Development of Catalytic Site‐Selective C−H Oxidation

Abstract Direct C−H bond oxygenation is a strong and useful tool for the construction of oxygen functional groups. After Chen and White's pioneering works, various non‐heme‐type iron and manganese complexes were introduced, leading to strong development in this area. However, for this method to become a truly useful tool for synthetic organic chemistry, it is necessary to make further efforts to improve site‐selectivity, and catalyst durability. Recently, we found that non‐heme‐type ruthenium complex cis ‐ 1 presents efficient catalysis in C(sp 3 )−H oxygenation under acidic conditions. cis ‐ 1 ‐catalysed C−H oxygenation can oxidize various substrates including highly complex natural compounds using hypervalent iodine reagents as a terminal oxidant. Moreover, the catalyst system can use almost stoichiometric water molecules as the oxygen source through reversible hydrolysis of PhI(OCOR) 2 . It is a strong tool for producing isotopic‐oxygen‐labelled compounds. Moreover, the environmentally friendly hydrogen peroxide can be used as a terminal oxidant under acidic conditions.