Synthesis and radical ring-opening polymerization of 1,2-dicarbomethoxy-3-vinylcyclobutane

Abstract

Although highly strained vinylcyclopropanes have been reported to undergo ringopening polymerization in the presence of radical initiators,'i2 the radical ring-opening polymerization of vinylcyclobutanes as highly strained as cyclopropanes has not been studied. Although the polymerization of methylene-cyclobutane by Ziegler-Natta catalysts and cationic catalyst^^,^ has been reported to obtain polymers predominantly

Computational evaluation of radical ring‐opening polymerization

“…As indicated in Table 1, 16 monomers were grouped into monomers polymerized via (1) selective ring-opening polymerization (1-7), 34 (2) both ring-opening and vinyl-type polymerizations (8)(9)(10)(11), and (3) selective vinyl-type polymerization (12)(13)(14)(15)(16). The ring-opening degrees of the polymerizations of the monomers polymerized via partial ring opening (i.e., 8-11) exceed 80%, indicating the high tendencies of their radical ring openings.…”

“…For instance, a radical produced by an attack of a radical onto the vinyl group of 1-phenyl-2-vinyloxirane (1), 3,4 carrying a strained oxirane ring, selectively ring-opens to afford a resonance-stabilized benzylic radical. In contrast, the radical polymerization of 1-phenyl-2-vinyl-3,5-dioxolan-4-one, carrying a thermodynamically stable five-membered ring, propagates without ring opening, although the presumably ring-opened radical is also a resonance-stabilized benzylic radical (14). 18 On the other hand, some monomers that seem to meet the aforementioned factors are not polymerized via ring-opening factions; for example, an exomethylene cyclobutane, 1-cyano-1-methoxycarbonyl-3-methylenecyclobutane (16), 21 is polymerized via selective vinyl-type polymerization despite its strained ring and resonance-stabilizing groups.…”

“…Relationship between Dd and DE { values in the ring-opening processes calculated by (a) AM1, (b) PM3, and (c) DFT B3LYP/6-31G*//AM1: (n) selective ring-opening monomers(1-7), (l) partial ring-opening monomers(8)(9)(10)(11), and (~) selective vinyltype polymerization monomers(12)(13)(14)(15)(16).…”

Radical ring-opening polymerization

“…10 A vinylcyclobutane also undergoes RROP to afford a polymer with double bonds in the main chain similarly to vinylcyclopropanes (Scheme 12). 11 Vinyloxirane 12 and vinylthiirane, 13 analogues of a vinylcyclopropane undergo RROP, but the polymers formed contain some indeterminable structures, probably because of some side reactions such as hydrogen radical abstraction at the allylic positions (Scheme 13). Bifunctional vinyloxiranes undergo radical polyaddition with dithiols to afford poly(ether sulfide)s with double bonds in the main chain (Scheme 14).…”

Ring-opening polymerization of heterocycles bearing substituted and unsubstituted exo-methylene groups - a review

“…However, tungsten-(VI)-chloride as the catalyst produces only low molecular weight polymers having almost no ring-opened units [72]. Finally the copolymerization of 50 with vinyl monomers is reported [77,79].…”