Creating a reactive enediyne by using visible light: Photocontrol of the Bergman cyclization

Abstract

(Chemical Equation Presented) Visible changes: Visible light is used to create an active enediyne for Bergman cyclization by taking advantage of a well-known molecular photoswitch. Only isomer 2 has the enediyne structure required to produce a diradical that can be trapped as compound 3. Isomer 2 is formed from the thermally stable isomer 1 by stimulating the ring-opening reaction with visible light. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.