NHC as a Ligand in Heterobimetallic Catalysis: An Insight into a Catalytic Friedel-Crafts-like Reaction

The calculation of local reactivity descriptors, namely,localelectron density and the Fukui function index for nucleophilic attackat a center, established that in transition metal-tin heterobimetalliccomplexes, N-heterocyclic carbene (NHC) is a better ligand than itsalkene and phosphine analogues for the coupling of C-H andC-OH bonds. This insight was verified by synthesizing a newcomplex (NHC)(2)Pd(Br)(SnCl3), which turned outto be an excellent catalyst for the coupling of arene/heteroarenewith alcohol (0.5-1 mol %; 60 & DEG;C; >35 examples; highTOF).Results from kinetic and thermodynamic studies have been described.Correspondingly, a mechanism is proposed.