C-H activation of 2,4,6-triphenylphosphinine: unprecedented formation of cyclometalated [(P[caret]C)Ir(iii)] and [(P[caret]C)Rh(iii)] complexes

An unprecedented C-H activation of 2,4,6-triphenylphosphinine by Ir(iii) and Rh(iii) has been observed. Time-dependent 31P{1H} NMR spectroscopy gave insight into the cyclometalation reaction and the corresponding coordination compounds were characterized by means of X-ray crystallography. In contrast, 2,4,6-triphenylpyridine does not show any ortho-metalation, demonstrating a remarkable difference in reactivity between these two structurally related aromatic heterocycles.