Synthesis, Structure, and Reactivity of Iridium NHC Pincer Complexes

Iridium pincer complexes of the form ((CCCMes)-C-boolean AND-C-boolean AND)IrCl2 (1), ((CCCMes)-C-boolean AND-C-boolean AND)IrH4 (2), and ((CCCMes)-C-boolean AND-C-boolean AND)Ir(H)(2)L (L = PMe3 (3), pyridine (4)) have been prepared ((CCC)-C-boolean AND-C-boolean AND = [kappa(3)-1,3-(CH2NHCMes)(2)C6H3]; NHCMes = N-mesitylimidazol-2-ylidene). Complexes 1-4 are the first examples of iridium complexes with CCC pincer ligands containing methylene bridges. Complex 2 activates C-H bonds of arenes at room temperature, as demonstrated by isotope exchange reactions. Under analogous conditions, no reaction was observed with alkanes.