Transition Metal-catalyzed Regioselective Direct C-H Arylations UsingQuinone Diazide as Arylating Agent: A Mini Review

Abstract: Quinone diazides are a class of diazo compounds, having a planar six-membered ring system with diazo, carbonyl and al-kene groups in conjugation. Earlier it was used in optical, electronic, polymer materials etc. In the last few years, various rearrangements reactions and insertion reactions were explored by these diazo compounds via the formation of metallo-carbenoids. Recently, it has been used to incorporate phenol moieties to hydrocarbons or arene/heteroarenes systems via transition metal-catalyzed C-H bond activation. The reactions proceed via C-H bond insertion or migratory insertion of metal-carbenes. In many cases, the site-selectivities were obtained by the guidance of various directing groups (remova-ble or non-removable). At the same time, several asymmetric approaches were also studied to incorporate phenol deriv-atives to arenes/heteroarenes furnishing compounds showing axial chirality with high stereoselectivity. In this review, we will mainly focus on directed regioselective arylation with quinone diazides under transition metal catalysis through C-H bond activation.