A Cyclometalated NHC Iridium Complex Bearing a Cationic (η -Cyclopentadienyl)(η -phenyl)iron Backbone*.

Nucleophilic substitution of [(η -cyclopentadienyl)(η -chlorobenzene)iron(II)] hexafluorophosphate with sodium imidazolate resulted in the formation of [(η -cyclopentadienyl)(η -phenyl)iron(II)]imidazole hexafluorophosphate. The corresponding dicationic imidazolium salt, which was obtained by treating this imidazole precursor with methyl iodide, underwent cyclometallation with bis[dichlorido(η -1,2,3,4,5-pentamethylcyclopentadienyl]iridium(III) in the presence of triethyl amine. The resulting bimetallic iridium(III) complex is the first example of an NHC complex bearing a cationic and cyclometallated [(η -cyclopentadienyl)(η -phenyl)iron(II)] substituent.

Accelerated Ru-Cu Trinuclear Cooperative C-H Bond Functionalization of Carbazoles: A Kinetic and Computational Investigation.

The mechanism of a trinuclear cooperative dehydrogenative C-N bond-forming reaction is investigated in this work, which avoids the use of chelate-assisting directing groups. Two new highly efficient Ru/Cu co-catalyzed systems were identified, allowing orders of magnitude greater TOFs than the previous state of the art. In-depth kinetic studies were performed in combination with advanced DFT calculations, which reveal a decisive rate-determining trinuclear Ru-Cu cooperative reductive elimination step (CRE).