Day: February 22, 2023

Enantioselective Nickel-Catalyzed Si-C(sp²) Bond Activation and Migratory Insertion to Aldehydes: Reaction Scope and Mechanism was written by Wang, Qing;Zhong, Kang-Bao;Xu, Hao;Li, Shi-Nan;Zhu, Wei-Ke;Ye, Fei;Xu, Zheng;Lan, Yu;Xu, Li-Wen. And the article was included in ACS Catalysis in 2022.Electric Literature of C33H25OP This article mentions the following:

Transition-metal-catalyzed Si-C bond activation is one of the most important processes in both organosilicon chem. and homogeneous catalysis that is still rarely reported in the past decades, and the enantioselective versions based on transition-metal-catalyzed Si-C bond activation remain an ongoing challenge in asym. catalysis. Herein, the authors report a convenient and enantioselective Si-C bond cleavage-initiated [4 + 2] annulation of benzosilacyclobutenes with aldehydes, which provides an access to the direct synthesis of chiral six-membered oxasilacycles and their derivatives with high yields and enantioselectivities (up to 97% ee). The catalytic asym. reaction proceeds smoothly with the aid of a chiral TADDOL-derived phosphoramidite ligand and its chiral Ni complex with a suitable cavity. By switching the work-up of the reaction involved, the present strategy may be extended to subsequent downstream transformations of silyl ether-containing oxasilacycles to give chiral o-tolyl arylmethanols with high ees and quant. conversions. Exptl. results support that the strategy of Si-mediated organic synthesis controlled by Ni catalysis demonstrates a powerful potential for the facile synthesis of chiral alcs. and its drug-like derivatives Finally, mechanistic and computational studies of the Ni-catalyzed Si-C bond activation offer insights into the origin of the observed stereoselective outcome, and the d. functional theory calculation shows that the Ni-controlled Si-C(sp²) bond activation enables the controllable migratory insertion of benzaldehyde into the Ni-Si bond, which is recognized as the enantioselectivity-determining step. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Electric Literature of C33H25OP).

(S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Electric Literature of C33H25OP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Ming-Phos/Gold(I)-Catalyzed Stereodivergent Synthesis of Highly Substituted Furo[3,4-d][1,2]oxazines was written by Zhou, Lujia;Xu, Bing;Ji, Danting;Zhang, Zhan-Ming;Zhang, Junliang. And the article was included in Chinese Journal of Chemistry in 2020.Product Details of 1595319-95-1 This article mentions the following:

A gold(I)-catalyzed asym. intermol. tandem [3+3]-cyclization reaction of 2-(1-alkynyl)-2- alken-1-ones R¹CCC(=CHR³)(C(O)R²) (R¹ = Bu, Ph, 1-naphthyl, etc.; R² = Me, Ph; R³ = Ph, 4-methylphenyl, 4-methoxyphenyl, 4-chlorophenyl, 4-bromophenyl) with nitrones R⁴N(=O)=CHR⁵ (R⁴ = Ph, 4-methylphenyl, 4-methoxyphenyl, 3-chlorophenyl; R⁵ = Ph, styryl, furan-2-yl, etc.) has been developed by using Ming-Phos as a chiral ligand. This method enables access to the stereodivergent synthesis of highly substituted furo[3,4-d][1,2]oxazines I and II in excellent efficiency and stereoselectivity (up to 99% yield, 99% ee, >20 : 1 dr). In the experiment, the researchers used many compounds, for example, (R)-N-((S)-(2-(diphenylphosphaneyl)phenyl)(naphthalen-1-yl)methyl)-2-methylpropane-2-sulfinamide (cas: 1595319-95-1Product Details of 1595319-95-1).

(R)-N-((S)-(2-(diphenylphosphaneyl)phenyl)(naphthalen-1-yl)methyl)-2-methylpropane-2-sulfinamide (cas: 1595319-95-1) 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. Trivalent phosphorus compounds called phosphines have a tetrahedral electron-group geometry which makes them structurally analogous to amines.Product Details of 1595319-95-1

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

2-(Aminomethyl)pyridine-Phosphine Ruthenium(II) Complexes: Novel Highly Active Transfer Hydrogenation Catalysts was written by Baratta, Walter;Herdtweck, Eberhardt;Siega, Katia;Toniutti, Micaela;Rigo, Pierluigi. And the article was included in Organometallics in 2005.Formula: C29H30P2 This article mentions the following:

Trans,cis-RuCl₂(PPh₃)₂(ampy) (1) and trans-RuCl₂[Ph₂P(CH₂)₄PPh₂](ampy) (2) were prepared in high yield by reaction of RuCl₂(PPh₃)₃ and RuCl₂(PPh₃)[Ph₂P(CH₂)₄PPh₂] with 2-(aminomethyl)pyridine (ampy) at room temperature by PPh₃ displacement. Heating compound 1 in refluxing toluene leads to the isomer cis,cis-RuCl₂(PPh₃)₂(ampy) (3), which was proven to be a good precursor for the preparation of cis-RuCl₂(PP)(ampy) [PP = (S,S)-Chiraphos, 4; Ph₂P(CH₂)₃PPh₂, 5; (S,S)-Skewphos, 6; Ph₂P(CH₂)₄PPh₂, 7; (R,R)-Diop, 8] by displacement of two PPh₃ with the appropriate diphosphine. Cis-RuCl₂(PP)(ampy) [PP = (R,S)-Josiphos, 9; (R,S)-^tBu-Josiphos, 10] were synthesized from RuCl₂(PPh₃)₃ and PP followed by addition of ampy. The chiral complexes 4, 6, 8, 9, and 10 are formed stereoselectively, as inferred by NMR data in solution For the derivatives 7 and 9 the mol. structures were determined by x-ray measurements. The monohydride complex trans,cis-RuHCl(PPh₃)₂(ampy) (11) was prepared from RuHCl(PPh₃)₃ and ampy in heptane by PPh₃ substitution. Compound 11 reacts with Na isopropoxide in toluene, affording the dihydride derivative cis,trans-Ru(H)₂(PPh₃)₂(ampy) (12) via the alkoxide route. The intermediate species cis,cis-Ru(H)₂(PPh₃)₂(ampy) (A) was also characterized by NMR in solution All these complexes are highly efficient transfer hydrogenation catalysts. With cis-RuCl₂(PP)(ampy) a large number of ketones (dialkyl, diaryl, and alkyl-aryl) can be quant. reduced to alcs. in iso-PrOH and in the presence of NaOH (ketone/Ru/NaOH = 2000/1/40) with remarkably high TOF values (up to 400,000 h^-1 at 50% conversion). The derivatives containing chiral diphosphines afforded rapid (TOF > 10⁵ h^-1) and enantioselective (ee up to 94%) reduction of Me-aryl ketones using low loading of catalysts (0.05-0.01 mol %). In the absence of base the dihydride compound 12 catalyzes the transfer hydrogenation of acetophenone. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Formula: 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. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Formula: C29H30P2

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Enantioselective γ-lactam synthesis via palladium-catalyzed intramolecular asymmetric allylic alkylation was written by Bantreil, Xavier;Prestat, Guillaume;Madec, David;Fristrup, Peter;Poli, Giovanni. And the article was included in Synlett in 2009.Recommanded Product: (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) This article mentions the following:

A Pd(0)-catalyzed intramol. allylic alkylation in the presence of chiral atropisomeric bidentate ligands, e.g., (R)-3,5-t-Bu-MeOBIPHEP, takes place in up to 92:8 er in agreement with DFT calculations and provides easy access to enantioenriched disubstituted γ-lactams. E.g., 2.5 mol% [Pd(η³-C₃H₅)Cl]₂ in CH₂Cl₂ was added to 7.5 mol% (R)-BINAP at room temperature to which 1 equivalent of MeO₂CCH₂C(O)B(Bn)CH₂CH:CHCH₂OAc in CH₂Cl₂, BSA and KOAc were successively added to give N-benzyl-3-carbomethoxy-4-vinyl-γ-lactam in 88% yield. In the experiment, the researchers used many compounds, for example, (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine) (cas: 133545-16-1Recommanded Product: (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. The synthesis of novel trialkylphosphines can be quite difficult, thereby limiting the scope of their chiral variants. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Recommanded Product: (R)-(6,6′-Dimethoxy-[1,1′-biphenyl]-2,2′-diyl)bis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Evaluation of the Chiral DIANANE Backbone as Ligand for Organolithium Reagents was written by Praz, Jezabel;Guenee, Laure;Aziz, Sarwar;Berkessel, Albrecht;Alexakis, Alexandre. And the article was included in Advanced Synthesis & Catalysis in 2012.Electric Literature of C33H25OP This article mentions the following:

Novel endo,endo-2,5-diaminonorbonane-derived tertiary C₂-sym. diamines were synthesized via the one-pot reductive amination of enantiomerically pure norbornane-2,5-dione. These ligands were applied to various catalytic reactions such as asym. deprotonation, asym. bromine-lithium exchange, and enantioselective addition of aryl- and alkylithium reagents to aromatic aldimines. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Electric Literature of C33H25OP).

(S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9) belongs to chiral phosphine ligands. Thousands of arylphosphines have been used as chiral ligands for metal-catalyzed asymmetric reactions. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Electric Literature of C33H25OP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

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