Propargyl complexes of ruthenium

Article abstract of DOI:10.1016/0022-328X(92)83149-C

The first ruthenium-propargyl complexes CpL2RuCH2C<*>CPh (L = CO (1) and PPh3 (2)) were synthesized by reaction of ^- with PhC<*>CCH2Cl or PhC<*>CCH2OS(O)2C6H4Me-p and of Cp(PPh3)2RuCl with PhC<*>CCH2MgCl, respectively.In contrast, treatment of ^- with HC<*>CCH2Cl affords the ruthenium-η¹-allenyl complex Cp(CO)2RuCH=C=CH2 (3).Complex 1 is protonated by HBF4 * OEt2 to 2-CH2=C=CHPh)>BF4 (4a), which isomerizes within 2 h in acetone solution at room temperature to 2-CH2=C=CHPh)>BF4 (4b).Compound 4b reacts with Pt(PPh3)2(C2H4) to give the ruthenium-substituted platinum(II)-η³-allyl complex <(η³-CH2C(Ru(CO)2Cp)CHPh)Pt(PPh3)2>BF4 as the anti isomer quantitatively.Compound 1 undergoes facile <3 + 2> cycloaddition reactions with tetracyanoethylene (TCNE) and p-toluenesulfonyl isocyanate (TSI); the latter reaction in CH2Cl2 solution at 25 deg C proceeds slightly more rapidly (1.3 times) than the corresponding reaction of Cp(CO)2FeCH2C<*>CPh.With Co2(CO)8, 1 yields the trinuclear (CO)3Co(μ-η²-PhC<*>CCH2Ru(CO)2Cp)Co(CO)3, which undergoes very slow cleavage of the Ru-CH2 bond with CF3CO2H, and replacement of CO (at Co) with PPh3.The foregoing reactions are compared and contrasted with the corresponding reactions of Cp(CO)2FeCH2<*>CPh.Where a comparison has been made, 2 was found to react faster than 1; however, its chemistry tends to be complicated by the lower stability of products and a facile PPh3-CO ligand exchange.With TSI and Co2(CO)8, the products are analogous of those of 1, but with Fe2(CO)9, Cp(CO)(PPh3)RuCH2C<*>CPh and Fe(CO)4PPh3 are obtained instead of heteronuclear metal complexes.