《Metathesis of norbornene-derivatives bearing trimethylsilyl groups using Ru-alkylidene catalysts: An experimental and computational study》 was written by Zarate-Saldana, Daniel; Landeros-Rivera, Bruno; Cruz-Morales, Jorge A.; Gutierrez, Selena. Safety of Benzylidenebis(tricyclohexylphosphine)dichlororuthenium And the article was included in Journal of Organometallic Chemistry in 2020. The article conveys some information:
The monomer synthesis and ring-opening metathesis polymerization (ROMP) of cis-5-norbornene-exo-2,3-dicarboxylic anhydride (1a) and 7-syn-trimethylsilyl-cis-5-norbornene-exo-2,3-dicarboxylic anhydride (1b) mediated by ruthenium-alkylidene catalysts (I, II and III) were exptl. carried out. Metathesis reaction pathways of 1a and 1b monomers using II have been studied at PBE-D3(BJ)/def2-TZVP level of theory, employing the SMD model for simulation of 1,2-dichloroethane solvent. The calculations unravel that reactivity difference between 1a and 1b towards ruthenium alkylidene complex II is due to the fact that the intermediate π-complex formation was found in the 1a reaction pathway but was absent in the 1b one. Moreover, there are marked differences in the formation processes of the metallacyclobutane intermediaries 5a and 5b, the first is an exergonic process (-8.3 kcal/mol) and the last one is an endergonic process (2 kcal/mol), in addition to the high activation energy of the monomer 1b (15.8 kcal/mol) compared with 1a (5.5 kcal/mol). Such differences are attributed to the high steric impediment imposed by -Si(CH3)3 over the double bond (syn conformation). Using quantum theory of atoms in mols. (QTAIM) it was possible to analyze successfully the mechanistic pathway of metathesis reaction for both monomers, complementing the results obtained by DFT energetic anal. After reading the article, we found that the author used Benzylidenebis(tricyclohexylphosphine)dichlororuthenium(cas: 172222-30-9Safety of Benzylidenebis(tricyclohexylphosphine)dichlororuthenium)
Benzylidenebis(tricyclohexylphosphine)dichlororuthenium(cas: 172222-30-9) is the first metathesis catalyst to be widely used in organic synthesis. It is useful for acyclic diene metathesis polymerization (ADMET), Ring-Opening Metathesis Polymerization (ROMP) of strained cyclic olefins, ring opening metathesis (ROM), and so on.Safety of Benzylidenebis(tricyclohexylphosphine)dichlororuthenium
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics