Functional Monomers and Polymers CLVIII. Asymmetric Inclusion Polymerization of Cyclic Diene Monomers in a Deoxycholic Acid Canal

Tsuzuki

Takemoto

et al. 1988

Polym J

Self Cite

Asymmetric inclusion polymerization is an excellent way for obtaining highly stereoregular and optically active polymers by "through space" asymmetric induction. 1 However, applicable monomers are so far limited to only methyl-substituted 1,3-butadienes (BO), such as 1,3-pentadiene, 2 2-methyl-1,3-pentadiene, 3 2,4-hexadiene, 4 and 1,3-cyclodienes. 5 In spite of impressive progress in asymmetric synthesis over the past decade, 6 there seem to be only a few studies on asymmetric polymerization of BO derivatives except for the inclusion method.thermally stable propagating radicals in the canals. This finding enabled us to challenge the inclusion polymerization of many diene monomers not applicable so far.In a series of extensive studies on inclusion polymerization using deoxycholic acid (OCA, I) and apocholic acid (ACA, II) as the host molecules, we showed that even butadiene monomers with bulky and/or polar substituent groups can be polymerized in the canals of the hosts. 7 • 8 The reason for the success lies in the possible prolonged postpolymerization due to We report here the first example of asymmetric inclusion polymerization of five prochiral monomers, that is, propyl, isopropyl, butyl, in OCA and ACA canals by long-lived propagating radicals. ESR observation of the propagating radicals is also described.

mentioning

confidence: 99%

Functional Monomers and Polymers CLXVII. Asymmetric Inclusion Polymerization of 1-Alkyl-1,3-butadienes in Deoxycholic Acid and Apocholic Acid Canals by Long-Lived Propagating Radicals

Tsuzuki

Takemoto

et al. 1988

Polym J

Self Cite

Functional monomers and polymers, 163. Inclusion polymerization of cyclic diene monomers in deoxycholic acid canals

Tsutsumi

Takemoto

1989

Angew. Makromol. Chem.

Inclusion polymerization of cyclic diene monomers, such as cyclopentadiene, 1,3cyclohexadiene, 1,3-~ycloheptadiene, 1,5-cyclooctadiene, and 2,5-norbornadiene, was studied, using deoxycholic acid (DCA) as the canal component.The formation of monomer-DCA adducts was observed, however, the polymerization occurred only in the case of cyclopentadiene, 1,3-cyclohexadiene, or 1,3-cycloheptadiene. The polymers obtained consisted preferably of 1,4-units and almost 100% of 1 ,4-units in the case of 1,3-cyclohexadiene. ESR measurements revealed that inclusion polymerization of cyclopentadiene or 1,3-cyclohexadiene in DCA canals proceeds by a free radical mechanism. ZUSAMMENFASSUNG:Mit Desoxycholslure (DCS) als Wirtskomponente wird die EinschluBpolymerisation von cyclischen Dienmonomeren wie Cyclopentadien, 1,3-Cyclohexadien, 1,3-Cycloheptadien, 1,5-Cyclooctadien und 2,5-Norbornadien untersucht. Die Bildung von Monomer-DCS-EinschluRverbindungen wurde beobachtet, aberPolymerisation setzte nur mit Cyclopentadien, 1,3-Cyclohexadien oder 1,3-Cycloheptadien ein. Die erhaltenen Polymeren bestanden hauptsachlich aus 1,4-Einheiten und fast zu 100% aus 1 ,CEinheiten im Fall des 1,3-Cyclohexadiens. ESR-Messungen zeigen, daB die EinschluBpolymerisation von Cyclopentadien oder 1,3-Cyclohexadien in DCS-Kanalen nach einem Radikal-Mechanismus ablauft .

Inclusion polymerization of 1‐chlorobutadiene in a deoxycholic acid canal

Tsutsumi

Okanishi

J. Polym. Sci. A Polym. Chem.

et al. 1990

Inclusion polymerization of 1‐chlorobutadiene was studied using 3α,12α‐dihydroxy‐5β‐cholan‐24‐oic acid (deoxycholic acid, DCA) as host molecules. It was found that the poly(1‐chlorobutadiene) had almost 100% of head to tail, trans‐1,4‐structure on the basis of 13C‐NMR and IR spectroscopies. This was the first example of preparing the highly regulated poly(1‐chlorobutadiene) by using the inclusion polymerization technique. The polymers obtained were optically active and the maximum value of specific rotation was [α]D‐41.9°. Both the rate constants and the value of activation energy of the elementary reactions of inclusion polymerization of 1‐chlorobutadiene were determined by graphical evaluation. The activation energy of propagation and termination was 11.7 and 11.1 kcal/mol, respectively.