Cyclometallation of Heterocycles: A Reliable Strategy for Selective Functionalization

Abstract

Heterocyclic compounds are of paramount importance in essentially all fields of chemistry and in our daily life. Therefore, the synthesis and modification of such compounds is a constantly expanding field in synthetic chemistry. Recent developments of functionalization of heterocycles by means of cyclometallation (also called chelation-assisted functionalization), both stoichiometric and catalytic, indicate that this strategy displays enormous potential. In particular, this method facilitates considerably the synthesis of functionalized heterocycles in a regioselective (site-selective) manner, and also provides novel types of synthetic transformations.

Keywords:

• chelation-assisted functionalization
• cyclometallation
• directing group
• functionalization
• heterocycle
• metallacycle
• palladium
• regioselectivity
• rhodium
• ruthenium

ACKNOWLEDGEMENTS

Funding by the Ministerio de Economia y Competitividad (Spain, Project CTQ2011-22589) and Gobierno de Aragón (Spain, group E97) is gratefully acknowledged. L. C. thanks Consejo Superior de Investigaciones Científicas (Spain) for a Juan de la Cierva contract.