κ3(P,C,C)‑Allylphosphane Iridium(III) and Rhodium(III) Complexes: Preparation and Reactivity toward Nucleophilic Reagents

The first allylphosphane iridium complexes [IrCl2(η5-C5Me5)­{κ­(P)-R2PCH2CHCH2}] (R = iPr (1a), Ph (1b)) have been synthesized by the reaction of the dimeric complex [IrCl­(μ-Cl)­(η5-C5Me5)]2 with allyldiisopropylphosphane (ADIP) and allyldiphenylphosphane (ADPP), respectively. The cationic complex [IrCl­(η5-C5Me5)­{κ3(P,C,C)-iPr2PCH2CHCH2}]+ (3+) has been prepared by the reaction of complex 1a with NaX (X = BPh4, PF6) in dichloromethane. The complex 3+ reacts with phosphanes and alkanethiolates to give the uncommon cationic complexes [IrCl­(η5-C5Me5)­{κ2(P,C)-iPr2PCH2CH­(PR2R′)­CH2}]+ (5+–7+) and IrCl­(η5-C5Me5)­{κ3(P,C,S)-iPr2PCH2CH­(SR)­CH2}]+ (13+ and 14+) by chemo- and regioselective addition of the nucleophiles to the π-olefin system. The reaction of 1a with LiBHEt3 gives the neutral complex [IrCl­(η5-C5Me5)­{κ2(P,C)-iPr2PCH2CH2CH2}] (10). For comparative purposes, the synthesis of the complex [RhCl­(η5-C5Me5)­{κ3(P,C,C)-iPr2PCH2CHCH2}]+ (4+) and its reactivity with phosphanes, hydride, and thiolates has been also assayed.