C-H bond activation in functionalized organic compounds with Cp*(PMe3)IrMe(OTf): generation, structural characterization and metal-based rearrangement of the acetone activation product Cp*(PMe3)Ir(η3-CH2C(OH)CH2)+OTf-

Article abstract of DOI:10.1016/0022-328X(95)05614-U

The iridium complex Cp^*(PMe3)Ir(Me)OTf (1) (Cp^* = η⁵-C5(CH3)5, OTf = OSO2CF3) reacts cleanly with acetone at room temperature.This reaction results in overall double C-H activation, generating the cationic η³-hydroxyallyl complexes Cp^*(PMe3)Ir(η³-CH2C(OH)CH2)⁺OTf^- (2).Complex 2 was characterized by X-ray diffraction and found to contain a hydrogen-bonded triflate anion.The ultimate product formed on reaction with acetone is strongly dependent upon the nature of the counterion present.Replacement of the triflate ion in 2 with other anions leads to the metallacyclobutanone Cp^*(PMe3)Ir(η²-CH2COCH2), the η¹-enolate Cp^*(PMe3)Ir(CH2COCH3)S(p-tolyl) and the free cation salt Cp^*(PMe3)Ir(η³-CH2C(OH)CH2)⁺ B(3,5-C6H3(CF3)2)4^-. Keywords: Iridium; C-H activation; Metallacycles