957770-66-0Relevant academic research and scientific papers
Catalytic atroposelective dynamic kinetic resolutions and kinetic resolutions towards 3-arylquinolinesviaSNAr
Cardenas, Mariel M.,Saputra, Mirza A.,Gordon, Deane A.,Sanchez, Andrea N.,Yamamoto, Nobuyuki,Gustafson, Jeffrey L.
supporting information, p. 10087 - 10090 (2021/10/06)
Herein we report the catalytic atroposelective syntheses of pharmaceutically relevant 3-arylquinolinesviathe nucleophilic aromatic substitution (SNAr) of thiophenols into 3-aryl-2-fluoroquinolines mediated by catalytic amounts of Cinchona alkaloid-derived ureas. These reactions displayed a spectrum of dynamic kinetic resolution (DKR) and kinetic resolution (KR) characters depending upon the stereochemical stability of the starting material. Low barrier substrates proceededviaDKR while higher barrier substrates proceededviaKR. On the other hand, substrates with intermediate stabilities displayed hallmarks of both DKR and KR. Finally, we also show that we can functionalize the atropisomerically enriched quinolines into pharmaceutically privileged scaffolds with minimal observed racemization.
Combined Computational and Experimental Studies on the Asymmetric Michael Addition of α-Aminomaleimides to β-Nitrostyrenes Using an Organocatalyst Derived from Cinchona Alkaloid
Sakai, Naoki,Kawashima, Kyohei,Kajitani, Masashi,Mori, Seiji,Oriyama, Takeshi
supporting information, p. 5714 - 5718 (2021/08/01)
Maleimides are often used as electrophiles in conventional reactions; however, their application as nucleophiles is limited to only a few reactions, and reactions utilizing α-aminomaleimides as asymmetric Michael donors have not been reported to date. Thus, in this work, asymmetric Michael addition of α-aminomaleimides as Michael donors to β-nitrostyrenes was conducted for the first time using an organocatalyst derived from a Cinchona alkaloid. Density functional theory investigations were crucial to improve the enantioselectivity of the adduct.
Catalytic Asymmetric Synthesis of Quaternary Barbituric Acids
Del Pozo, Sandra,Vera, Silvia,Oiarbide, Mikel,Palomo, Claudio
, p. 15308 - 15311 (2017/11/06)
The catalytic asymmetric α-functionalization of prochiral barbituric acids, a subtype of pseudosymmetric 1,3-diamides, to yield the corresponding 5,5-disubstituted (quaternary) derivatives remains essentially unsolved. In this study 2-alkylthio-4,6-dioxopirimidines are designed as key 1,3-diamide surrogates that perform exceedingly in amine-squaramide catalyzed C-C bond forming reactions with vinyl ketones or Morita-Baylis-Hillmann-type allyl bromides as electrophiles. Mild acid hydrolysis of adducts affords barbituric acid derivatives with an in-ring quaternary carbon in unprecedented enantioselectivity, offering valuable materials for biological evaluations.
Induction of Axial Chirality in 8-Arylquinolines through Halogenation Reactions Using Bifunctional Organocatalysts
Miyaji, Ryota,Asano, Keisuke,Matsubara, Seijiro
supporting information, p. 9996 - 10000 (2017/08/01)
The enantioselective syntheses of axially chiral heterobiaryls were accomplished through the aromatic electrophilic halogenation of 3-(quinolin-8-yl)phenols with bifunctional organocatalysts that control the molecular conformations during successive halogenations. Axially chiral quinoline derivatives, which have rarely been synthesized in an enantioselective catalytic manner, were afforded in moderate-to-good enantioselectivities through bromination, and an analogous protocol also enabled enantioselective iodination. In addition, this catalytic reaction, which allows enantioselective control through the use of mono-ortho-substituted substrates, allowed the asymmetric synthesis of 8-arylquinoline derivatives bearing two different halogen groups in high enantioselectivities.
Stereoselective glycosylation of 2-nitrogalactals catalyzed by a bifunctional organocatalyst
Medina, Sandra,Harper, Matthew J.,Balmond, Edward I.,Miranda, Silvia,Crisenza, Giacomo E. M.,Coe, Diane M.,McGarrigle, Eoghan M.,Galan, M. Carmen
supporting information, p. 4222 - 4225 (2016/09/09)
The use of a bifunctional cinchona/thiourea organocatalyst for the direct and α-stereoselective glycosylation of 2-nitrogalactals is demonstrated for the first time. The conditions are mild, practical, and applicable to a wide range of glycoside acceptors with products being isolated in good to excellent yields. The method is exemplified in the synthesis of mucin type Core 6 and 7 glycopeptides.
Enantioselective Alkylative Kinetic Resolution of 2-Oxindole-Derived Enolates Promoted by Bifunctional Phase Transfer Catalysts
Sorrentino, Emiliano,Connon, Stephen J.
, p. 5204 - 5207 (2016/11/02)
The first strategy for bringing about highly enantioselective alkylative enolate kinetic resolutions using a simple phase-transfer protocol via SN2 chemistry has been developed. In the presence of a new squaramide-based quaternized cinchona alkaloid-derived catalyst and aqueous base, benzyl, allyl, and propargyl halides react with racemic substituted oxindoles to generate densely functionalized products with the two contiguous stereocenters, one of which is an all-carbon quaternary.
Asymmetric indoline synthesis via intramolecular aza-Michael addition mediated by bifunctional organocatalysts
Miyaji, Ryota,Asano, Keisuke,Matsubara, Seijiro
supporting information, p. 3658 - 3661 (2013/08/23)
A novel method for the asymmetric synthesis of 2-substituted indolines, employing bifunctional amino(thio)urea catalysts, was developed. The reaction proceeded via an intramolecular aza-Michael addition mediated by activation through hydrogen bonding. The
