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TETRAMETHYLENE INTERMEDIATES IN POLYMERIZATION AND CYCLOADDITION REACTIONS

Five tri- and tetra-substituted electron-poor olefins containing a β-leaving group, initiated cationic polymerization of p-methoxystyrene with widely varying results. As the electrophilicity of the electron-poor olefins increased, the yields and molecular weights of the polymers formed decreased. The same was true when the excellent leaving group, trifluoromethanesulfonate, was replaced by the poorer leaving group, chloride. Another series of tri-substituted olefins was prepared and reacted with p-methoxystyrene in the presence of excess methyl methacrylate or styrene. Terpolymer was formed as a major product when the electron-poor olefin used contained an α-ester group. The yield of the terpolymer increased with the increasing electrophilicity of the electron-poor olefin. The reactions of methyl α-cyanoacrylate with a number of electron-rich olefins were also studied and found to give new types of adducts, such as Diels-Alder adducts and pyrans. All these reactions were suggested to go through the formation of a tetramethylene intermediate, a resonance hybrid of a zwitterion and spin paired biradical.

Identiferoai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/281942
Date January 1981
CreatorsRasoul, Husam Ali Abdul
ContributorsHall, H. K. Jr.
PublisherThe University of Arizona.
Source SetsUniversity of Arizona
Languageen_US
Detected LanguageEnglish
Typetext, Dissertation-Reproduction (electronic)
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

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