1186531-03-2Relevant academic research and scientific papers
Mild oxidative addition of C-H bonds to a hydrido-bridged dinuclear complex of iridium(II) induced by the coordination of heteroatomic ligands
Takahashi, Yoshinori,Fujita, Ken-Ichi,Yamaguchi, Ryohei
, p. 4360 - 4368 (2009/02/08)
The oxidative addition of C-H bonds to a dinuclear complex of divalent iridium, [Cp*Ir(μ-H)]2 (1), has been investigated. Reactions of 1 with phosphorus compounds containing a phenyl ring (PR1R 2Ph) at ambient temperature gave novel five-membered diiridacyclic [(Cp*IrH)2(μ-H)(μ-R1R2PC 6H4)] [R1 = R2 = Me (2a); R 1 = Me, R2 = Ph (2b); R1 = R2 = Ph (2c); R1 = R2 = OEt (2d); and R1 = OEt, R 2 = Ph (2e)] complexes through ortho-C-H activation of the phenyl ring bound to the phosphorus atom. The reaction of 1 with tripropylphosphane gave a new four-membered diiridacyclic [(Cp*IrH)2(μ-H)(μ- Pr2PCHCH2CH3)] (3) complex in a similar manner. On the other hand, the reaction of 1 with triethyl phosphite gave a Cp*-metalated product, [Ir(H)(P(OEt)3)(μ,η5, η1-C5Me4CH2)-(μ-H)Ir(H) (Cp*)] (4), through C-H activation of a methyl group on one of the Cp* ligands. Furthermore, similar mild C-H activation reactions of 1 with sulfoxides have also been revealed. Thus, reactions of 1 with dimethyl sulfoxide and a couple of sulfoxides containing phenyl groups brought about the activation of the C-H bonds of a methyl group and a phenyl group to give [(Cp*IrH) 2(μ-H)(μ-MeS(=O)CH2)] (5) and [(Cp*IrH) 2(μ-H)(μ-RS(=O)C6H4)] [R = Me (6a) and R = Ph (6b)], respectively. The structures of 2a, 4, 5, and 6a have been confirmed by X-ray analysis. A plausible reaction pathway for these C-H activation reactions has been proposed. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
