Adventures in polyene chemistry

This thesis focuses on the development of new and efficient ways to synthesise diverse families of compounds containing different numbers of alkenes in conjugation. These new approaches involve sequences of cross-coupling reactions. Explorations into the chemical reactivity of these compounds have also been carried out. Chapter 1 is a review of the literature of multi C(sp2)-C(sp2) bond couplings involving alkene reaction partners. Chapter 2 explores the synthesis of dendralenes and certain allenic congeners through a new and efficient cross-coupling protocol. Chapter 3 describes how these novel oligo-alkenes can be used to form multi-cyclic frameworks in an efficient manner. The focus of Chapter 4 is the fundamental hydrocarbon tetravinylethylene and its substituted analogues. Many reviews have been written on cross-coupling chemistry but none survey the literature of one pot, multi C(sp2)-C(sp2) bond couplings involving alkene reaction partners. Chapter 1 is a comprehensive review of the published work in this field. Specifically, this review covers published examples of one pot, 2-, 3- and 4-fold cross-coupling reactions between alkenic nucleophiles and alkenic electrophiles. A new variation on the cross-coupling theme is described in Chapter 2. This one pot, double cross-coupling sequence allows the synthesis of the fundamental hydrocarbon [6]dendralene in greater than ten gram scale. It is also demonstrated that this new synthetic technology allows rapid access to previously inaccessible structures including certain substituted [4]dendralenes and 1-substituted 1-(2'-(1',3'-butadienyl))allenes. Chapter 3 describes the results of an investigation into the reactivity of these novel dendralenes in Diels-Alder reactions with a dienophile. This study reveals the first chemoselective Diels-Alder reactions of [4]dendralenes that led to the isolation of [3]dendralenes. The results of the first study of Diels-Alder reactions of 1-substituted 1-(2'-(1',3'-butadienyl))allenes is also reported in this Chapter. The work in Chapter 4 describes a new synthesis of tetravinylethylene. The synthesis allows a multigram scale preparation of the hydrocarbon through a one pot, 4-fold Stille cross-coupling between the commercially available starting materials tetrachloroethylene and tributyl(vinyl) stannane. This approach also allows access to a variety of substituted tetravinylethylenes and, as such, represents the first general method of preparation for this family. Tetravinylethylene is smoothly converted into 2,3-divinyl-1,3-cyclohexadiene, which reacts with the dienophile N-methylmaleimide to give single, double or triple Diels-Alder adducts in a selective manner. All three Diels-Alder adducts can also be accessed in one pot starting from tetravinylethylene.

Author dc:creator

• Lindeboom, Erik

Statement dc:rights

• Author retains copyright

Language dc:language.iso

en_AU

Dc Identifier Other

b3579036

OAI identifier oai:identifier

oai:openresearch-repository.anu.edu.au:1885/151541