Activation of ethylene and ammonia at iridium: C-H versus N-H oxidative addition

The ammine complexes cis-trans-[Ir(4-C5NF4)(H)(2)(NH3)(PiPr(3))(2)] (3) and cis-[Ir(4-C5NF4)(H){(E)-(MeO2C)C=CH(CO2Me)}(NH3)(2)(PiPr(3))] (5) are generated on reaction of cis-trans-[Ir(4-C5NF4)(H)(2)-(PiPr(3))(2)] (1) or of the vinyl compound trans-[Ir(4-C5NF4)(H){(E)-(MeO2C)C=CH(CO2Me)}(PiPr(3))(2)] (4) with NH3, respectively. Photolysis of 5 gives complex [Ir(4-C5NF4)(H){kappa(2)-(C,O)-(Z)-(MeO2C)C=CH(COOMe)}(NH3)(PiPr(3))] (6). Treatment of the ethylene compound trans-[Ir(4-C5NF4)-(C2H4)(PiPr(3))(2)] (2) with ammonia yields C-H activation products such as the hydrido vinyl species trans-[Ir(4-C5NF4)(H)(C2H3)(NH3)(PiPr(3))(2)] (7) and the cyclometallation products [Ir(4-C5NF4)(H)-(NH3){kappa(2)-(P,C)-CH2CH(CH3)PiPr(2)}(PiPr(3))] (8a, 8b). A subsequent reaction leads to the generation of the binuclear oxidative addition product of ammonia [Ir(4-C5NF4)(H)(mu-NH2)(NH3)(PiPr(3))](2) (9).