Chapter 3: Homogeneous Acid Catalysis in Nonasymmetric Synthesis

Homogeneous acid catalysis of nonasymmetric reactions continues to be an area of significant focus, and this chapter concentrates on recent relevant advances within a green chemistry context. The developments in acid catalysis are viewed through a number of key reactions including esterification, hydrolysis, and etherification. We begin with an overview of the typical mechanistic considerations for acid catalysis. One of the key, recent developments in the area has been a drive towards the application of novel “greener” solvent media for many classical acid-catalysed transformations. We consider the benefits offered by “green” solvents such as high temperature and supercritical water, and ionic liquids, on acid-catalysed reactions. We also briefly overview other recent advances including acid-catalysed biomass conversion and direct esterifications. Emphasis is placed throughout on the insight provided through mechanistic studies, and differences to analogous reactions in conventional aqueous media.