Facile Oxidative Addition of Organic Halides to Heteroleptic and Homoleptic Pd0–N‐Heterocyclic Carbene Complexes

Abstract

AbstractNovel heteroleptic Pd0 complexes with an N‐heterocyclic carbene (NHC) ligand [(Me3P)Pd(NHC)] (NHC = IPr, 1; SIPr, 2) were obtained from [Pd(CH2=CHPh)(PMe3)2] and an equivalent of NHC [NHC = 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr) or 1,3‐bis(2,6‐diisopropylphenyl)‐4,5‐dihydroimidazol‐2‐ylidene (SIPr)]. Further treatments of complexes 1 and 2 with an additional equimolar NHCafforded the corresponding bis(NHC)–Pd0 complexes [Pd(NHC)2] (NHC = IPr, 3; SIPr, 4). Complexes 1–4 readily reacted with dichloromethane or chloroform to give C–Cl oxidative addition products. In addition, the reactivity of complex 2 toward other organic halides such as bromobenzene, trans‐1,2‐dichloroethylene, and 5,5′‐dibromo‐2,2′‐bithiophene to produce the corresponding oxidative addition products was investigated. Finally, the ligand replacement of complex 1 with a chelating phosphane was examined.