PHOSPHAALKYNE HYDROMETALATION - SYNTHESIS AND REACTIVITY OF THE COMPLEXES [RU(P=CHCME3)CL(CA)(PPH3)(2)] (A = O, S)

The reaction of [RuHCl(CO)(PPh3)(3)] (1a) with P=CCMe3 results in the formation of the phosphaalkenyl complex [Ru(P=CHCMe3)Cl(CO)(PPh3)(2)] (2a). Being coordinatively unsaturated, 2a reacts reversibly with CO t o provide [Ru(P=CHCMe3)Cl(CO)(2)(PPh3)(2)] (3) and with isonitriles (C NR) to provide [Ru(P=CHCMe3)Cl(CNR)(CO)(PPh3)(2)] [R = CMe3 (4a), C6H3 Me2-2,6 (4b)]. With an excess of CNCMe3, the salt [Ru(P=CHCMe3)(CNR)(2 )(CO)(PPh3)(2)]Cl 5(Cl) is obtained. The anionic bidentate ligand K[H2 B(bta)(2)] (bta = benzotriazolyl) reacts with 2a via chloride displace ment to provide [Ru(P=CHCMe3){H2B(bta)(2)}(CO)(PPh3)(2)] (6) while the facially tridentate macrocycle 1,4,7-trithiacyclononane ([S]aneS(3)) provides [Ru(P=CHCMe3)(CO)(PPh3)([9]aneS(3))]Cl 7(Cl). The thiocarbony l complex [Ru{P=CHCMe3)Cl(CS)(PPh3)(2)] (2b), obtained from [RuHCl(CS) (PPh3)(3)] (1b) and P=CCMe3, reacts with [Et2NH2][S2CNEt2] or [9]aneS( 3) to provide [Ru(P=CHCMe3)(S2CNEt2)(CS)(PPh3)(2)] (8) and [Ru(P=CHCMe 3)(CS)(PPh3)([9]aneS(3))]Cl 9(Cl), respectively. The salt 5(Cl) or the neutral complex 4a react slowly with air (accelerated by base), to pr ovide the lambda(5)-phosphaalkenyl-metallacycle [Ru{P(=O)C(CMe3)C(=O)} (CNCMe3)(2)(PPh3)(2)] (10). The reactions of 1a with sodium formate or ferrocene carboxylate provides the complexes [Ru(P=CHCMe3)(O2CR)(CO)( PPh3)(2)] (R = H (11a), C5H4Fe(eta-C5H5) (11b)) The X-ray crystal stru cture of 11a is reported.