Sustainable, Oxidative, and Metal-Free Annulation

5 years ago

Sustainable, Oxidative, and Metal-Free Annulation

Luis Bering, Srimanta Manna, Andrey P. Antonchick

Annulation has received steadily growing interest in the interplay with the increasing emphasis towards selective C−H bond functionalization reactions. Metal-free oxidative annulation through functionalization of inert and abundant C−H bonds offers great improvements in terms of atom- and step-economics as well as reduced waste production under mild reaction conditions. Annulation is considered to be a highly efficient strategy for the construction of cyclic molecules because at least two new bonds are formed within a single reaction step. The combination of annulation and direct C−H bond functionalization allows the efficient and straightforward synthesis of carbo- and heterocyclic molecules using simple and non-prefunctionalized precursors. This Concept highlights novel strategies and recent breakthroughs for metal-free annulation through C−H bond functionalization giving access to a variety of important structural motifs. Annulating the competition: The combination of annulation strategies and direct C−H bond functionalization reactions allow the efficient synthesis of cyclic molecules using readily available and non-prefunctionalized precursors. Metal-free oxidative coupling through C−H bond functionalization is a green and sustainable approach because it is environmentally benign as well as both atom- and step-economical. This Concept highlights novel strategies and recent breakthroughs for metal-free annulation through C−H bond functionalization giving access to a variety of important structural motifs.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201702063