Carbon-sulfur and carbon-phosphorus bond cleavage and subsequent carbon-carbon bond formation promoted by an active ruthenium(0) species

Reaction of RuH2(CO)(PPh3)3 (1) with thiophene in the presence of styrene gives the novel diruthenium complex (Ph3P)(OC)Ru(μ-(1Z,3Z)-PhCHCHCHCHS)(μ-PPh2)Ru(CO)(PPh3) (2) with a unique bridging 4-phenyl-1,3-butadienethiolato moiety made up of the 1-thiapenta-2,4-dien-1,5-diyl and phenyl groups, which are derived from the thiophene and triphenylphosphine, respectively. Treatment of 2 on a preparative thin-layer chromatography plate of alumina or silica gel causes Z−E isomerization of the bridging moiety to give (Ph3P)(OC)Ru(μ-(1Z,3E)-PhCHCHCHCHS)(μ-PPh2)Ru(CO)(PPh3) (5). The molecular structures of 2 and 5 have been determined by X-ray structure analyses.