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The direct functionalization of quinones has always fascinated research communities due to their biological and redox activities and subsequent application. Quinone motifs play a vital role as precursors for many bioactive compounds and materials; hence, many ingenious methodologies have been elaborated for exploring these units. A significant part of the synthetic strategies towards the functionalized quinones has been achieved by installing substituents on hydroquinones, phenols, or quinone itself by different oxidative coupling reactions via radical pathways with or without the utilization of metal catalysts. The functionalization of simple quinones via direct C−H bond remains challenging due to their inherited electronic nature and high bond dissociation energy. This review article summarizes the recent advancement made for functionalized quinones through direct functionalization of simple quinones. Our primary focus will be on the synthetic approaches and mechanistic pathways of these reactions that have appeared in the last two decades, along with a short historical importance of the quinone family. [ABSTRACT FROM AUTHOR]

Site‐selective C(sp3)−H functionalization of unreactive hydrocarbons is always challenging due to its inherited chemical inertness, slightly different reactivity of various C−H bonds, and intrinsically high bond dissociation energies. Here, a site‐selective C−H alkylation of naphthoquinone with unactivated hydrocarbons using Mn2(CO)10 as a catalyst under blue‐light (457 nm) irradiation without any external acid or base and pre‐functionalization is presented. The selective C−H functionalization of tertiary over secondary and secondary over primary C(sp3)−H bonds in abundant chemical feedstocks was achieved, and hydroxylation of quinones was realized in situ by employing the developed methodology. This protocol provides a new catalytic system for the direct construction of high‐value‐added compounds, namely, parvaquone (a commercially available drug used to treat theileriosis) and its derivatives under ambient reaction conditions. Moreover, this operationally simple protocol applies to various linear‐, branched‐, and cyclo‐alkanes with high degrees of site selectivity under blue‐light irradiated conditions and could provide rapid and straightforward access to versatile methodologies for upgrading feedstock chemicals. Mechanistic insight by radical trapping, radical scavenging, EPR, and other controlled experiments well corroborated with DFT studies suggest that the reaction proceeds by a radical pathway. [ABSTRACT FROM AUTHOR]

The Front Cover highlights how the direct functionalization of quinones has always fascinated research communities due to their biological and redox activities and subsequent application. In their Review (DOI: 10.1002/ejoc.202400535), R. Kumar Jha and S. Kumar have brought together the historical importance of and the recent advancements made towards the direct functionalization of quinones for the construction valuable functionalized quinones. Most of the synthesized quinone derivatives have applications in biological activities, flow batteries and catalysis...By Raushan Kumar Jha and Sangit KumarReported by Author; Author [Extracted from the article]

Site-selective C(sp 3 )-H functionalization of unreactive hydrocarbons is always challenging due to its inherited chemical inertness, slightly different reactivity of various C-H bonds, and intrinsically high bond dissociation energies. Here, a site-selective C-H alkylation of naphthoquinone with unactivated hydrocarbons using Mn 2 (CO) 10 as a catalyst under blue-light (457 nm) irradiation without any external acid or base and pre-functionalization is presented. The selective C-H functionalization of tertiary over secondary and secondary over primary C(sp 3 )-H bonds in abundant chemical feedstocks was achieved, and hydroxylation of quinones was realized in situ by employing the developed methodology. This protocol provides a new catalytic system for the direct construction of high-value-added compounds, namely, parvaquone (a commercially available drug used to treat theileriosis) and its derivatives under ambient reaction conditions. Moreover, this operationally simple protocol applies to various linear-, branched-, and cyclo-alkanes with high degrees of site selectivity under blue-light irradiated conditions and could provide rapid and straightforward access to versatile methodologies for upgrading feedstock chemicals. Mechanistic insight by radical trapping, radical scavenging, EPR, and other controlled experiments well corroborated with DFT studies suggest that the reaction proceeds by a radical pathway., (© 2023 Wiley-VCH GmbH.)