Reactivity of κ( P )‐Alkenylphosphane Rhodium(III) and Iridium(III) Complexes toward Nucleophilic Reagents

The reactivity of the complexes [RhCl 2 ( η 5 ‐C 5 Me 5 ){ κ ( P ) ‐ Ph 2 P(CH 2 ) 2 CH=CH 2 }] ( 1 ), [MCl 2 ( η 5 ‐C 5 Me 5 ){ κ ( P )‐R 2 PCH 2 CH=CH 2 }] (M=Rh, R=Ph ( 3 a ), i Pr ( 3 b ); M=Ir, R=Ph ( 4 a ), i Pr ( 4 b )) towards various nucleophilic reagents (carbon‐donor, nitrogen‐donor and phosphorus‐donor) in the presence of a halogen abstractor has been studied. The rhodium e iridium complexes undergo metal coordination of the ligand (L=CNR, CO, Py, P(OPh) 3 ) to give the new cationic complexes [MCl( η 5 ‐C 5 Me 5 )(L){ κ ( P )‐R 2 P(CH 2 ) n CH=CH 2 }][BPh 4 ] (M=Rh, Ir; L=CNR, CO, Py, P(OPh) 3 ) ( 5 ‐ 19 a,b ). However, the reaction with phosphanes follows a different way depending on the metal. While the rhodium complexes 3 a,b give the expected products [RhCl( η 5 ‐C 5 Me 5 )(L){ κ ( P )‐R 2 PCH 2 CH=CH 2 }][BPh 4 ] ( 20 a,b , 21 a and 22 a ), the iridium complex 4 a suffer addition of the phosphane to the C=C affording the complexes [IrCl(η 5 ‐C 5 Me 5 ){ κ 2 ( P,C )‐Ph 2 PCH 2 CH(PR ’Ph 2 )CH 2 }][BPh 4 ] (R ’ = Me ( 23 a ), Ph ( 24 a )).