Recent Applications of Imines as Key Intermediates in the Synthesis of Alkaloids and Novel Nitrogen Heterocycles

One of the major challenges in contemporary synthetic organic chemistry is the design and development of new tactics and strategies and their application to concise and efficient syntheses of biologically active natural products. Strategies that utilize reactions that enable the rapid assembly of the skeletal framework of such targets are thus especially attractive. In this context, we have developed novel applications of imine chemistry in Mannich and related reactions, cascade processes, and multicomponent reactions to rapidly assemble structural subunits common to diverse families of alkaloids. The practical utility of these chemistries is evidenced by their use in the execution of facile total syntheses of (±)-epilupinine (1), (±)-tashiromine (2), (-)-epimyrtine (3), and (±)-roelactamine (4) as well as other nitrogen heterocycles of potential biological interest.