Asymmetric Domino Reactions Based on the Use of Chiral Organocatalysts
The goal of this chapter is to cover the recent developments in enantioselective organocatalytic domino reactions, which have rapidly become a powerful, fascinating, and highly efficient tool in organic chemistry, and can be considered as one of the most influential reaction classes of the last century. The chapter is divided into two principal parts, dealing with one- and two-component domino reactions, and with multicomponent reactions, respectively. The first part is subdivided into two sections, describing domino reactions initiated by the Michael reaction, and other domino reactions, respectively. The second part is subdivided into nine sections, which deal respectively with multicomponent reactions initiated by the Michael reaction, multicomponent reactions initiated by the Knoevenagel reaction, multicomponent reactions based on the Mannich reaction, multicomponent reactions based on the Biginelli reaction, multicomponent reactions based on the Hantzsch reaction, multicomponent reactions based on the Strecker reaction, multicomponent reactions based on the Petasis reaction, 1,3-dipolar cycloaddition-based multicomponent reactions, and finally miscellaneous multicomponent reactions. This chapter demonstrates that the combination of asymmetric organocatalysis with the concept of domino sequences has allowed the easy attainment of high molecular complexity with very often excellent levels of stereocontrol in environmentally friendly conditions, avoiding metal contamination of the products, which is of great importance for future applications in the pharmaceutical industry.