Transition Metal-free Approaches to Biaryls

Biaryls are a key structural motif in compounds with various practical applications, ranging from pharmaceuticals to material science, including ligands for organic synthesis. Given the growing concern about the use of transition metal mediated synthetic strategies in terms of reaction condition mildness, reagents costs and toxicity, and purification of the products from metal traces, herein we review the transition metal-free approaches to biaryls, which can be divided into metal-free cross-coupling of aromatics and metal-free benzannulation of aryl-substituted chains