Consideration of the mechanism of the transition metal catalyzed olefin metathesis reaction. Metathesis of cis,cis-2,8-decadiene

Functionality Dependent Olefin Activity in Acyclic Diene Metathesis Polymerization: Mass Spectrometry Characterization of Amino Acid Functionalized Olefins

“…The olefin's activity, determined by steric or electronic functional group properties, affects metathesis kinetics, which in our case would determine the ratio of the rate of metathesis versus the rate of isomerization and establish the final distribution of ADMET products. Previously performed kinetics studies on olefin metathesis isomerization examined geometric (cis/trans) isomerization and suggested the presence of a link between the metathesis and isomerization relative rates and the manner of olefin coordination to the catalyst. − Kinetics studies of olefin structural (double bond migration) isomerization in ADMET polymerization, on the other hand, led to the conclusion that metathesis and isomerization occur concurrently while competing in the initial stages of the polymerization, but after metathesis finishes, only isomerization takes place. ,, Metathesis (dimerization) of the model compound 1-octene with catalyst 1 confirmed that the described kinetic pathway is preferred in ADMET polymerization since it led to the formation of 7-tetradecene as a nonisomerized main product (NI) and revealed an asymmetric distribution of isomerized chains around NI in the gas chromatograms (GC) . This kinetic outcome, where the distribution is shifted toward the light products, with few heavy chains formed, ensures that isomerization occurs at the same time as metathesis on both the monomer and the polymerization products.…”

“…Previously performed kinetics studies on olefin metathesis isomerization examined geometric (cis/trans) isomerization and suggested the presence of a link between the metathesis and isomerization relative rates and the manner of olefin coordination to the catalyst. [51][52][53] Kinetics studies of olefin structural (double bond migration) isomerization in ADMET polymerization, on the other hand, led to the conclusion that metathesis and isomerization occur concurrently while competing in the initial stages of the polymerization, but after metathesis finishes, only isomerization takes place. 32,37,54 Metathesis (dimerization) of the model compound 1-octene with catalyst 1 confirmed that the described kinetic pathway is preferred in ADMET polymerization since it led to the formation of 7-tetradecene as a nonisomerized main product (NI) and revealed an asymmetric distribution of isomerized chains around NI in the gas chromatograms (GC).…”

ADMET: Metathesis polycondensation

“…Although not all considerations could be explained, Katz envisioned applications forthcoming along with initiator and catalyst developments. Just after Katz's mechanistic report, Grubbs and Hoppin released support for the metal–carbene mechanism including vigorous isotopic labeling and isolation of the various metathesis pathway products 28. Katz proceeded in developing low oxidation state electrophilic Fischer carbenes promoting ROMP but unsuccessful in promoting olefin metathesis.…”

Cp2TiCH2 complexes in synthetic applications

“…This complex has been developed as a useful reagent for the conversion of esters into vinyl ethers (6). The reaction has been observed to be very general and is now being used in a number of complex syntheses by other groups (2) Reactions of I with olefins were studied as a part of our investigation of the mechanism of the olefin metathesis reaction (8). Unexpectedly, we found that a series of stable metallacycles (Il) could be prepared from a wide range of olefins (9,10).…”