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Advances on Directing-Group Assisted meta-C-H Functionalization Catalyzed by Transition Metal

Transition-metal-catalyzed functionalization of unactivated C — H bonds is a highly attractive strategy for the syn-thesis of organic molecules, however, regioselective control is a central challenge in this field. The directing group assisted C — H functionalizations such as the use of directing templates and transient mediator, secondary interaction have attracted more attentions from researchers. The meta -C — H functionalizatioin assisted by directing groups are summarized in details. The existing problems and limitations of this field are also included. Finally, the development trend of this area is prospected.