Sonogashira cross-coupling reaction catalysed by mixed NHC-Pd-PPh3 complexes under copper free conditions

Abstract

Mixed NHC-Pd-PPh3 complexes with a methoxyethyl-substituted N-heterocyclic carbene ( NHC) were synthesised and characterised by NMR, HRMS, elemental analysis and X-ray crystallography for complex 3b. These complexes were applied to Sonogashira cross-coupling reactions between aryl bromides and phenylacetylene in DMF at 80 degrees C. All palladium complexes were stable and showed high catalytic activity in Sonogashira reactions at low catalyst loading and ambient reaction conditions. (c) 2018 Elsevier B.V. All rights reserved.