1070237-57-8Relevant academic research and scientific papers
Highly enantioselective construction of CF3-bearing all-carbon quaternary stereocenters: Hiral spiro-fused bisoxazoline ligands with 1,1′-binaphthyl sidearm for asymmetric Michael-type Friedel-Crafts reaction
Bao, Robert Li-Yuan,Fu, Kang,Shi, Lei
supporting information, (2021/11/27)
A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared. The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields (up to 99%) and good to excellent enantioselectivies (up to > 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF3-β-disubstituted nitroalkene was favorable.
First Iridium-Catalyzed Highly Enantioselective Hydrogenation of β-Nitroacrylates
Li, Shengkun,Xiao, Taifeng,Li, Dangdang,Zhang, Xumu
, p. 3782 - 3785 (2015/08/18)
The first highly chemo- and enantioselective hydrogenation of β-nitroacrylates was accomplished with an iridium catalyst (Ir-4) with yields and enantioselectivities of up to 96% and 98% ee, respectively. The resulting α-chiral β-nitro propionates are attractive building blocks for the synthesis of chiral β2-amino acids, which are the core scaffolds of bioactive natural products, pharmaceuticals, and β-peptides.
Asymmetric friedel-crafts alkylation of α-substituted β-nitroacrylates: Access to β2,2-amino acids bearing indolic all-carbon quaternary stereocenters
Weng, Jian-Quan,Deng, Qiao-Man,Wu, Liang,Xu, Kai,Wu, Hao,Liu, Ren-Rong,Gao, Jian-Rong,Jia, Yi-Xia
supporting information, p. 776 - 779 (2014/03/21)
A highly enantioselective Friedel-Crafts alkylation reaction of indoles with acyclic α-substituted β-nitroacrylates is developed under the catalysis of Ni(ClO4)2-bisoxazoline complex at 1 mol % catalyst loading, affording chiral indolic β-nitroesters bearing all-carbon quaternary stereocenters in excellent yields and ees of up to 97%. Transformation of one of the products to β2,2-amino ester and tetrahydro-β-carboline through nitro reduction and sequential Pictet-Spengler cyclization was exemplified.
Chiral-at-metal octahedral iridium catalyst for the asymmetric construction of an all-carbon quaternary stereocenter
Chen, Liang-An,Tang, Xiaojuan,Xi, Jianwei,Xu, Weici,Gong, Lei,Meggers, Eric
supporting information, p. 14021 - 14025 (2014/01/06)
Metal-templated organocatalysis: The enantioselective formation of an all-carbon quaternary stereocenter is catalyzed by the ligand sphere of an inert bis-cyclometalated iridium complex (see picture). In this complex, the metal-centered chirality serves as the sole source for the effective asymmetric induction. Copyright
Readily available hydrogen bond catalysts for the asymmetric transfer hydrogenation of nitroolefins
Schneider, Jakob F.,Lauber, Markus B.,Muhr, Vanessa,Kratzer, Domenic,Paradies, Jan
supporting information; experimental part, p. 4323 - 4327 (2011/07/08)
This paper focuses on readily accessible thiourea hydrogen bond catalysts derived from amino acids, whose steric and electronic features are modulated by their degree of substitution at the carbinol carbon center. These catalysts were applied in the asymmetric transfer hydrogenation of nitroolefins furnishing the chiral products in up to 99% yield and 86% enantiomeric excess. The proposed catalyst's mode of action is supported by mechanistic investigations.
Organocatalytic asymmetric transferhydrogenation of β-nitroacrylates: Accessing β2-amino acids
Martin, Nolwenn J. A.,Cheng, Xu,List, Benjamin
supporting information; experimental part, p. 13862 - 13863 (2009/02/06)
We describe a highly efficient and enantioselective Hantzsch ester mediated conjugate reduction of β-nitroacrylates that is catalyzed by a Jacobsen thiourea catalyst as a key step in a new route to optically active β2-amino acids. Copyright
