Inert C–H Bond Transformations Enabled by Organometallic Manganese Catalysis

ConspectusTraditional organic synthesis relies heavily on the transformations of various preinstalled functional groups, such as cross-coupling reactions using organohalides and organometallic reagents. The strategy of C–H activation enables the direct formation of C–C/C–X (X = heteroatom) bonds from inert C–H bonds, which can enhance the atom- and step-economy of organic synthesis. To date, precious metals have overwhelmingly dominated the C–H activation field; however, the rarity and high cost of these metals necessitate the development of more sustainable catalysts. In this regard, catalysts based on manganese are highly desirable owing to the abundant reserve of manganese in the earth’s crust and its economic benefits, low toxicity, and potentially unique reactivity. Although the first stoichiometric manganese-mediated C–H activation reaction was reported as early as 1970, manganese-catalyzed C–H activation reactions are largely underdeveloped. How to construct an efficient catalytic cycle for mangane...