A Unique Ruthenium Carbyne Complex: A Highly Thermo‐endurable Catalyst for Olefin Metathesis

Abstract

A cationic ruthenium carbyne complex was prepared and was found to initiate olefin metathesis reactions with good activities, which throws a new light on the design of a new type of ruthenium catalyst for RCM reactions. More importantly, no double bond isomerized by-product was observed even at elevated temperatures in reactions catalyzed by the new carbyne complex. A mechanism involving the in situ conversion of the ruthenium carbyne to a ruthenium carbene complex via addition of an iodide to the carbyne carbon was also proposed.

4-Methyltetrahydropyran as a Convenient Alternative Solvent for Olefin Metathesis Reaction: Model Studies and Medicinal Chemistry Applications

“…It shall be noted that under the same temperature, the general purpose catalysts, Ru3c and Ru4b , led to C–C double bond shift, producing substantial amounts of isomerized product 4′ (Table ), which, however, is significantly lower than this produced in the reaction of 3 catalyzed by Ru4b in 2-MeTHF (Table , entry 9) . Catalysts featuring symmetrical NHC ligands, such as SIPr and SIMes, are known to decompose under demanding reaction conditions to form various ruthenium species that are responsive for C–C double bond isomerization (shift), thus eroding the selectivity of the reaction. ,− …”

Fluorocarbene, fluoroolefin, and fluorocarbyne complexes of Rh

“…10 K. 11 Most of the isolable terminal carbyne complexes are complexes of metals of groups 6, 12 , 13 7, 13 , 14 and 8. 15 , 16 A few examples are known for group 5. 17 In group 9, one 18-electron complex has been fully characterized for Ir by Bergman et al ( Fig.…”

Exploring the electronic states of iodocarbyne: a theoretical contribution

“…The simplest prototype of a carbyne is the CH radical, but carbynes have been known for a long time to bind as trivalent ligands to transition metal complexes. 5,6 The role of ruthenium carbyne complexes as catalysts for olefin metathesis, for example, is discussed by Shao et al, 7 and the syntheses, structures and reactivity of heavier analogues of transition metals is the subject of a short review by Wu. 8 Halocarbynes or halomethylidynes have been generated by flash and laser photolysis of haloderivatives of C 1 and C 2 hydrocarbons.…”