Month: February 2023

The total synthesis of (-)-strempeliopine via palladium-catalyzed decarboxylative asymmetric allylic alkylation was written by An, Yi;Wu, Mengjuan;Li, Weijian;Li, Yaling;Wang, Zhenzhen;Xue, Yansong;Tang, Pei;Chen, Fener. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2022.Electric Literature of C28H23F9NOP This article mentions the following:

In the work reported herein, the concise and enantioselective total synthesis of the Schizozygine alkaloid (-)-strempeliopine was developed. This synthetic strategy featured the palladium-catalyzed decarboxylative asym. allylic alkylation of N-benzoyl lactam to set up the absolute configuration at the C20 position, a highly diastereoselective one-pot Bischler-Napieralski/lactamization and iminium reduction sequence for the construction of the pentacyclic core structure, and the late-stage dearomative addition of indole, leading to the otherwise difficult-to-achieve hexacyclic indoline framework with complete control of four neighboring stereocenters. 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: 1006708-91-3Electric Literature of C28H23F9NOP).

(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. 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. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Electric Literature of C28H23F9NOP

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Catalytic asymmetric cyclocarbonylation of o-isopropenylphenols: Enantioselective synthesis of six-membered ring lactones was written by Dong, Chune;Alper, Howard. And the article was included in Journal of Organic Chemistry in 2004.Name: (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine) This article mentions the following:

Cyclocarbonylation of o-isopropenylphenols with CO and H₂, using Pd(OAc)₂ and (+)-DIOP as the chiral catalyst, in CH₂Cl₂ afforded 3,4-dihydro-4-methylcoumarins, e.g., I, in good yields and enantiomeric excess. The stereoselectivity was influenced by the structure of the chiral phosphine ligands and substrates, as well as by the reaction conditions. 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. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Name: (((4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-diyl)bis(methylene))bis(diphenylphosphine)

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

²H-quadrupolar coupling-based analysis of stereochemical and regiochemical memory in the Pd-catalyzed allylic alkylation of iso-cinnamyl type substrates employing the chiral monophosphine ligands “MOP” and “MAP” was written by Gouriou, Laure;Lloyd-Jones, Guy C.;Vyskocil, Stepan;Kocovsky, Pavel. And the article was included in Journal of Organometallic Chemistry in 2003.Safety of (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine This article mentions the following:

The reaction of isocinnamyl acetate with NaC(Me)(CO₂Me)₂, catalyzed by Pd-MOP (MOP = 2-methoxy-2′-diphenylphosphino-1,1′-binaphthalene) is known to proceed with a regiochem. memory effect that results in the predominant generation of the branched alkylation product. The analogous reaction employing MAP as ligand (MAP = 2-N,N-dimethylamino-2′-diphenylphosphino-1,1′-binaphthalene) proceeds with normal regioselectivity to generate predominantly the linear isomer of product. A ²H-NMR based anal., employing quadrupolar coupling in a chiral liquid crystal matrix, has been developed to facilitate the simultaneous study of the regiochem. and stereochem. outcome of the reaction of both enantiomers of iso-cinnamyl ester substrates in ²H-labeled but racemic samples. The anal. allows the comparison of relative rates of two competing isomerization processes occurring in the π-allyl intermediates in the Pd-catalyzed reaction, one of which facilitates asym. induction, the other resulting in loss of regiochem. memory. It is demonstrated that the two processes are partially coupled and that this then limits the attainment of high global enantiomeric excess in the branched product to reactions that proceed with low regiochem. retention. A key factor for the observation of high regiochem. memory is found to be the nucleophilicity of the malonate anion and the electrophilicity of the Pd-π-allyl intermediate with reduction in the reactivity of either partner resulting in the onset of substantial loss of memory. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Safety of (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine).

(S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9) belongs to chiral phosphine ligands. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Safety of (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Palladium-Catalyzed Asymmetric Intramolecular Reductive Heck Desymmetrization of Cyclopentenes: Access to Chiral Bicyclo[3.2.1]octanes was written by Yuan, Zhenbo;Feng, Ziwen;Zeng, Yuye;Zhao, Xiaobin;Lin, Aijun;Yao, Hequan. And the article was included in Angewandte Chemie, International Edition in 2019.Safety of (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine This article mentions the following:

A palladium-catalyzed asym. reductive Heck reaction of unactivated aliphatic alkenes, with eliminable β-hydrogen atoms, was realized for the first time. A series of optically active bicyclo[3.2.1]octanes bearing chiral quaternary and tertiary carbon stereocenters were obtained in good yields with excellent enantioselectivities, exhibited good functional-group tolerance and scalability. Moreover, deuterated optically active bicyclo[3.2.1]octanes were also obtained in high efficiency. In the experiment, the researchers used many compounds, for example, (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine (cas: 134484-36-9Safety of (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine).

(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. Most of these phosphines are acyclic, usually possess low nucleophilic activity, and generally display poor enantioselectivities for phosphine organocatalysis. Safety of (S)-(2′-Methoxy-[1,1′-binaphthalen]-2-yl)diphenylphosphine

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis

Highly Chemoselective Metal-Free Reduction of Phosphine Oxides to Phosphines was written by Li, Yuehui;Lu, Liang-Qiu;Das, Shoubhik;Pisiewicz, Sabine;Junge, Kathrin;Beller, Matthias. And the article was included in Journal of the American Chemical Society in 2012.Reference of 37002-48-5 This article mentions the following:

Unprecedented chemoselective reductions of phosphine oxides to phosphines proceed smoothly in the presence of catalytic amounts of specific Bronsted acids. By utilizing inexpensive silanes, e.g., PMHS or (EtO)₂MeSiH, other reducible functional groups such as ketones, aldehydes, olefins, nitriles, and esters are well-tolerated under optimized conditions. 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: 37002-48-5Reference of 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. At present, the synthesis of new chiral phosphines designed specifically for nucleophilic organocatalysis remains a significant challenge. Over the last decade, however, and especially since 2005, considerable progress has been made in asymmetric phosphine catalysis.Reference of 37002-48-5

Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis