<i>anti</i>-Selective Catalytic Asymmetric Nitroaldol Reaction of α-Keto Esters: Intriguing Solvent Effect, Flow Reaction, and Synthesis of Active Pharmaceutical Ingredients
nitroalkanes and α-ketoesters in an anti-selective manner to afford synthetically versatile, densely functionalized, and optically active α-nitro tertiary alcohols. A chiral diamide ligand captured two distinct metal cations, giving rise to a catalytically competent solid-phase heterobimetallic catalyst by simple mixing via self-assembly. The advantage of the solid-phase asymmetric catalyst was realized
A series of N,N′-dialkylated derivatives of (1R,2R)-cyclohexane-1,2-diamine were synthesized, and a new approach to the one-pot preparation of this type of amine was demonstrated. The prepared diamines were used as organocatalysts for the two-stepsynthesis of α-hydroxy γ-keto esters from arenes, chlorooxoacetates, and ketones; they were also used as chiral ligands for Meervein–Ponndorf–Verley reductions
Enantioselective Nitroaldol Reaction of α-Keto Esters Catalyzed by a Copper(II)-Bisoxazolidine Complex
作者:Christian Wolf、Hanhui Xu
DOI:10.1055/s-0030-1259000
日期:2010.11
A wide range of aliphatic and aromatic α-keto esters has been transformed to α-hydroxy-β-nitro esters via the Cu(II)-bisoxazolidine-catalyzed Henry reaction. In the presence of 10 mol% of the chiral catalyst, nitroaldol products were obtained in up to 95% yield and 76% ee.
catalytic asymmetric Henry reaction of α-keto esters, 2-acylpyridines and 2-acylpyridine N-oxides. The corresponding β-nitro-α-hydroxy esters were obtained in good to excellent yields (up to 99%) with a high enantiomeric excess (ee) (up to 94%) with a catalyst loading of 1–2 mol%. The desired products of 2-acylpyridines and 2-acylpyridine N-oxides, which were simple methyl ketones, were obtained in medium