Functionalization of 1,3,4-Oxadiazoles and 1,2,4-Triazoles via Selective Zincation or Magnesiation Using 2,2,6,6-Tetramethylpiperidyl Bases
Kuno Schwärzer, Carl Phillip Tüllmann, Simon Graßl, Bartosz Górski, Cara E. Brocklehurst, Paul Knochel
Abstract
We report the metalation of the 1,3,4-oxadiazole and 1,2,4-triazole scaffolds via regioselective zincation or magnesiation using the TMP bases (TMP = 2,2,6,6-tetramethylpiperidyl) TMP2Zn·2LiCl, TMP2Zn·2MgCl2·2LiCl, TMPMgCl·LiCl, and TMPZnCl·LiCl under mild conditions in THF. Subsequent trapping with various electrophiles including hydroxylamino benzoates gives access to functionalized heterocycles while tolerating many functional groups.
Topics & Concepts
ChemistryElectrophileRegioselectivityMetalationSurface modificationCombinatorial chemistryBenzoatesOrganic chemistryCatalysisPhysical chemistryCoordination Chemistry and OrganometallicsCyclopropane Reaction MechanismsSynthesis and Reactivity of Heterocycles