Transition-Metal-Free Synthesis of Benzo-Fused Five- and Six-Membered Heterocycles Employing Arynes

A comprehensive overview of the synthesis of various benzo-fused five- and six-membered heterocyclic compounds utilizing a transition-metal-free approach employing arynes is the focal theme of this chapter. The synthesis of these heterocycles has been achieved under green and operationally simple procedures using a mild method for the generation of arynes by the fluoride-induced 1,2-elimination of 2-(trimethylsilyl)aryl triflates developed by Kobayashi and coworkers in 1983. Consequently, arynes have been employed for the construction of multisubstituted arenes of structural diversity and complexity. The versatile transition-metal-free applications of arynes include cycloaddition reactions, insertion reactions, and multicomponent reactions for the construction of various heterocycles.