Highly diastereoselective and enantioselective Michael addition of 5H-oxazol-4-ones to α,β-unsaturated ketones catalyzed by a new bifunctional organocatalyst with broad substrate scope and applicability
作者:Huicai Huang、Kailong Zhu、Wenbin Wu、Zhichao Jin、Jinxing Ye
DOI:10.1039/c1cc15928c
日期:——
A new thiourea-tertiary amine bifunctional catalyst derived from L-tert-leucine was developed and provides excellent stereocontrol in a novel and direct Michaeladdition of 5H-oxazol-4-ones to alpha,beta-unsaturated ketones with much broad substrate scope. The conjugate addition products with chiral vicinal quaternary and tertiary stereocenters can be easily transformed to structurally interesting
7-azaindol-3-ylacrylamides active as kinase inhibitors
申请人:NERVIANO MEDICAL SCIENCES S.r.l.
公开号:EP2070928A1
公开(公告)日:2009-06-17
Compounds represented by Formula (I)
wherein R1 and R2 are as defined in the specification, compositions thereof, and methods of use thereof.
由式(I)表示的化合物,其中R1和R2如规范中定义,以及它们的组合物和使用方法。
Enantioselective amination of nitroolefins under base-free and water-rich conditions using chiral bifunctional phase-transfer catalysts
作者:Junchao Zhu、Dongxiao Cui、Yuedan Li、Jingxu He、Weiping Chen、Pingan Wang
DOI:10.1039/c8ob00583d
日期:——
The direct enantioselective amination of nitroolefins has been performed with L-tert-leucine-derived squaramide-scaffold bifunctional phase-transfer catalysts under base-free and water-rich conditions with low catalyst loading (0.5–1 mol%) to provide 2-aminonitroalkanes in good yields (up to 96%) and enantioselectivities (up to 93% ee).
Multifunctional Catalysts in the Asymmetric Mannich Reaction of Malononitrile with <i>N</i>-Phosphinoylimines: Coactivation by Halogen Bonding versus Hydrogen Bonding
enantioselective Mannich reaction between malononitrile and diphenylphosphinoyl-protected aldimine affording products in high yields (up to 98%) and moderate to high enantiomeric purities (ee up to 89%). Typically, noncovalent catalysts rely on several weak interactions to activate the substrate, with one or two of these giving the most notable contribution to activation. In this instance, instead of the
the presence of an L-tert-leucine-derived urea–ammonium salt as phase-transfer catalyst, a highly enantioselective alkylation of 5H-oxazol-4-ones with various benzyl bromides and allylic bromides has been developed to furnish catalytic asymmetric synthesis of biologically important dialkylated α-hydroxy carboxylic acids with a broad scope. This is the first example of an L-amino acid-derived urea–ammonium