This minireview summarizes the research advances on selective remote C−H bond activation through 1,5-palladium migration. The background, reaction scope, mechanistic rationale of each transformation and an outlook of future direction of related field are included.

Abstract

“Through space” metal/hydrogen shift constitutes one of the efficient elementary step in organometallic chemistry to achieve selective remote C−H bond functionalization. Compared with the relatively extensive exploration on 1,4-palladium migration, the processes on corresponding 1,5-palladium translocation are far less explored. Based on our understanding on related research areas, we summarized the advances achieved in remote C−H bond activation through a key step of 1,5-palladium migration in this minireview. The background, reaction scope, and more importantly, the mechanistic rationale of each transformation was discussed. We hope by reading through this minireview, one could get a general perspective on direct C−H bond activation via 1,5-palladium/hydrogen shift, and could understand why such a process is less common when compared with the process going through 1,4-palladium/hydrogen migration, and eventually could be inspired to develop practical ways for the synthesis of valuable molecules, which could not be prepared easily through other traditional approaches.