Photochemical cycloaromatization reactions of ortho-dialkynylarenes: A new class of DNA photocleaving agents

We are intrigued by the possibility of consolidating the functional elements of the enediyne anticancer antibiotics, thereby simplifying the task of synthesizing potential chemotherapeutic agents which operate by DNA cleavage pathways. Thus, it was envisaged that certain polycyclic ortho-dialkynylarenes would intercalate into DNA and, moreover, the planar π systems might be further exploited by facilitating photochemical, as opposed to thermal, cycloaromatization/cleavage reactions. We report herein on the viability of this photochemical transformation and the resultant new class of DNA photocleaving agents, whose binding and photoactive domains are consolidated, and which generate two reactive sites for subsequent ribose hydrogen atom abstraction(s).