Exchanging Alkyl Groups through Unstrained C-C Bond Cleavage in the Presence of a Copper Catalyst.

Although numerous reports exist on strained C-C bond cleavage reactions in aryl substitutions, the cleavage methodology for unstrained C-C bonds in alkylation reactions has not yet been established. We found that unstrained allylic C-C bonds can be cleaved using α-radicals to form C(sp3 )-C(sp3 ) bonds in the presence of a copper catalyst. In this reaction, the property of leaving and loading radicals is very important for radical fragmentations. In this paper, we investigated the effects of these properties in cleavage reactions for unstrained C-C bonds.