Total Synthesis and Structural Revision of the Piperarborenines: When Photochemistry Meets CH Activation

Activate and reiterate: The activation of C(sp3)H bonds is a highly desirable transformation because molecular complexity can be increased at the expense of the most simple and readily available organic linkage. In recent contributions this approach was used for coupling reactions with small all-carbon rings, as exemplified by the sequential CH activation steps in an elegant total synthesis of the piperarborenines (see scheme; DG=directing group).