One-pot syntheses of alkenyl-phosphonio complexes of ruthenium(II), rhodium(III) and iridium(III) bearing p-cymene or pentamethylcyclopentadienyl groups

Reaction of [(p-cymene)RuCl2(PPh3)] (1) or [Cp∗MCl2(PPh3)] (Cp∗ = C5Me5) (3a: M = Rh; 4a: M = Ir) with 1-alkynes and PPh3 were carried out in the presence of KPF6, generating the corresponding alkenyl-phosphonio complexes, [(p-cymene)RuCl(PPh3){CHdouble bond; length as m-dashCR(PPh3)}](PF6) (2a: R = Ph; 2b: R = p-tolyl) or [Cp∗MCl(PPh3){CHdouble bond; length as m-dashCPh(PPh3)}](PF6) (5: M = Rh; 6: M = Ir). Similar reactions of complexes [Cp∗RhCl2(L1)] (3a: L1 = PPh3; 3c: L1 = P(OMe)3) with L2 (L2 = PPh3, PMePh2, P(OMe)3) gave [Cp∗RhCl(L1)(L2)](PF6) (7bb: L1 = L2 = PMePh2; 7ca: L1 = P(OMe)3, L2 = PPh3; 7cc: L1 = L2 = P(OMe)3). Alkenyl-phosphonio complex 5 was treated with P(OMe)3 or 2,6-xylyl isocyanide, affording [Cp∗RhCl(L){CHdouble bond; length as m-dashCPh(PPh3)}](PF6) (8a: L = P(OMe)3; 8b: L = 2,6-xylNC). X-ray structural analyses of 2a, 6 and 8a revealed that the phosphonium moiety bonded to the Cβ atom of the alkenyl group are E configuration.