Rediscovering copper-based catalysts for intramolecular carbon–hydrogen bond functionalization by carbene insertion

Abstract

A series of Tp^xCu complexes (Tp^x = hydrotrispyrazolylborate ligand) have been tested as catalysts for the decomposition of several diazoacetates and N,N-disubstituted diazoacetamides and the subsequent formation of lactones and lactams, respectively. The complexes containing the ligands Tp^Br3 or Tp^Ms have provided activities and selectivities for these transformations comparable with or, in some cases, better than the well-known rhodium catalyst Rh₂(OAc)₄.