Development of efficient methods for metal-free C–H bond functionalization

Abstract

The development of novel and efficient methods for the transition metal-free functionalization of inert and abundant C–H bonds offers striking advantages in terms of step- and atom economy under environmentally benign reaction conditions. Metal-free reactions serve as environmentally friendly substitutes for cost intensive and harmful transition metal-catalyzed reactions. However, oxidative coupling reactions under metal-free conditions face some unsolved problems. High molecular weight oxidants, which are often used in stoichiometric amounts, lead to the undesired generation of large quantities of waste. Additionally, some organic oxidants are toxic, explosive or corrosive. Consequently, the development of catalytic and metal-free methods for the functionalization of C–H bonds attracted significant interest. With the aim to develop novel transition metal-free reactions and to address the aforementioned challenges, different synthetic methods have been established.