Organic Chemistry Seminar

     In this presentation I will discuss two ongoing projects that focus on developing new synthetic organic methods for the preparation of nitrogen-containing heterocycles.  In the first portion of my talk I will describe our studies of the intramolecular reactivity of 1-aza-2-azoniaallene salts.  We have discovered that these somewhat esoteric heteroallene intermediates have a surprisingly diverse reactivity profile that can lead to the formation of several structurally-distinct and useful heterocyclic scaffolds.  In the second portion of my talk I will describe the development of a novel ring fragmentation / intramolecular azomethine ylide 1,3-dipolar cycloaddition reaction sequence that constitutes an efficient three-step route to polycyclic 2,5-dihydropyrroles from α-silyloxy ketones.  Recent applications of this reaction sequence in alkaloid natural product synthesis will also be described.