Lewis acid catalysis for (2+2)-cycloadditions and alternating copolymerizations.

Persistent Link:
http://hdl.handle.net/10150/186133
Title:
Lewis acid catalysis for (2+2)-cycloadditions and alternating copolymerizations.
Author:
Srisiri, Warunee.
Issue Date:
1993
Publisher:
The University of Arizona.
Rights:
Copyright © 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.
Abstract:
(2+2) -Cycloaddition reactions between alkenes take place spontaneously when one alkene contains strong donors and the other strong acceptors. However, when the difference of electron-density between these nucleophilic and electrophilic partners is small, the (2+2) -cycloaddition does not take place. Lewis acids are known as catalysts for many purposes due to their capability to increase the accepting ability of an electrophile, and can be utilized as catalysts for these (2+2) -cycloadditions. In this study, it is shown that ethereal lithium perchlorate, which has recently been recognized as an astounding medium for many reactions, and zinc chloride can promote (2+2) -cycloadditions. This systematic study of the (2+2) -cycloadditions between various nucleophiles and electrophiles leads to an expansion of "The Organic Chemist's Periodic Table". When the electrophilic partner contains at least one ester at the olefinic end, the (2+2) -cycloaddition can occur in the presence of Lewis acid, instead of the reported inverse electron demand Diels-Alder reaction. The efficiency of Lewis acid catalysis to promote (2+2) -cycloadditions for olefin pairs where they normally do not occur is investigated. Weak Lewis acids are suitable for the (2+2) -cycloaddition in contrast to strong Lewis acids, which cause decomposition of the cyclobutanes. In addition, many cyclobutane derivatives containing an acidic proton at C₃ and a leaving group derived from sulfide at C₁ are synthesized. However, the aim of obtaining bicyclobutane by 1,3-elimination of these cyclobutane derivatives was not achieved. An exploratory study using zinc chloride as Lewis acid to promote the spontaneous alternating copolymerization between the weak acceptor olefin acrylonitrile and the donor olefins, p-methylstyrene, p-methoxystyrene and isobutyl vinyl ether was also performed.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Dissertations, Academic.; Chemistry, Organic.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Hall, H.K., Jr.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleLewis acid catalysis for (2+2)-cycloadditions and alternating copolymerizations.en_US
dc.creatorSrisiri, Warunee.en_US
dc.contributor.authorSrisiri, Warunee.en_US
dc.date.issued1993en_US
dc.publisherThe University of Arizona.en_US
dc.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.en_US
dc.description.abstract(2+2) -Cycloaddition reactions between alkenes take place spontaneously when one alkene contains strong donors and the other strong acceptors. However, when the difference of electron-density between these nucleophilic and electrophilic partners is small, the (2+2) -cycloaddition does not take place. Lewis acids are known as catalysts for many purposes due to their capability to increase the accepting ability of an electrophile, and can be utilized as catalysts for these (2+2) -cycloadditions. In this study, it is shown that ethereal lithium perchlorate, which has recently been recognized as an astounding medium for many reactions, and zinc chloride can promote (2+2) -cycloadditions. This systematic study of the (2+2) -cycloadditions between various nucleophiles and electrophiles leads to an expansion of "The Organic Chemist's Periodic Table". When the electrophilic partner contains at least one ester at the olefinic end, the (2+2) -cycloaddition can occur in the presence of Lewis acid, instead of the reported inverse electron demand Diels-Alder reaction. The efficiency of Lewis acid catalysis to promote (2+2) -cycloadditions for olefin pairs where they normally do not occur is investigated. Weak Lewis acids are suitable for the (2+2) -cycloaddition in contrast to strong Lewis acids, which cause decomposition of the cyclobutanes. In addition, many cyclobutane derivatives containing an acidic proton at C₃ and a leaving group derived from sulfide at C₁ are synthesized. However, the aim of obtaining bicyclobutane by 1,3-elimination of these cyclobutane derivatives was not achieved. An exploratory study using zinc chloride as Lewis acid to promote the spontaneous alternating copolymerization between the weak acceptor olefin acrylonitrile and the donor olefins, p-methylstyrene, p-methoxystyrene and isobutyl vinyl ether was also performed.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectDissertations, Academic.en_US
dc.subjectChemistry, Organic.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairHall, H.K., Jr.en_US
dc.contributor.committeememberBates, R.B.en_US
dc.contributor.committeememberGlass, R.S.en_US
dc.contributor.committeememberRund, Johnen_US
dc.contributor.committeememberWalker, F. Annen_US
dc.identifier.proquest9322634en_US
dc.identifier.oclc715358852en_US
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