Compounds [Ru(CO),(C,H4X-4)CI(PMe2Ph),] [ ( l a ) , X = H; ( l b ) , X = CI; (lc), X = Me; ( I d ) , X = OMe] react with Me0,CC-CC0,Me t o yield vinyl complexes [Ru(CO),{C(CO,Me)=C(CO,Me) (C6H,X-4)}CI(PMe,Ph),] (2a)-(Zd). The mechanism of formation appears to involve CO substitution b y the alkyne, combination of alkyne and aryl ligands, and finally re-entry of CO. Thermal decomposition of (2a)-(2d) yields products [ Ru (CO),{C( CO,Me)=C( C0,Me) ( t6H3X)}( PMe,Ph),] (3a)-(3d), complexes (4a)-(4d) whose structure is either [Ru(CO),{C(CO,Me)=C(CbO) (C,H,X-4)}( PMe,Ph),] or (5a)-(5d), and cis-[Ru(CO),CI,(PMe,Ph),]. Complex (3a) is also obtained from [Ru(CO),-(Me) Ph( PMe,Ph),] and MeO,CC=CCO,Me, while the reaction of [ Ru( CO),Me,( PMe,Ph),] with MeO,CCrCCO,Me yields [Ru(CO),{C(CO,Me)==C(CO,Me)Me}Me(PMe,Ph),] (6) [R~(CO>,{C(CbO)=C(CO,Me) (C6H4X-4)}( PMe,Ph),], alkenes CH(CO2Me)=C(CO,Me)(C,H,X-4) Some time ago we described reactions involving the insertion of alkynes into metal-chlorine bonds of ruthenium(I1) complexes. ' Alkynes are also known to insert into transition metal-alkyl and -aryl bonds. Thus [Ni(Ph)Br(PPh,),] has been shown to react with M e C X M e to yield [Ni(CMe=CMePh)Br(PPh3)2],2 while [Ni( C P h=CMePh)(acac)( PPh,)] (acac = acetylacetonate) has been obtained from [NiMe(acac)PPh,] and PhCr CPh.3 Insertion of CF,C=CCF, into the metal-methyl bond in the complexes rrun,r-[Pt(Me)X(PMe,Ph),] (X = C1, Br, or I) has been reported,, and there are other examples of the insertion of this alkyne and of Me0,CC-CC0,Me into platinum-methyl bond^.^,^In this paper, we report on a study of the reactions of a variety of organo-ruthenium(1r) complexes with the alkyne MeO,CCrCCO, Me. Several of the complexes used contained both a chloride ligand and an organic ligand, allowing us to determine whether alkyne insertion occurred preferentially into the Ru-Cl or Ru-C bond.
Results and DiscussionDetails of the i.r., 'H n.m.r., and I3C n.m.r. spectra of the products of the reactions described below are given in Tables 1, 2, and 3, respectively. A list of the formulae of the products and of the numbers assigned to them is given in Table 1.Recrc*/ions of tlw Complexes [Ru(CO),(C6H,X-4)C1( P-Me,Ph),] ~* i t t t Me0,CC-CC0,Me.-When a CHCI, solution of [Ru(CO),PhCl(PMe,Ph),] (la) (see Scheme 1; X = H) was warmed with an excess of Me0,CC-CC0,Me at 323 K, a slow reaction occurred. After several days the solvent was removed, and column chromatography of the residue followed by recrystallization yielded complex (2a) in high yield. Elemental analysis showed that (2a) contained the two reactants in a 1 : 1 f The ways in which phosphorus ligands may be used as stereochemical probes in ruthenium(r1) complexes have been described by Shaw and coworkers.'.'