The Dynamic Kinetic Resolution of Azlactones with Thiol Nucleophiles Catalyzed by Arylated, Deoxygenated Cinchona Alkaloids
摘要:
A significant improvement of the available organocatalytic methods (in terms of product substrate scope and product enantiomeric excess) for the generation of enantioenriched alpha-amino acid thioesters via the dynamic kinetic resolution of azlactones is reported. C-9 arylated cinchona alkaloid catalysts have been found to be considerably superior to other bifunctional alkaloid catalysts as the promoters of this asymmetric process.
Group-Assisted Purification Chemistry for Asymmetric Mannich-type Reaction of Chiral <i>N</i>-Phosphonyl Imines with Azlactones Leading to Syntheses of α-Quaternary α,β-Diamino Acid Derivatives
作者:Haowei Zhang、Zhen Yang、Brian Nlong Zhao、Guigen Li
DOI:10.1021/acs.joc.7b02556
日期:2018.1.19
An asymmetric Mannich-type reaction between chiral N-phosphonyl imines and azlactones [oxazol-5(4H)-ones] has been established under convenient conditions at room temperature. The reaction was performed without using any bases, additives, or catalysts to achieve up to excellent chemical yields and diastereoselectivity for 32 examples. The α-quaternary syn-α,β-diamino acid products were purified simply
The Dynamic Kinetic Resolution of Azlactones with Thiol Nucleophiles Catalyzed by Arylated, Deoxygenated Cinchona Alkaloids
作者:Zaida Rodríguez-Docampo、Cormac Quigley、Sean Tallon、Stephen J. Connon
DOI:10.1021/jo202662d
日期:2012.3.2
A significant improvement of the available organocatalytic methods (in terms of product substrate scope and product enantiomeric excess) for the generation of enantioenriched alpha-amino acid thioesters via the dynamic kinetic resolution of azlactones is reported. C-9 arylated cinchona alkaloid catalysts have been found to be considerably superior to other bifunctional alkaloid catalysts as the promoters of this asymmetric process.