1,2,4-Triazole-Based N-Heterocyclic Carb-ene Nickel Complexes - Synthesis and Catalytic Application
Résumé
Four nickel complexes bearing 1,2,4-triazole-based N-heterocyclic carbene backbones and a cyclopentadienyl ligand were prepd. from the corresponding 1,2,4-triazolium salts and nickelocene in THF (THF) under reflux. The obtained complexes were fully characterized, including by X-ray diffraction anal. They were then used as catalysts (5 mol-%) for the borylation of aryl bromide derivs. with bis(pinacolato)diboron in the presence of Cs2CO3 as the base in THF at 70 °C for 20 h to form the corresponding borylated products in moderate yields.