Insertion of Acetylene and Nitriles into a Ru−C Bond of a Dicationic Triruthenium Complex Having a μ₃-η³-C₃ Ring: Formation of Six-Membered Ruthenacycles on a Triruthenium Core

Abstract

A triruthenium complex having a μ3-ruthenacyclohexadienyl moiety, [(Cp*Ru)2{Cp*Ru(μ3-η2:η2-CHCMeCH−CHCH−)}(μ3-CH)]+ (9), was synthesized by the reaction of an equilibrating mixture of dicationic complexes having a μ3-η3-C3 ring, [(Cp*Ru)3(μ3-η3-C3H2Me)(μ3-CH)(μ-H)]2+ (2a and 2b), with acetylene. The protonation of 9 resulting in the formation of a dicationic μ3-ruthenacyclohexadienyl complex, [(Cp*Ru)2{Cp*Ru(μ3-η2:η2-CH−CMeCHCHCH−)}(μ3-CH)(μ-H)]2+ (10), strongly indicates that the hydrido ligand of 2 was removed as a proton after the six-membered metallacycle was formed by the insertion of an acetylene molecule into a Ru−C bond. The thermolysis of 9 resulted in an isomerization of the metallacycle moiety via the formation of a μ3-cyclopentadienyl intermediate and quantitatively afforded a μ3-4-methylruthenacyclohexadienyl complex, [(Cp*Ru)2{Cp*Ru(μ3-η3:η2-CHCHCMe−CHCH−)}(μ3-CH)]+ (13). Nitriles also inserted into a Ru−C bond of 2 and afforded a series of dicationic 2-azaruthenacyclohexadienyl complexes, [(Cp*Ru)2{Cp*Ru (μ3-η2:η3-NHCR−CHCMeCH−)}(μ3-CH)]2+ (18a: R = Me, 18b: R = Et, 18c: R = Ph).

Reaction of FcCCC(O)R (Fc = ferrocenyl) with Ru3(CO)12 leading to unexpected nitro-group reduced ruthenoles and 1,2-CO-inserted triruthenium clusters

“…The thermal reactions of 1,3-ynones (1)(2)(3)(4)(5)(6) with Ru 3 (CO) 12 were carried out in toluene at 90 C under nitrogen atmosphere. The reaction courses were monitored by TLC technique.…”

“…In this paper, we examined in detail the reaction processes of Ru 3 (CO) 12 with six FcC^CC(O)R (Fc ¼ ferrocenyl; R ¼ Ph 1; 2thienyl (2); 4-CH 3 O-Ph (3); 4-NH 2 -Ph (4); 4-NO 2 -Ph 5; ferrocenyl (6)) compounds. In the compounds 1-6, the selected groups at their carbonyl sides are phenyl (1) and 2-thienyl (2) rings with no substituents, phenyl rings with electron-donating groups (3 and 4) and electron-withdrawing group (5), and a sterically hindered ferrocenyl group (6). The coordination and couplings of the alkynyl ketones with Ru 3 (CO) 12 formed a series of ruthenium clusters.…”

“…bonds. 2 To understand the related activated mechanisms, reactions of Ru 3 (CO) 12 with NHCs, 3 arenes, 4 alkenes 5 and alkynes 6 were extensively investigated. In recent years, some carbonyl ruthenium compounds formed via Ru 3 (CO) 12 and unsaturated hydrocarbons have been used in catalytic reactions.…”

Reversible Transformation of a μ3-η3-C3 Ring into μ3-η2-Ethyne and μ-Vinylidene Ligands at a Triruthenium Site upon Deprotonation and Protonation

“…We previously reported the synthesis and reactivity of the dicationic triruthenium complex 2 , which contains a face-capping μ 3 -η 3 -C 3 ring. , Because of the flexibility of the μ 3 -η 3 -C 3 ring skeleton at the dicationic Ru 3 site, 2 shows unique reactivity toward nucleophiles, such as H 2 O, acetylene, and acetonitrile via ring opening of the μ 3 -η 3 -C 3 skeleton followed by C–O or C–C bond formation (Scheme ). In contrast to 2 , the monocationic derivative 3a , which was obtained by the deprotonation of 2 , is air-stable and does not react with nucleophiles . This fact suggests the importance of the electrophilic Ru 3 core for the functionalization of the C 3 moiety.…”

Computational Study of C−C Coupling on Diruthenium Bis(μ-vinyl) Ethylene π-Complex

“…These complexes have been found to be efficient in bond activation reactions, such as H−H, C−H, − Si−H, Si−C, − C−C, , P−C, , C−S, C−N, and N−N − bond cleavages. Also, these complexes have been shown to favor reactions affording new C−H, C−Si, C−C, − and C−O bonds …”