Diazo Quinone: An Effective Phenolic Precursor for Building C(sp²)−C(sp²) Bonds

Abstract

Phenolic biaryl and styryl moieties are important structural motifs in natural products, pharmaceuticals, and functional materials. Traditional cross‐coupling often requires prefunctional substrates and is accompanied by generation of organometallic by‐products. In recent years, diazo quinone has become a new type of high‐efficiency phenolic coupling reagent for the preparation of phenolic biaryl and styryl compounds. This is because it can be used to construct C(sp2)–C(sp2) bonds in an environment‐friendly (transition‐metal‐free) or more direct way. In this review, we focus on recent advances in the field of transitionmetal‐free cross‐coupling reactions of diazo quinones with organoboranes and transition‐metal catalyzed quinoid carbene C(sp2)–H arylation reactions.