951-85-9Relevant academic research and scientific papers
Enantioselective α-Arylation of Ketones via a Novel Cu(I)-Bis(phosphine) Dioxide Catalytic System
Escudero-Casao, Margarita,Licini, Giulia,Orlandi, Manuel
supporting information, p. 3289 - 3294 (2021/04/07)
A novel catalytic system based on copper(I) and chiral bis(phosphine) dioxides is described. This allows the arylation of silyl enol ethers to access enolizable α-arylated ketones in good yields and enantiomeric excess up to 95%. Noncyclic ketones are amenable substrates with this method, which complements other approaches based on palladium catalysis. Optimization of the ligand structure is accomplished via rational design driven by correlation analysis. Preliminary mechanistic hypotheses are also evaluated in order to identify the role of chiral bis(phosphine) dioxides.
Enantioselective decarboxylative protonation and deuteration of β-ketocarboxylic acids
Mizutani, Haruna,Kawanishi, Ryouta,Shibatomi, Kazutaka
supporting information, p. 6676 - 6679 (2021/07/12)
Enantioselective decarboxylative protonation of tetralone-derived β-ketocarboxylic acids was achieved with up to 89% enantiomeric excess (ee)-in the presence of a chiral primary amine catalyst. Furthermore, this method was applied to enantioselective deuteration to afford the corresponding α-deuterioketones with up to 88% ee.
Catalytic Reductive Cross Coupling and Enantioselective Protonation of Olefins to Construct Remote Stereocenters for Azaarenes
Kong, Manman,Tan, Yaqi,Zhao, Xiaowei,Qiao, Baokun,Tan, Choon-Hong,Cao, Shanshan,Jiang, Zhiyong
supporting information, p. 4024 - 4031 (2021/04/07)
A novel enantioselective protonation protocol that is triggered by reductive cross coupling of olefins is reported. When under cooperative photoredox and chiral hydrogen-bonding catalytic conditions and using a terminal reductant, various α-branched vinyl
Combined Photoredox and Carbene Catalysis for the Synthesis of Ketones from Carboxylic Acids
Betori, Rick C.,Davies, Anna V.,Fitzpatrick, Keegan P.,Scheidt, Karl A.
supporting information, p. 9143 - 9148 (2020/03/30)
As a key element in the construction of complex organic scaffolds, the formation of C?C bonds remains a challenge in the field of synthetic organic chemistry. Recent advancements in single-electron chemistry have enabled new methods for the formation of various C?C bonds. Disclosed herein is the development of a novel single-electron reduction of acyl azoliums for the formation of ketones from carboxylic acids. Facile construction of the acyl azolium in situ followed by a radical–radical coupling was made possible merging N-heterocyclic carbene (NHC) and photoredox catalysis. The utility of this protocol in synthesis was showcased in the late-stage functionalization of a variety of pharmaceutical compounds. Preliminary investigations using chiral NHCs demonstrate that enantioselectivity can be achieved, showcasing the advantages of this protocol over alternative methodologies.
Mechanistic Investigation of Enantioconvergent Kumada Reactions of Racemic α-Bromoketones Catalyzed by a Nickel/Bis(oxazoline) Complex
Yin, Haolin,Fu, Gregory C.
supporting information, p. 15433 - 15440 (2019/10/22)
In recent years, a wide array of methods for achieving nickel-catalyzed substitution reactions of alkyl electrophiles by organometallic nucleophiles, including enantioconvergent processes, have been described; however, experiment-focused mechanistic studies of such couplings have been comparatively scarce. The most detailed mechanistic investigations to date have examined catalysts that bear tridentate ligands and, with one exception, processes that are not enantioselective; studies of catalysts based on bidentate ligands could be anticipated to be more challenging, due to difficulty in isolating proposed intermediates as a result of instability arising from coordinative unsaturation. In this investigation, we explore the mechanism of enantioconvergent Kumada reactions of racemic α-bromoketones catalyzed by a nickel complex that bears a bidentate chiral bis(oxazoline) ligand. Utilizing an array of mechanistic tools (including isolation and reactivity studies of three of the four proposed nickel-containing intermediates, as well as interrogation via EPR spectroscopy, UV-vis spectroscopy, radical probes, and DFT calculations), we provide support for a pathway in which carbon-carbon bond formation proceeds via a radical-chain process wherein a nickel(I) complex serves as the chain-carrying radical and an organonickel(II) complex is the predominant resting state of the catalyst. Computations indicate that the coupling of this organonickel(II) complex with an organic radical is the stereochemistry-determining step of the reaction.
SYNTHESIZING METHOD OF α-TERTIARY ARYL KETONE
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Paragraph 0081; 0082; 0084; 0085; 0086, (2017/08/02)
The present invention relates to a synthesizing method of alpha-tertiary aryl ketone. The synthesizing method of alpha-tertiary aryl ketone synthesizes alpha-tertiary aryl ketone by making aldehyde react with aryldiazoalkanes under a chiral boron Lewis ac
Catalytic Asymmetric Formal Insertion of Aryldiazoalkanes into the C-H Bond of Aldehydes: Synthesis of Enantioenriched Acyclic α-Tertiary Aryl Ketones
Kang, Byung Chul,Nam, Dong Guk,Hwang, Geum-Sook,Ryu, Do Hyun
supporting information, p. 4810 - 4813 (2015/10/12)
A novel, catalytic enantioselective route to synthesize a variety of α-tertiary aryl ketones via a boron Lewis acid promoted formal insertion of aryldiazoalkane into the C-H bond of both aromatic and aliphatic aldehydes is described. In the presence of ch
Decoding stereocontrol during the photooxygenation of oxazolidinone- functionalized enecarbamates
Solomon, Marissa R.,Sivaguru,Jockusch, Steffen,Adam, Waldemar,Turro, Nicholas J.
supporting information; experimental part, p. 2142 - 2145 (2010/07/16)
Figure presented Systematically designed oxazolidinone-derived enecarbamates reveal that solvent and temperature effects on the stereoselectivity during photooxygenation are likely due to the conformational flexibility of the chiral phenethyl side chain (entropy factors); the extent of enantiomeric excess in the photoproduct is dictated by the alkene geometry.
Isolation and syn elimination of a peterson adduct to obtain optically pure product in the diastereoselective synthesis of oxazolidinone-functionalized enecarbamates
Solomon, Marissa R.,Saito, Hideaki,Sivaguru,Jockusch, Steffen,Inoue, Yoshihisa,Adam, Waldemar,Turro, Nicholas J.
scheme or table, p. 362 - 366 (2010/04/23)
The Peterson reaction of (4R)-N-(trimethylsilyl)methyl-4-alkyloxazolidin-2- one gives (E/Z)-(4R)-N-(2', 3'- diphenylbut-1'-enyl)-4-alkyloxazolidin-2-ones (enecarbamates) with increasing (Z)-selectivity and moderate-to-high diastereoselectivity in the indi
