Styrene with 1,3-dioxolane

Rakova and Korotkov compared the rates of homopolymerization and copolymerization of styrene and butadiene [226], Styrene polymerizes very rapidly and butadiene slowly. Their copolymerization is slow at first, with preferential consumption of butadiene. When most of the butadiene is consumed, the reaction gradually accelerates yielding a product with a high styrene content. In the authors opinion, this is caused by selective solvation of the active centres by butadiene only after butadiene has polymerized, does styrene gain access to the centres [227], A similar behaviour was observed by Medvedev and his co-workes [228] and by many others. In our laboratory we observed this kind of behaviour in the cationic polymerization of trioxane with dioxolane. Although trioxane is polymerized much more rapidly than dioxolane, their copolymerization starts slowly, and is accelerated with progressing depletion of dioxolane from the monomer mixture [229],... 

The radical ring-opening elimination polymerization of 4-methylene-l,3-dioxolane stimulated us to construct a novel template polymerization (3). The concept is that polymers bear polymers. Polymer-supported monomer, which had a structure of 2,2-dipheny 1-4-methylene-1,3-dioxolane, reacted with radical species to afford polyketone and copolymer of styrene with vinylbenzophenone as newborn polymer and template, respectively (Figure 12). These polymers were easily separated by fractional precipitation without any particular chemical treatment after polymerization. On the other hand, common template polymerization requires annoying procedures for the separation of obtained polymers form template. On this point, our novel template polymerization system differs from conventional template polymerization. 

KAR KaragOz, M.H., Zorer, O.S., and liter, Z., Analysis of physical and thermodynainic properties of poly (2-phenyl-1,3 -dioxolane-4-yl-methyl-methacrylate-co-styrene) with inverse gas chromatography, Polym.-Plast. Technol. Eng., 45, 785, 2006. 

Very interesting results were published in respect of application of copolymers of 4-methylene-2-phenyl-2-(4-vinylphenyl)-l,3 dioxolane with styrene as a template ... 

The terpolymer of the radical ring-opening polymerization monomer, 5-methyl-ene-2-phenyl-l,3-dioxolan-4-one, (I), with styrene, and methyl methacrylate was also prepared. 

Some heterocyclic monomers may undergo random copolymerization with vinyl monomers. This is a case of cyclic acetals (e.g., 1,3-dioxolane) which forms the random copolymers with styrene [308,309] or isoprene [310], Apparently, the oxycarbenium ions, being in equilibrium with tertiary oxonium ions (cf., Section II.B.6.b), are reactive enough to add styrene ... 

Anhydrous RuCb catalyzes the reaction of epoxides with acetone (in acetone under reflux, 1.5-5 h) to give 1,3-dioxolanes [64]. The same catalyst, in the presence of ammonium thiocyanate, converts epoxides into thiiranes. The reaction takes place with inversion of configuration (R)-(-r)-styrene oxide was converted into (5)-(-)-sty-rene sulfide of 78 % optical purity [65]. This transformation is also mediated by catalytic amounts (2 %) of an Fe(III) pentafluorophenylporphyrin complex [66]. Chloro-hydrins are formed on treatment of epoxides with stoichiometric amounts of FeCl3 in ether [67]. 

Mg-Al oxides with a Mg/Al ratio of 5, calcined at 400 °C, are the most active catalysts for the reaction of CO2 and styrene oxide, and DMF is the best solvent. Using this Mg-Al oxide, various kinds of epoxides could be quantitatively converted into the corresponding cyclic carbonates. This addition reaction proceeds with retention of the stereochemistry of epoxides the reaction of CO2 with (R)- and (S j-benzyl glycidyl ether gave and ( Sj-4-(benzyloxymethyl)-l,3-dioxolane-2-one with >99% e.e., respectively. 

Since the 4-phenyl-2-methylene-l,3-dioxolane (XXl) underwent much more extensive ring opening than did the unsubstituted 2-methylene-l,3-dioxolane (I), it was reeisoned that a benzyl ketene acetal would be a more effective chain transfer agent than diethyl ketene acetal. Thus vhen methyl benzyl ketene acetal was used with styrene, a complete addition-elimination occurred to produce an oligomer of styrene. 

Asymmetric induction in the palladium-catalyzed hydroesterification of z-methylstyrene, styrene and other alkenes in the presence of ligands with rigid 5//-dibenzophospholyl units linked to chiral cyclobutane, dioxolane or cyclohexane skeletons (CBDBP, DIPHOL, CHDBP) is compared with the effect of the analogous diphenylphosphane ligands18 23. 

Limited information exists in the literature, however, on the homo- or copolymerization of vinyl ethylene carbonate, 1 (VEC or 4-ethenyl-l,3-dioxolane-2-one) for the preparation of cyclic carbonate functional polymers. A few comments regarding polymerization of VEC are given in an early patent [9], In the only reported study of the copolymerization behavior of VEC, Asahara, Seno, and Imai described the copolymerization of VEC with vinyl acetate, styrene, and maleic anhydride and determined reactivity ratios [10. Their results indicated that VEC would copolymerize well with vinyl acetate, but in copolymerizations with styrene, little VEC could be incorporated into the copolymer. VEC appeared to copolymerize with maleic anhydride, however the compositions of the copolymers was not reported. Our goal was to further explore the use of VEC in the synthesis of cyclic carbonate functional polymers. 

Based on Frechefs work [20], Luis and coworkers [21] studied the influence of the mode of preparation of the polystyrene backbone functionalized with TADDOL (a,a,a, a -tetraaryl-l,3-dioxolane-4,5-dimethanol) 2. This immobilized ligand was loaded with titanium on the topicity of an asymmetric transformation. Here, the Diels-Alder reaction of cyclopentadiene with 3-crotonyl-l,3-oxazolidin-2-one was chosen as a model reaction. The TADDOL ligands were incorporated into the polymeric backbone either by polymerization using functionalized styrene derivative 1 or by grafting and coupling of phenol 2 to Merrifield-type resins (Scheme 7). 

PBT (20-80)/PPE (15-50)/SEBS (5-25)/styrene-cyclic ortho ester copolymer (2-15) TSE at 270 °C/impact strength vs. blends with unfimctionalized PS/PS copolymer prepared using styrene and 4-methacryloyloxymethyl-2-methoxy-2-methyl-l,3-dioxolane, fm example Khouri 1993... 

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