Zn-Catalyzed Diastereo- and Enantioselective Cascade Reaction of 3-Isothiocyanato Oxindoles and 3-Nitroindoles: Stereocontrolled Syntheses of Polycyclic Spirooxindoles

Org Lett. 2015 Oct 16;17(20):5020-3. doi: 10.1021/acs.orglett.5b02489. Epub 2015 Sep 28.

Abstract

A catalytic asymmetric Michael/cyclization cascade reaction of 3-isothiocyanato oxindoles and 3-nitroindoles has been disclosed with a chiral Zn(OTf)2/diphenylamine-linked bis(oxazoline) complex as the catalyst. A range of enantioenriched polycyclic spirooxindole derivatives containing three contiguous stereocenters were efficiently constructed in quantitative yields with excellent diastereo- and enantioselectivities. Importantly, the metal catalytic strategy in this work is significantly superior to the previous organocatalytic method in the diastereo- and enantioselectivities for almost all of the examined cases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cyclization
  • Diphenylamine
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Isothiocyanates / chemistry*
  • Molecular Structure
  • Nitro Compounds / chemical synthesis*
  • Nitro Compounds / chemistry
  • Oxindoles
  • Polycyclic Compounds / chemical synthesis*
  • Polycyclic Compounds / chemistry
  • Spiro Compounds / chemical synthesis*
  • Spiro Compounds / chemistry
  • Stereoisomerism
  • Zinc / chemistry*

Substances

  • Indoles
  • Isothiocyanates
  • Nitro Compounds
  • Oxindoles
  • Polycyclic Compounds
  • Spiro Compounds
  • 2-oxindole
  • Diphenylamine
  • Zinc