Controlling the Selectivity of C−H Activation in Pyridinium Triazolylidene Iridium Complexes: Mechanistic Details and Influence of Remote Substituents

Kate F. Donnelly (1) , Ralte Lalrempuia (1) , Helge Müller-Bunz (1) , Eric Clot (2) , Martin Albrecht (1)

1 UCD - School of Chemistry and Chemical Biology
2 ICGM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier

Iridium complexes containing a triazolylidene ligand with an appended methylpyridinium site undergo either aromatic C(sp 2)−H bond activation or exocyclic C(sp 3)−H bond activation of the N-bound methyl group. The selectivity of these bond activations is controlled by the remote substituent R of the triazolylidene ligand. Iterative computational and synthetic experiments provide evidence for more facile C(sp 2)−H bond activation for a variety of remote substituents with R = Me, CH 2 C 6 F 5 , CH 2 CH 2 C 6 H 5. For triazolylidene ligands with a benzylic substituent, C(sp 2

Domaines: Chimie-Physique [physics.chem-ph]

Kate F. Donnelly, Ralte Lalrempuia, Helge Müller-Bunz, Eric Clot, Martin Albrecht. Controlling the Selectivity of C−H Activation in Pyridinium Triazolylidene Iridium Complexes: Mechanistic Details and Influence of Remote Substituents. Organometallics, 2015, 34, pp.858-869. ⟨10.1021/om501197g⟩. ⟨hal-01138729⟩