Green Oxidative Synthesis of Epoxides

Epoxides are strained three-membered heterocycles that have a high interest in organic synthesis because they exhibit a very versatile reactivity. This chapter focuses on epoxidation methodologies that employ O2 and H2O2 as oxidants and base metals as catalysts. Assessment of an epoxidation method requires the study of its performance against different olefins. It is well-known that the reactivity of the olefins and the stability of the resulting epoxides are highly dependent on the structure of the epoxide and olefin. Heterogeneous silver catalyzed epoxidation is the most notable example of catalytic epoxidation employing O2 as the single oxidant. Hydrogen peroxide is a convenient oxidant from an economical and environmental point of view. It is relatively cheap, and its only by-product is water. Hydrogen peroxide and O2 can be reliably and efficiently used as green oxidants with catalysts based in first row transition metal ions. The chapter discusses few examples describing the use of peracids.