Ring-opening metathesis polymerization of 8-membered cyclic olefins

2014 ◽  
Vol 5 (11) ◽  
pp. 3507 ◽  
Author(s):  
Henry Martinez ◽  
Ning Ren ◽  
Megan E. Matta ◽  
Marc A. Hillmyer
Keyword(s):  
Ring Opening ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Cyclic Olefins

scholarly journals Dinitrosyl rhenium complexes for ring-opening metathesis polymerization (ROMP)

2006 ◽  
Vol 78 (10) ◽  
pp. 1877-1887 ◽  
Author(s):  
Christian Manfred Frech ◽  
Olivier Blacque ◽  
Heinz Berke
Keyword(s):  
Phosphine Oxide ◽  
Ring Opening ◽  
Density Functional ◽  
Ring Opening Metathesis Polymerization ◽  
Olefinic Bond ◽  
Metathesis Polymerization ◽  
Molecular Weights ◽  
Cyclic Olefins ◽  
Phosphine Complexes ◽  
Unique Reaction

The treatment of benzene solutions of the cations [Re(NO)2(PR3)2][BArF4] (R = Cy and R = iPr; [BArF4] = tetrakis{3,5-bis(trifluoromethyl)phenyl}borate) with phenyldiazomethane afforded the moderately stable cationic rhenium(I) benzylidene dinitrosyl bis(trialkyl) phosphine complexes as [BArF4]- salts in good yields. The cationic rhenium dinitrosyl bisphosphine complexes catalyze the ring-opening metathesis polymerization (ROMP) of highly strained nonfunctionalized cyclic olefins to give polymers with relatively high polydispersity indices, high molecular weights, and Z configurations of the double bonds in the polymer chain backbones of over 80 %. The benzylidene derivatives are almost inactive in ROMP catalysis with norbornene and in olefin metathesis. NMR experiments gave first hints for the initial formation of carbene complexes when [Re(NO)2(PR3)2][BArF4] was treated with norbornene. The carbene formation is initiated by an unique reaction sequence where the cleavage of the strained olefinic bond starts with phosphine migration forming a cyclic ylid carbene complex. The [2+2] addition of a norbornene molecule to the Re=C bond leads to the rhenacyclobutane complex, which is expected to be converted into an iminate complex by attack of the ylid function onto one of the NNO atoms followed by Wittig-type phosphine oxide elimination. The formation of phosphine oxide was confirmed by NMR spectroscopy. This species is thought to drive the ROMP metathesis with alternating rhenacyclobutane formations and cycloreversions. The proposed mechanism is supported by density functional theory (DFT) calculations.

Facile in situ generation of highly active (arylimido)vanadium(v)–alkylidene catalysts for the ring-opening metathesis polymerization (ROMP) of cyclic olefins by immediate phenoxy ligand exchange

2018 ◽  
Vol 54 (96) ◽  
pp. 13559-13562 ◽  
Author(s):  
Hitomi Hayashibara ◽  
Xiaohua Hou ◽  
Kotohiro Nomura
Keyword(s):  
Ligand Exchange ◽  
Ring Opening ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Cyclic Olefins ◽  
Highly Active ◽  
In Situ Generation

Remarkably active vanadium(v)–alkylidene catalysts for the ring-opening metathesis polymerization of cyclic olefins can be generated in situ upon addition of C6F5OH or C6Cl5OH.

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