Recent Advances in Radical-Mediated C-C Bond Fragmentation of Non-Strained Molecules

The carbon-carbon (C-C) sigma-bonds construct the fundamental frameworks of organic molecules. The direct functionalization of C-C bonds represents one of the most efficient and step-economical transformations in synthetic chemistry. The past few decades have witnessed the fast development of transition-metal mediated C-C bond activation. In contrast, the radical-promoted C-C bond cleavage has received relatively less attention. As the occurrence of ring strain significantly facilitates the fission of cyclic C-C bonds via radical approaches, the strain relief-driven C-C bond activation mostly relies on the three- and four-membered rings. The C-C activation of non-strained molecules such as medium- or large-sized rings and linear alkanes remains challenging. In this review, we will focus on the recent advances in radical-mediated C-C bond activation of non-strained molecules. Herein, the alkoxy- and iminyl-radical triggered scission of non-strained C-C bonds and C-C cleavage via the strategy of remote functional group migration is summarized.