Polyazolyl Chelate Chemistry. 7.1Reactivity of the Complexes [MCl(PPh3)2{HB(pz)3}] (M = Ru, Os; pz = Pyrazol-1-yl)

The substitution chemistry of the complex [RuCl(PPh 3 ) 2 {HB(pz) 3 }] ( 1 ) is reported. Treating 1 with the phosphines bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), or 1,1‘-bis(diphenylphosphino)ferrocene (dppf) provides the complexes [RuCl(dppm){HB(pz) 3 }] ( 2 ), [RuCl(dppe){HB(pz) 3 }] ( 3 ), or [RuCl(dppf){HB(pz) 3 }] ( 4 ), respectively. Reactions of 1 with pivaloisonitrile (CNCMe 3 ) are solvent dependent: In neat dichloromethane or tetrahydrofuran the reaction of 1 with CNCMe 3 provides the neutral complex [Ru(CNCMe 3 )Cl(PPh 3 ){HB(pz) 3 }] ( 5 ), while the salt [Ru(CNCMe 3 )(PPh 3 ) 2 {HB(pz) 3 }]PF 6 ( 6·PF 6 ) is obtained when the reaction is carried out in dichloromethane/methanol mixtures in the presence of NH 4 PF 6 . The reaction of 4 with CNCMe 3 and NH 4 PF 6 provides the salt [Ru(CNCMe 3 )(dppf){HB(pz) 3 }]PF 6 ( 7·PF 6 ). The bis(isonitrile) salt [Ru(CNCMe 3 ) 2 (PPh 3 ){HB(pz) 3 }]PF 6 ( 8·PF 6 ) results from the reaction of 1, 5, or 6·PF 6 with excess CNCMe 3 in thf/methanol. The reaction of 1 with Na[S 2 CNMe 2 ] provides the complex [Ru(S 2 CNMe 2 )(PPh 3 ){HB(pz) 3 }] ( 9 ); however similar reaction of 1 or [Ru(NCMe) 2 (PPh 3 ){HB(pz) 3 }]PF 6 with Na[O 2 CH] failed to cleanly provide [Ru(O 2 CH)(PPh 3 ){HB(pz) 3 }] ( 10 ), although this could be characterized spectroscopically. Rather, the ultimate product of these reactions was the hydrido complex [RuH(PPh 3 ) 2 {HB(pz) 3 }] ( 11 ), which could also be obtained in high yield from the reaction of 1 with NaOMe. In a similar manner, reaction of 4 with methanolic NaOMe provided [RuH(dppf){HB(pz) 3 }] ( 12 ). The reactions of 1 and 4 with alkynes are solvent dependent: Treating 1 with HC⋮CR (R = C 6 H 4 Me-4, CPh 2 OH) in thf provides, respectively, the vinylidene complex [RuCl( C CHC 6 H 4 Me-4)(PPh 3 ){HB(pz) 3 }] ( 13 ) and the allenylidene complex [RuCl( C C CPh 2 )(PPh 3 ){HB(pz) 3 }] ( 14 ), while the reaction of 1 with HC⋮CC 6 H 4 Me-4 in a mixture of thf and methanol provides the alkynyl complex [Ru(C⋮CC 6 H 4 Me-4)(PPh 3 ) 2 {HB(pz) 3 }] ( 15 ). The reaction of 1 with HC⋮CCPh 2 OH in the presence of AgPF 6 provides the allenylidene salt [Ru( C C CPh 2 )(PPh 3 ) 2 {HB(pz) 3 }]PF 6 ( 16·PF 6 ), and similar treatment of 4 provides [Ru( C C CPh 2 )(dppf){HB(pz) 3 }]PF 6 ( 17·PF 6 ). The reaction of 4 with HC⋮CC 6 H 4 Me-4 and AgPF 6 provides the vinylidene salt [Ru( C CHC 6 H 4 Me-4)(dppf){HB(pz) 3 }]PF 6 ( 18·PF 6 ), deprotonation of which (NaOMe) provides [Ru(C⋮CC 6 H 4 Me-4)(dppf){HB(pz) 3 }] ( 19 ). The allenylidene salt ( 16·PF 6 ) with NaOMe provides the γ-alkoxyalkynyl complex [Ru(C⋮CCPh 2 OMe)(PPh 3 ) 2 {HB(pz) 3 }] ( 20 ). The complex [OsCl(PPh 3 ) 2 {HB(pz) 3 }] ( 21 ) is obtained from the reaction of [OsCl 2 (PPh 3 ) 3 ] with K[HB(pz) 3 ] and is converted by KOH in reluxing 2-methoxyethanol to the hydride complex [OsH(PPh 3 ) 2 {HB(pz) 3 }] ( 22 ). The vinylidene complex 13 reacts with [Et 2 NH 2 ][S 2 CNEt 2 ] to provide the metallacyclic vinyl complex [Ru{C( CHC 6 H 4 Me-4)SC(NEt 2 )S}(PPh 3 ){HB(pz) 3 }] ( 23 ). Similarly the complex 14 and the salt 16·PF 6 react with Na[S 2 CNMe 2 ] to both provide the metallacyclic allenyl complex [Ru{C( C CPh 2 )SC(NMe 2 )S}(PPh 3 ){HB(pz) 3 }] ( 24 ). These reactions represent the first examples of the coupling of dithiocarbamates with vinylidene and allenylidene ligands. The complexes 5 and [RuCl(CS)(PPh 3 ){HB(pz) 3 }] ( 25 ) and the salt ( 16·PF 6 ) were characterized crystallographically.