Synthesis of Nitrogen Heterocycles by Hypervalent Iodine Mediated Cyclization
This thesis discusses the synthesis of 3-arylpyrrolidin-2-ones and the use of hypervalent iodine reagents in organic synthesis.
With that being the case, the first chapter provides a brief introduction to nitrogen heterocycles and discusses methods for the synthesis of 3-arylpyrrolidin-2-ones. The second chapter provides an introduction to the bonding and reactivity of hypervalent iodine reagents. The third chapter explores the prior applications of hypervalent iodine reagent in organic synthesis with a focus on areas relevant to this work. This includes the use of hypervalent iodine reagents in the functionalization of alkynes, in nitrogen heterocycle synthesis and in various migratory reactions.
The fourth chapter discusses the results of an investigation into the synthesis of pyrrolidinones. A novel synthesis of 3-arylpyrrolidin-2-ones by a hypervalent iodine induced cyclization-rearrangement cascade reaction is reported. Starting from N-(4-arylbut-3-yn-1-yl)tosylamides, the initial cyclization gives an intermediary β-arylvinyl(phenyl)iodonium salt which has been isolated and characterized by NMR spectroscopy. Hydration of this intermediate leads to the generation of 3-arylpyrrolidin-2-ones by a 1,2-aryl shift with expulsion of iodobenzene.
The fifth chapter summarizes the results and suggests some avenues for future research. The final chapter provides the experimental details and characterization data for compounds isolated during the course of this work.