Cyano ester styrene

Bis(camphorquinone-a-dioximato)cobalt(II) (10) has been developed as a catalyst for enan-tioselective cyclopropanation reactions. It allows selective carbene transfer from diazoacetic esters to terminal C-C double bonds which are in conjugation with vinyl, aryl, alkoxycarbonyl or cyano groups, but not to alkyl-substituted alkenes, cycloalkenes, 1,3-dienes and al-lenes. The unusual chemoselectivity and some other experimental observations make the two mechanistic pathways proposed vide supra) questionable for these special carbene-transfer reactions. In contrast, the cobalt(II) complex 11 allows not only the cyclopropanation of styrene but also of oct-l-ene, a nonactivated alkene (ethyl diazoacetate, 35 °C, 3mol% of catalyst yield 50-60%). ... 

Further diverse systems have been developed and used in the investigation of intramolecular SET processes. These include styrene/amide-spacer/amine diads, 9-aminoacridine/polyether-spacer/benzoate ester diads, l-(4-cyano-phenyl)-4-(cyanomethylene)piperidine, 7i-donor/polyoxyethylene/Zn(II)por-phyrin/N,N -dimethyl-4,4 -bipyridinium systems, naphthalene/porphyrin/ quinone cyclophanes and their anthracene analogues, pyropheophytin-naphthoquinone diads, rigid donor/bridge/acceptor systems, anilide-substi-... 

In formations of ternary complexes, the acceptor vinyl compound must have a double bond conjugated to a cyano or to a carbonyl group. Such acceptors are acrylonitrile, methacrylonitrile, acrylic and methacrylic esters and acids, methyl vinyl ketone, acrylamide, etc. Donor monomers are styrene, a-methyl styrene, butadiene, 2-3-dimethyl butadiene, isoprene, chloroprene, etc. 

The types of compounds that can be polymerized readily by the radical-chain mechanism are the same types that easily undergo free-radical addition reactions. Alkenes with aryl, ester, nitrile, or halide substituent groups that can stabilize the intermediate radical are most susceptible to radical polymerization. Terminal alkenes are generally more reactive toward radical-chain polymerization than more highly substituted isomers. The dominant mode of addition in radical-chain polymerization is head-to-tail. The reason for this orientation is that each successive addition of monomer takes place in such a way that the most stable possible radical intermediate is formed. For example, the addition to styrene occurs to give the phenyl-substituted radical to acrylonitrile, to give the cyano-substituted radical ... 

Monomers with electron-rich double bonds produce one-to-one copolymers with monomers having electron-poor double bonds in reaction systems that also contain certain Lewis acids. These latter are halides or alkyl halides of nontransition metal elements, including AlCb, ZnCh, SnCL, BF3, AI(CH2CH3)Cl2, alkyl boron halides, and other compounds. The acceptor monomer generally has a cyano or carbonyl group conjugated to a vinyl double bond. Examples are acrylic and methacrylic acids and their esters, acrylonitrile, vinyl ketones, maleic anydride, fumaric esters, vinylidene cyanide, sulfur dioxide, and carbon monoxide. The variety of donor molecules is large and includes various olefins, styrene, isoprene, vinyl halides and esters, vinylidene halides, and allyl monomers [30]. 

Poly(methyl methacrylate co styrene) n Poly (2-propenoic acid, 2-cyano-, methyl ester-co-ethenyl benzene). 

---