Insertion of nitrene and chalcogenolate groups into the Ir–C σ bond in a cyclometalated iridium(III) complex

Treatment of [Cp∗Ir(ppy)Cl] (Cp∗ = η5-C5Me5, ppyH = 2-(2-pyridyl)phenyl) with Ag(OTf) (OTf− = triflate) in MeOH and MeCN gave the solvento complexes [Cp∗Ir(ppy)(solv)][OTf] (solv = MeOH (1) and MeCN (2)). Complex 1 is capable of catalyzing oxidation and azirdination of styrene with PhIO and PhINTs (Ts = tosyl), respectively. Treatment of 2 with a stoichiometric amount of PhINTs resulted in the insertion of the NTs group into the Ir–C(ppy) bond and formation of [Cp∗Ir(η2-ppy-NTs)(MeCN)][OTf] (3). Treatment of 1 with R2E2 afforded [Cp∗Ir(ppy)(η1-R2E2)][OTf] (E = S (4), Se (5), Te (6)). Reactions of 4 and 5 with Ag(OTf) resulted in cleavage of the E–E bond and insertion of an ER group into the Ir–C(ppy) bond. The crystal structures of complexes 2–6 and [Cp∗Ir(η2-ppy-S-p-tol)(H2O)][OTf]2 have been determined.

Graphical abstract[Cp∗Ir(ppy)(H2O)][OTf] (Cp∗ = η5-C5Me5, ppy = 2-(2-pyridyl)phenyl, OTf− = triflate) can catalyze oxidation of styrene with PhIO. Treatment of [Cp∗Ir(ppy)(MeCN)][OTf] with PhINTs (Ts = tosyl) led to insertion of the nitrene group into the Ir–C(ppy) bond and formation of [Cp∗Ir(ppy)(η2-ppy-NTs)(MeCN)][OTf]. Reaction of [Cp∗Ir(ppy)(H2O)][OTf] with p-tol2S2 followed by treatment with Ag(OTf) afforded [Cp∗Ir(η2-ppy-S-p-tol)(H2O)][OTf]2.Figure optionsDownload full-size imageDownload as PowerPoint slide