Chapter 12 Ring rearrangement metathesis (RRM) — A new concept in piperidine and pyrrolidine synthesis

Abstract

This chapter focuses on the application of ruthenium-catalyzed olefin metathesis to the synthesis of piperidine and pyrrolidine containing compounds. Olefin metathesis has proved to be a powerful synthetic tool in organic synthesis. The advent of well-defined metal carbene complexes with remarkable functional group tolerance has rendered metathesis as an efficient route to the synthesis of new C–C bonds. Aside from polymerization reactions, olefin metathesis can be classified into three categories: ring-closing metathesis (RCM), ring-opening metathesis (ROM), and cross metathesis (CM). In classical organic synthesis, the individual bonds in the target molecule are usually formed step by step. Starting from relatively simple starting compounds, the structural complexity in the molecule slowly increases in the course of the synthesis. Domino, or tandem, reactions are processes that involve at least two transformations in one step, in which the subsequent reaction always occurs at the functionality formed in the previous step. These transformations can be either bond formation or bond cleavage. For example, linking several metathesis reactions allows for the rapid construction of complex structures from simple precursors in only one pot. Domino metathesis reactions of this type can be referred to as “ring rearrangement metathesis” (RRM).