Unprecedented coupling of vinylidene and allenylidene ligands with dithiocarbamates: X-ray structure of [Ru{C(CCPh 2)SC(NMe 2)S}(S 2CNMe 2)(CO)(PPh 3)

Abstract

The reaction of [RuCl(PPh 3) 2{HB(pz) 3}] (pz=pyrazol-1-yl) with 4-ethynyl toluene provides [RuCl(CCHC 6H 4Me-4)(PPh 3){HB(pz) 3}] ( 1a) which reacts with [Et 2NH 2][S 2CNEt 2] to give the metallacyclic alkenyl complex [Ru{C(CHC 6H 4Me-4)SC(NEt 2)S}(PPh 3){HB(pz) 3}] ( 2). The reaction of [RuCl(PPh 3) 2{HB(pz) 3}] with diphenylpropynol and Ag[PF 6] however provides [Ru(CCCPh 2)(PPh 3) 2{HB(pz) 3}]PF 6 ( 3) or in the absence of silver salts, the neutral complex [RuCl(CCCPh 2)(PPh 3){HB(pz) 3}] ( 4). Both ( 3) and ( 4) react with Na[S 2CNMe 2] to give the metallacyclic allenyl complex [Ru{C(CCPh 2)SC(NMe 2)S}(PPh 3){HB(pz) 3}] ( 5). Treatment of [RuHCl(CO)(PPh 3) 3] with diphenylpropynol and Na[S 2CNMe 2] provides [Ru(CHCHCPh 2OH)(S 2CNMe 2)(CO)(PPh 3) 2] which reacts with excess diphenylpropynol to give the alkynyl complex [Ru(CCCPh 2OH)(S 2CNMe 2)(CO)(PPh 3) 2]. Protonation of this complex with HBF 4 provides the allenylidene complex [Ru(CCCPh 2)(S 2CNMe 2)(CO)(PPh 3) 2]BF 4 ( 6) which reacts with Na[S 2CNMe 2] to give a kinetic isomer ( 7k) and ultimately a structurally characterised thermodynamic isomer of the metallacyclic allenyl complex [Ru{C(CCPh 2)SC(NMe 2)S}(S 2CNMe 2)(CO)(PPh 3)] ( 7t).