex modified with a chiral phosphine ligand, giving optically active γ,δ-unsaturated α-amino ketones with up to 90% ee. An efficient catalyst system thus used was tris(dibenzylideneacetone)dipalladium chloroform adduct and a Trost-type ligand, N,N‘-(1R,2R)-1,2-cyclohexanediylbis[2-(diphenylphosphino)-1-naphthalenecarboxamide]. Lower reactivities were observed with allyl esters, other than propenyl esters. In the experiment, the researchers used many compounds, for example, N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide) (cas: 174810-09-4Safety of 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. 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.Safety of N,N’-((1R,2R)-Cyclohexane-1,2-diyl)bis(2-(diphenylphosphino)-1-naphthamide)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Development of ruthenium catalysts for the enantioselective synthesis of P-stereogenic phosphines via nucleophilic phosphido intermediates was written by Chan, Vincent S.;Chiu, Melanie;Bergman, Robert G.;Toste, F. Dean. And the article was included in Journal of the American Chemical Society in 2009.Product Details of 133545-16-1 This article mentions the following:

Ruthenium chiral diphosphine complexes [L₂RuH][BPh₄] or [(L¹)(dmpe)RuH][BPh₄] [L, L¹ = chiral diphosphines, dmpe = 1,2-bis(dimethylphosphino)ethane] catalyze base-promoted low-temperature asym. alkylation of secondary phosphine PhMePH by benzyl halides, yielding chiral PhMe(ArCH₂)P (Ar = Ph, 4-ClC₆H₄, 4-MeC₆H₄, 4-MeOC₆H₄, 2-MeC₆H₄, 1-naphthyl, 2-pyridinyl, 2-furanyl) or diphosphines PhMePCH₂Ar¹CH₂PMePh (Ar¹ = 1,3-phenylene, 1,2-phenylene, 1,3-pyridinediyl) with up to 80% ee [L = 4-ⁱPr-2-(C₆H₄PPh₂-2)oxazoline (ⁱPr-PHOX) or L¹ = MeO-BiPHEP, SEGPHOS]. The optimized base for the reaction was found to be sodium tert-amylate, which prevents the occurrence of background non-catalytic alkylation by deprotonation of uncoordinated PhMePH. The reactions proceed through the intermediacy of nucleophilic phosphido species, which have low barriers to pyramidal inversion; this allows for a dynamic kinetic asym. alkylation. The initially discovered [((R)-ⁱPr-PHOX)₂Ru(H)][BPh₄] (6) catalyst was found to be effective in the reaction with benzylic chlorides; moreover, the alkylation displayed an unusual temperature dependence. However, the limited scope of alkylation of 6 motivated further studies which led to the development of two complementary chiral mixed ligand Ru(II) catalysts of type [L¹L²Ru(H)]⁺. These catalysts were derived from a combination of one chiral and one achiral ligand, where a synergistic interaction of the two ligands creates an effective asym. environment around the ruthenium center. The (R)-MeO-BiPHEP catalyst [((R)-MeO-BiPHEP)(dmpe)RuH][BPh₄] (10) was found to be effective for the asym. alkylation by benzyl chlorides, while the (R)-DIFLUORPHOS catalyst [[(R)-DIFLUORPHOS](dmpe)RuH][BPh₄] (11) was optimal for the nucleophilic substitution of less activated alkyl bromides; the scope of the resp. catalysts was also explored. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Product Details 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. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Chiral phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Product Details of 133545-16-1

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Rhodium-catalyzed addition of organoboronic acids to aldehydes was written by Sakai, Masaaki;Ueda, Masato;Miyaura, Norio. And the article was included in Angewandte Chemie, International Edition in 1998.SDS of cas: 134484-36-9 This article mentions the following:

The title reaction of RB(OH)₂ (R = Ph, p-anisyl, o-, p-tolyl, p-FC₆H₄, 2,4,6-Me₃C₆H₂, trans-BuCH:CH) with R¹CHO (R¹ = Ph, p-F₃CC₆H₄, p-NCC₆H₄, p-AcC₆H₄, p-BrC₆H₄, p-tolyl, p-anisyl, 2-furyl, 1-naphthyl, C₅H₁₁, C₆H₁₁) in the presence of Rh(acac)(CO)₂ in aqueous DME gave 31-97% 16 R¹RCHOH. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9SDS of cas: 134484-36-9).

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

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

From Acenaphthenes to (+)-Delavatine A: Visible-Light-Induced Ring Closure of Methyl (α-Naphthyl) Acrylates was written by Peez, Theodor;Luy, Jan-Niclas;Harms, Klaus;Tonner, Ralf;Koert, Ulrich. And the article was included in Chemistry – A European Journal in 2018.Quality Control of (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) This article mentions the following:

Disclosed herein is a visible light mediated cyclization of Me (α-naphthyl) acrylates and heteroaromatic analogs yielding substituted acenaphthenes and azaacenaphthenes, e.g., I. This highly functional-group-tolerant transformation was put to the test in an enantioselective formal synthesis of delavatine A (II). Mechanistic details were elucidated by DFT-calculations revealing an unusual intramol. H-transfer mediated by a primary amine. The generality of this transformation enables a novel synthetic strategy of five membered ring annulation at an advanced stage, allowing reliance upon naphthalene chem. up to the point of acenaphthene construction. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Quality Control of (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. Generally, the efficiency of nucleophilic phosphine catalysis often depends on the nature of the tertiary phosphine. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Quality Control of (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Investigations into the mechanism of the in situ formation of neutral dinuclear rhodium complexes was written by Moeller, Saskia;Kubis, Christoph;Drexler, Hans-Joachim;Alberico, Elisabetta;Heller, Detlef. And the article was included in Journal of Organometallic Chemistry in 2019.Electric Literature of C31H32O2P2 This article mentions the following:

The often applied in situ formation of neutral dinuclear rhodium precatalysts of the type [Rh(Diphosphine)(μ₂-Cl)]₂ with the ligands DPEPhos and DIOP has been mechanistically investigated by NMR spectroscopy. The structural characterization of reaction intermediates [Rh₂(μ₂-Diphosphine)(COD)₂(Cl)₂] and [Rh₂(Diphosphine)(COD)(μ₂-Cl)₂] was accomplished using x-ray crystallog. So a new and unexpected intermediate was found, which casts a new light on the mechanism of this ligand exchange. In addition, equilibrium could be found which can at least influence the formation of neutral dinuclear rhodium precatalysts. 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: 37002-48-5Electric Literature of 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. 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 phosphine catalysts: Nucleophilic phosphine catalysis often involves the formation of Lewis adducts, namely phosphonium (di)enolate zwitterions, as reaction intermediates.Electric Literature of C31H32O2P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

exo-Selective construction of spiro-[butyrolactone-pyrrolidine] via 1,3-dipolar cycloaddition of azomethine ylides with α-methylene-γ-butyrolactone catalyzed by Cu(I)/DTBM-BIPHEP was written by Li, Qing-Hua;Liu, Tang-Lin;Wei, Liang;Zhou, Xiang;Tao, Hai-Yan;Wang, Chun-Jiang. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2013.Recommanded Product: 352655-61-9 This article mentions the following:

An expedient access to optically active spiro-[butyrolactone-pyrrolidine] was successfully developed via an unprecedented Cu(I)-catalyzed exo-selective 1,3-DC of azomethine ylides with α-methylene-γ-butyrolactone, which exhibited high diastereoselectivity (>98 : 2), excellent enantioselectivity (96->99% ee) and a broad substrate scope under mild conditions [e.g., N-(4-chlorobenzylidene)glycine Me ester + α-methylene-γ-butyrolactone in presence of Cu(I)/DTBM-BIPHEP afforded I in >98:2 diastereoselectivity and almost perfect enantioselectivity]. 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: 352655-61-9Recommanded Product: 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. 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.Recommanded Product: 352655-61-9

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Ligand Tuning in Asymmetric Catalysis: Mono- and Bis-Phospholanes for a Prototypical Pd-Catalyzed Asymmetric Allylation Reaction was written by Yan, Yuan-Yong;RajanBabu, T. V.. And the article was included in Organic Letters in 2000.Name: (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) This article mentions the following:

Enantioselectivities and yields comparable to the best catalysts reported previously can be achieved in the addition of potassium di-Me malonate to diphenylallyl acetate by the use of Pd(0) complexes of bis-phospholanes prepared from D-mannitol. By appropriate changes in the C(2)-C(5) substituents, rare example of a useful monophosphine can also be prepared by a similar route. In both instances, chirality of C(3) and C(5) oxygen seems to play a crucial role in the asym. induction. 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: 37002-48-5Name: (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine)).

(((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.Name: (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective imine hydrogenation with Ir diphosphine catalysts: fighting deactivation was written by Blaser, Hans-Ulrich;Pugin, Benoit;Spindler, Felix;Togni, Antonio. And the article was included in Comptes Rendus Chimie in 2002.Quality Control of (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) This article mentions the following:

While Ir diphosphine complexes are very active catalysts for the enantioselective hydrogenation of imines with good to excellent enantioselectivity, their deactivation is often a serious problem, leading to low catalyst productivity. Our study describes attempts to stabilize Ir catalysts with DIOP, BDPP and BPPM ligands for the hydrogenation of different imines. The best results were obtained with complexes immobilized on silica gel and with bimetallic W-Ir and Mo-Ir complexes. In most cases, enantiomeric excesses as well as initial rates were only slightly affected while the stability of the catalysts was enhanced significantly. 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: 37002-48-5Quality Control of (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine)).

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

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective preparation of C₂-symmetrical ferrocenyl ligands for asymmetric catalysis was written by Schwink, Lothar;Knochel, Paul. And the article was included in Chemistry – A European Journal in 1998.Category: chiral-phosphine-ligands This article mentions the following:

Corey-Bakshi-Shibata (CBS) reduction of the 1,1′-diacylmetallocenes of Fe and Ru (e.g. 1,1′-(ClCH₂CH₂CH₂C(O))₂ferrocene) provides the C₂-sym. diols 4 (e.g. (R,R)-1,1′-(MeCH(OH))₂ferrocene) and 10, which proved to be useful starting materials for stereo-controlled ligand synthesis. Diols 4 and 10 can be easily converted to a wide range of diamines, diphosphines, and dithioacetates by nucleophilic substitution of the hydroxyl function with full retention of configuration. Also, the aminophosphines 30 (e.g. (αR,α’R)-2,2′-bis(α-(dimethylamino)(phenyl)methyl)-(S,S)-1,1′-bis(diphenylphosphino)ferrocene) and 31 (the Ru analog of the example for 30) become easily accessible. Compounds 30 and 31 were used as ligands complexed to Pd in enantioselective cross-coupling of racemic secondary Grignard reagents with vinyl bromides. A selectivity up to 93% ee could be reached for the 1st time in the preparation of (S)-(E)-1,3-diphenyl-1-butene, which was transformed into the enantiomerically pure chiral building block (2R,4R)-2,4-diphenyl-3-pentanol with a pseudoasym. center in a straightforward, three-step synthesis. 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: 174467-31-3Category: chiral-phosphine-ligands).

(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. 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

Immobilization of optically active rhodium-diphosphine complexes on porous silica via hydrogen bonding was written by Bianchini, Claudio;Barbaro, Pierluigi;Dal Santo, Vladimiro;Gobetto, Roberto;Meli, Andrea;Oberhauser, Werner;Psaro, Rinaldo;Vizza, Francesco. And the article was included in Advanced Synthesis & Catalysis in 2001.SDS of cas: 37002-48-5 This article mentions the following:

The authors describe, for the 1st time, the supported hydrogen-bonded (SHB) immobilization of various optically pure Rh(I) diphosphine complexes, including [((R)-(R)-BDPBzPSO₃)Rh(nbd)] (1), which contains the new chiral anionic ligand 4-((R)-Ph₂PCHMe)₂CHCH₂C₆H₄SO₃^–, [((+)-DIOP)-Rh(nbd)]OTf (2), and [((S)-BINAP)Rh(nbd)]OTf (3) (nbd = norbornadiene). A preliminary study of the potential of the resulting SHB catalysts in the enantioselective hydrogenation of prochiral olefins is also reported. 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. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Indeed, very little research on chiral tertiary phosphine-catalyzed asymmetric reactions occurred prior to the year 2000.SDS of cas: 37002-48-5

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis