Organocatalytic Asymmetric Snar Reactions Of 5H-oxazol-4-ones And Diaryloxazolidin-2,4-dione

Asymmetric organocatalysis has been attracting much interest of synthetic chemists due to the sustainable feature of using small organic molecules as catalysts.A range of efficient organocatalytic asymmetric methods have been established,affording diverse significant chiral compounds in a wariety of offields ranging from pharmaceuticals,agrochemicals to materials.This thesis outlines the development of organocatalytic asymmetric SNAr reactions of 5H-oxazol-4-ones and 3,5-diaryloxazolidin-2,4-diones to 2,4-dinitro-fluorobenzene,leading to a series of chiral a,a-diaryl and a-aryl-a-alkyl carboxylic acid derivatives featuring an a-tertiary hydroxyl moiety in high yields with good enantioselectivities.Newly developed dipeptide-based guanidiniums with multifunctional hydrogen-bonding donors as chiral phase-transfer catalysts were demonstrated to be viable to these transformations.