In the past decade, transition-metal-catalyzed C–H activations have been very popular in the research field of organometallic chemistry, and have been considered as efficient and convenient strategies to afford complex natural products, functional advanced materials, fluorescent compounds, and pharmaceutical compounds. In this account, we begin with a brief introduction to the development of transition-metal-catalyzed C–H activation, especially the development of transition-metal-catalyzed chelation-assisted C–H activation. Then, a more detailed discussion is directed towards our recent studies on the transition-metal-catalyzed chelation-assisted oxidative C–H/C–H functionalization of aromatic substrates bearing directing functional groups.

A metal-free, efficient, practical, and convenient process based on an iodine-catalyzed oxidative cleavage reaction has been developed to form 1,2-diaryldiketons in high yields from 1,3-diaryldiketones. The reaction is performed in DMSO and in air, and a mechanism was proposed according to the reaction evidence.

An efficient and clean method to construct CC bonds has been developed via the acylation reaction of acetanilides with benzylic alcohols using tert-butyl hydroperoxide (TBHP) as oxidant catalyzed by palladium acetate in the presence of triflic acid (TfOH). The acylation reactions exhibit excellent reactivities, and up to 95% yield of the corresponding aryl ketone could be obtained under the optimal conditions.

Quaternary ammonium iodide, a metal-free and mild catalyst, was proven to be a successful catalyst in the oxidative cleavage of 1,3-dicarbonyl derivatives with H₂O₂ as terminal oxidant. The mechanistic aspects of these “multistep” catalytic oxidations were discussed in terms of the catalytic cycle of the iodine species and the oxidative cleavage of the α carbon from the dicarbonyl compounds to generate the corresponding carboxylic acids.

An efficient tandem cross-coupling reaction of o-chlorobenzoyl chloride with dialkyl and diaryl magnesium compounds in the presence of manganese (II) chloride was developed, which proceeds in good yield under mild conditions. Copyright © 2009 John Wiley & Sons, Ltd.

Iron trichloride hexahydrate has proved to be a very effective catalyst for the three-component condensation of aromatic aldehydes, amines and allyltributylstannane, which produces high yields of homoallylic amines in water in the presence of surfactant SDS. Copyright © 2009 John Wiley & Sons, Ltd.

A new efficient homocoupling reaction was reported in one pot by a combination of metallic magnesium and a catalytic amount of manganese (II) chloride. Various aromatic and alkyl halides underwent homocoupling smoothly, affording the corresponding symmetrical homocoupling compounds in moderate to good yields. The readily available MnCl₂, the mild reaction conditions and the operational simplicity and practicability allow for an easy and practical procedure for the purpose of carboncarbon bond formation. Copyright © 2007 John Wiley & Sons, Ltd.