Chapter 2: Base Catalysis in Nonasymmetric Synthesis

This chapter focuses on the use of achiral bases such as alkyl or aryl amines, pyridine/imidazole derivatives and amidines, isothioureas and guanidines to promote a variety of reactions such as acylations, aldols, cycloadditions and Baylis–Hillman reactions. The aim of this chapter is to show the possibilities of Lewis-base catalysed reactions for the synthesis of very interesting nonasymmetric compounds. It also includes recently developed reactions using proline (and other chiral bases) as catalysts for reactions, which produce achiral products. The last part of this chapter deals with the use of nitrogen-heterocyclic carbenes (NHC) as catalytic systems for the synthesis of nonchiral compounds.