scholarly journals Z-Selective Ring-Opening Metathesis Polymerization of 3-Substituted Cyclooctenes by Monoaryloxide Pyrrolide Imido Alkylidene (MAP) Catalysts of Molybdenum and Tungsten

2013 ◽  
Vol 32 (17) ◽  
pp. 4843-4850 ◽  
Author(s):  
Hyangsoo Jeong ◽  
Daniel J. Kozera ◽  
Richard R. Schrock ◽  
Stacey J. Smith ◽  
Jihua Zhang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Selective Ring Opening ◽  
And Tungsten

scholarly journals Selective ring-opening metathesis polymerization (ROMP) of cyclobutenes. Unsymmetrical ladderphane containing polycyclobutene and polynorbornene strands

2019 ◽  
Vol 15 ◽  
pp. 44-51 ◽  
Author(s):  
Yuan-Zhen Ke ◽  
Shou-Ling Huang ◽  
Guoqiao Lai ◽  
Tien-Yau Luh
Keyword(s):  
Methyl Ester ◽  
Ambient Temperature ◽  
Ring Opening ◽  
First Generation ◽  
Double Bonds ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Selective Ring Opening ◽  
Norbornene Derivatives

At 0 °C in THF in the presence of Grubbs first generation catalyst, cyclobutene derivatives undergo ROMP readily, whereas norbornene derivatives remain intact. When the substrate contains both cyclobutene and norbornene moieties, the conditions using THF as the solvent at 0 °C offer a useful protocol for the selective ROMP of cyclobutene to give norbornene-appended polycyclobutene. Unsymmetrical ladderphane having polycyclobutene and polynorbornene as two strands is obtained by further ROMP of the norbornene appended polycyclobutene in the presence of Grubbs first generation catalyst in DCM at ambient temperature. Methanolysis of this unsymmetrical ladderphane gives polycyclobutene methyl ester and insoluble polynorbornene-amide-alcohol. The latter is converted into the corresponding soluble acetate. Both polymers are well characterized by spectroscopic means. No norbornene moiety is found to be incorporated into polycyclobutene strand at all. The double bonds in the polycyclobutene strand are mainly in cis configuration (ca 70%), whereas the E/Z ratio for polynorbornene strand is 8:1.

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