SEARCH

SEARCH BY CITATION

Keywords:

  • cyclopropanation;
  • diazo compounds;
  • homogeneous catalysis;
  • palladium

Abstract

The Pd0 complexes [(NHC)PdLn] (NHC=N-heterocyclic carbene ligand; L=styrene for n=2 or PR3 for n=1) efficiently catalyse olefin cyclopropanation by using ethyl diazoacetate (EDA) as the carbene source with activities that improve on previously described catalytic systems based on this metal. Mechanistic studies have shown that all of these catalyst precursors deliver the same catalytic species in solution, that is, [(IPr)Pd(sty)], a 14e unsaturated intermediate that further reacts with EDA to afford [(IPr)Pd([DOUBLE BOND]CHCO2Et)(sty)], from which the cyclopropane is formed.