Copolymerization of 5‐norbornen‐2‐yl acetate with cycloalkenes by the metathesis catalyst WCl₆/(CH₃)₄Sn

Abstract

Ring-opening metathesis copolymerization of 5-norbornen-2-yl a) acetate (NBEAc; 80% endo) with cyclooctene (COE) and norbornene b, (NBE) was studied using WCI6/(CH3),Sn as catalytic system. The copolymerization parameters (r, = r2 = 1 for the NBEAc/NBE system and rl = l / r , = 132 for the NBEAc/COE system) show that the reactivity of the monomers is not affected by the presence of an ester substituent but that it depends on the structure of the hydrocarbon cycle. Thus the well known inhibition effect of the ester group may be concluded not to lie in the propagation step of the catalytic cycle.

Synthesis and ROMP activity of aminophenol-substituted tungsten(VI) and molybdenum(VI) complexes

“…Mo complex 6 exhibited the highest activity delivering high molecular weight poly(NBEAc) in a quantitative yield at relatively low catalyst/monomer molar ratio (1/330). This activity was significantly higher than that of classical systems based on W and Mo chlorides [17][18][19].…”

Synthesis and Functionalization of ROMP-Based Gradient Copolymers of 5-Substituted Norbornenes

“…Since the reactivities of ROMP monomers toward well-defined ROMP catalysts are known to be influenced by the ring strain of the monomer, − the stability of the propagating carbene, and steric effects, ,− similar reactivities for 3a and 3b are expected: the discriminating substituents are simply too far from the olefin moiety to have a large effect. We are aware of only one other example where reactivity ratios for 5-subsituted norbornenes are found to be similar and close to unity 1 Synthesis of Monomers …”

“…Ilker and Coughlin determined the reactivity ratios for endo - N -ethyl-7-oxanobornene-2,3-dicarboxylimide and cyclooctene (COE) in the presence of 1 to be 0.04 and 0.08, respectively, allowing for the formation of an almost perfectly alternating copolymer . Balcar and Dosedlová found the reactivity ratios for 5-norbornene-2-yl acetate and COE and norbornene (NBE) to be r 1 = 1 and r 2 = 132 and r 1 = r 2 = 1, respectively, using WCl 6 /(CH 3 ) 4 Sn . Reactivity ratios for NBE and COE were determined to be 8.9 and 0.51, respectively, using WCl 6 /Ph 4 Sn .…”

“…We are aware of only one other example where reactivity ratios for 5-subsituted norbornenes are found to be similar and close to unity. 52 To date, differences in the reactivities between ROMP monomers toward a specific catalyst system are typically framed in terms of the differences in their homopolymerization rates and the observed differences in monomer conversion during copolymerization; [53][54][55][56][57][58] measured reactivity ratios are rare. Ilker and Coughlin determined the reactivity ratios for endo-N-ethyl-7oxanobornene-2,3-dicarboxylimide and cyclooctene (COE) in the presence of 1 to be 0.04 and 0.08, respectively, allowing for the formation of an almost perfectly alternating copolymer.…”

“…59 Balcar and Dosedlova ´found the reactivity ratios for 5-norbornene-2-yl acetate and COE and norbornene (NBE) to be r 1 ) 1 and r 2 ) 132 and r 1 ) r 2 ) 1, respectively, using WCl 6 /(CH 3 ) 4 Sn. 52 Reactivity ratios for NBE and COE were determined to be 8.9 and 0.51, respectively, using WCl 6 /Ph 4 Sn. 60 Monakov et al also measured reactivity ratios for NBE with various 7-oxonorbornenes in the presence of RuCl 3 ‚3H 2 O.…”