Synthesis and Reactions of Five-Coordinate Mono- and Binuclear Thiocarbonyl−Alkenyl and Thioacyl Complexes of Ruthenium(II)

The reactions of [RuHCl(CS)(PPh3)3] with R1C⋮CR2 (R1 = R2 = H, Ph, CO2Me; R1 = H, R2 =
C6H4Me-4; R1 = C⋮CPh, R2 = Ph) lead to the five- or six-coordinate (R1 = R2 = CO2Me) σ-alkenyl
complexes [Ru(CR1CHR2)Cl(CS)(PPh3)2], the stilbenyl derivative being also formed by thermolysis
of [RuCl(κ2-O2CH)(CS)(PPh3)2] in the presence of diphenylacetylene. These complexes rapidly react
with carbon monoxide to provide the bidentate thioacyl complexes [Ru(η2-SCCR1CHR2)Cl(CO)(PPh3)2]
(R1 = R2 = H, Ph; R1 = H, R2 = Ph; R1 = C⋮CPh, R2 = Ph) or the σ-alkenyl tautomer [Ru(CR1CHR2)Cl(CO)(CS)(PPh3)2] (R1 = R2 = CO2Me), depending on the alkenyl substituent. The compound
[RuHCl(CS)(PPh3)3] reacts with 1/2 equiv of 1,4-diethynylbenzene to provide the coordinatively unsaturated
bimetallic species [(Ph3P)2(SC)ClRu(CHCHC6H4CHCH)RuCl(CS)(PPh3)2] in situ, which undergoes
migratory insertion on addition of carbon monoxide to give the bis(thioacyl) species [(Ph3P)2(OC)ClRu(η2-SCCHCHC6H4CHCHCS-η2)RuCl(CO)(PPh3)2]. On reaction with BSD (2,1,3-benzoselenadiazole),
[Ru(CHCH2)Cl(CS)(PPh3)2] gives [Ru(CHCH2)Cl(CS)(BSD)(PPh3)2] without migration of the alkenyl
group. The complex [RuHCl(CS)(BSD)(PPh3)2] results from the reaction of [RuHCl(CS)(PPh3)3] and
BSD, and this complex hydroruthenates alkynes cleanly to provide [Ru(CR1CHR2)Cl(CS)(BSD)(PPh3)2],
carbonylation of which leads to loss of BSD and formation of [Ru(η2-SCCR1CHR2)Cl(CO)(PPh3)2].
Addition of carboxylate donors R‘CO2- (R‘ = H, Fc) to the complexes [RuRCl(CS)(PPh3)2] (R =
CHCH2, C(C⋮CPh)CHPh) results in the complexes [RuR(κ2-O2CR‘)(CS)(PPh3)2], without migratory
insertion. A trimetallic example, Fe[C5H4CO2Ru{C(C⋮CPh)CHPh}(CS)(PPh3)2]2, was formed in the
corresponding reaction with 1,1‘-ferrocenedicarboxylic acid and Et3N. The crystal structures of the
complexes [Ru(CPhCHPh)Cl(CS)(PPh3)2], [Ru{C(C⋮CPh)CHPh}Cl(CS)(PPh3)2], [Ru{η2-SCC-(C⋮CPh)CHPh}Cl(CO)(PPh3)2], [Ru{C(C⋮CPh)CHPh}(κ2-O2CFc)(CS)(PPh3)2] and Fe[C5H4CO2Ru{C(C⋮CPh)CHPh}(CS)(PPh3)2]2 are reported.