Studies On Construction Of Heterocycles From Benzyl Azides

Development of efficient, practical, and environmentally benign synthetic methods for constructing structurally complex scaffolds continues to attract the attention of synthetic chemists. Thus, cascade reactions, which involve multi-step transformations in a one-pot fashion to convert readily available reactants into complex molecular architectures, have become particularly powerful and attractive in modern synthetic chemistry. Because of their unique chemical properties, azides have attracted the interest of chemists for a long time. They are widely used in organic synthesis.The thesis mainly includes two parts. The first part breifly reviews the properties of azides and their applications in the synthesis of heterocycles. The second part describes a new method to construct tetrahydro-5H-indolo[3,2-c]quinolines from benzyl azides and indoles via a formal [4+2] cycloaddition that involved an in situ generated iminium ion. It features mild conditions and a broad substrate scope and holds great potential in constructing polycyclic indolines with tertiary and/or quaternary carbon centers that are widely present in the complex indoline alkaloids. The method not only applies to indoles but also to other related substrates.