Reactions of a Trinuclear Ruthenium Complex Derived from 3-(2-Pyridyl)indene with Diphenylacetylene and Phenylacetylene: Insertion of Alkynes into the Ru−C bond

Electronic and steric effects of substituents in 1,3-diphenylprop-2-yn-1-one during its reaction with Ru3(CO)12

Electronic and steric effects of substituents of alkynyl ketones play important roles in regulating reaction pathways.

A concise synthesis of indene-based polycyclic compounds via FeCl3-catalyzed cascade cyclization

An efficient and straightforward protocol to complex indene-based polycyclic compounds via the cascade cyclization of propargylic alcohols and alkenes was developed. The catalyst FeCl₃, as an Earth-abundant and environment friendly transition metal salt, is attractive. This reaction proceeded through unusual C–C bond cleavage.

Intramolecular cyclization of a diruthenium complex: insight into the mechanism of heteroatom-directed intramolecular C-H/olefin coupling reactions

Complex 2, synthesized by the reaction of {(C5H4N)(μ2-η(5):η(1)-C9H5)}Ru3(CO)9 (1) with 1,5-hexadiene, could further transform to another diruthenium complex 3via intramolecular carbometalation. The results are relevant to the mechanism of transition-metal catalyzed heteroatom-directed intramolecular C-H/olefin coupling reactions.

Reactivity of a trinuclear ruthenium complex involving C–H activation and insertion of alkene

Synthesis, structure and reactivity of a pyridyl-substituted indenyl trinuclear ruthenium complex were researched.

Exploring bis(cyclometalated) ruthenium(II) complexes as active catalyst precursors: room-temperature alkene-alkyne coupling for 1,3-diene synthesis

Described is the development of a new class of bis(cyclometalated) ruthenium(II) catalyst precursors for C-C coupling reactions between alkene and alkyne substrates. The complex [(cod)Ru(3-methallyl)2] reacts with benzophenone imine or benzophenone in a 1:2 ratio to form bis(cyclometalated) ruthenium(II) complexes (1). The imine-ligated complex 1 a promoted room-temperature coupling between acrylic esters and amides with internal alkynes to form 1,3-diene products. A proposed catalytic cycle involves C-C bond formation by oxidative cyclization, β-hydride elimination, and C-H bond reductive elimination. This Ru(II)/Ru(IV) pathway is consistent with the observed catalytic reactivity of 1 a for mild tail-to-tail methyl acrylate dimerization and for cyclobutene formation by [2+2] norbornene/alkyne cycloaddition.

Ruthenium(II)/N-heterocyclic carbene catalyzed [3+2] carbocyclization with aromatic N-H ketimines and internal alkynes

A convenient and highly efficient synthesis of indenamines has been developed via ruthenium-catalyzed [3+2] carbocyclization under very mild conditions. A catalyst system of Ru(II) π-allyl precursor and N-heterocyclic carbene (NHC) ligand promotes facile coupling between aromatic N–H ketimines with internal alkynes at mild temperatures, without added oxidants or other metal salts, and in non-polar solvents. A proposed mechanism involves imine-directed activation of aromatic C–H bond, alkyne insertion, and carbocyclization by intramolecular imine insertion into Ru–alkenyl linkages.