Water‐compatible Chiral Lewis Acids

This chapter highlights the water-compatible chiral Lewis acid catalysts that emphasize their usefulness and potential application in next-generation organic synthesis and may result in the development of novel modes of chemical transformations. Lewis acid catalysis has received much attention in organic synthesis as it often affords access to rate enhancement and chiral induction under mild conditions. The development of asymmetric Mukaiyama aldol reactions in aqueous environments epitomizes the history of the development of water-compatible chiral Lewis acid catalysts. The aldol reaction based on the use of preformed metal enolates provides one of the most fundamental and reliable methods for stereoselective CC bond formation in organic chemistry. To control the absolute configuration of the desired product in Diels-Alder reactions, enantioselective Lewis acid catalysis has been studied extensively through a chiral Lewis acid-dienophile (OC) coordination. It serves as the activation process and defines the structure and concentration of a chiral Lewis acid-dienophile complex in equilibrium.