UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Syntheses of chlorin, benzoporphyrin and bacteriochlorin derivatives Yon-Hin, Paul

Abstract

The syntheses of chlorin, benzoporphyrin, and bacteriochlorin derivatives are presented in this thesis. The key step in each synthesis involved a Diels-Alder reaction of a vinylporphyrin with an appropriate dienophile. The vinylporphyrins 81,101 and 106 were prepared in high yield using a variation of Johnson's regioselective synthesis employing dipyrromethenes 93,94,104, and 144 as crucial building blocks. As the first objective, the Diels-Alder reactions of 81 with 1,2-disubstituted vinyl sulfones were investigated in order to provide a route to chlorin derivatives which could act as intermediates in a proposed synthetic pathway for a model compound of factor 1. The regio-and stereoselectivity of the cycloadditions were examined and the appropriate regioisomers were considered for the continuation of the proposed synthetic plan. The second objective of the work was to provide a general strategy directed towards the synthesis of benzoporphyrin derivatives via a common intermediate, namely the β-unsubstituted-β'-vinylporphyrin 101. Evidence is presented that suggests an isomerization of the initial cycloadduct to another porphyrin en route to the benzoporphyrin 171. The final objective of the work was to synthesize stable bacteriochlorin derivatives to be used as photosensitizers in photodynamic therapy. The key intermediate, an A,C-divinylporphyrin 106, was synthesized via two routes, and its chemistry with olefinic and acetylenic dienophiles was studied. The resulting bis-adducts (e.g. 179 and 183) were isolated in moderate yields and were found to be stable compounds absorbing light in the 730-800 nm region.[See Thesis for Diagrams]

Item Media

Item Citations and Data

Rights

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.