Catalytic Aromatic CH Functionalization Involving Metal Carbene

Abstract The metal carbene species, which catalytically generated from diazo compounds or other types of precursors, is one of the reactive and versatile synthons that possess broad applications in modern synthetic chemistry. A variety of reactions involving metal carbene have been well documented and reviewed, for example the metal carbene CH insertion reaction has become a very attractive and promising method for the expeditious construction of molecules with structural complexity. Whereas, reviews that focused on the catalytic aromatic CH functionalization using metal carbene, which went through a nondirected CH functionalization, are rare. This reaction has attracted considerable interest because of its ability for the direct CC bond formation with no need for prefunctionalization, providing a powerful and efficient tool in organic synthesis for rapid assembly of important molecules with structural diversity. The advances of catalytic aromatic CH functionalization using metal carbene in the last five decades using a variety of carbene precursors in the presence of different catalysts (or catalytic conditions), and the versatility of this method for the preparation of bioactive molecules, will be outlined in this article.