Following the pioneering examples of Scholz [6] and Martin [7] in 1967, the photocyclization of stilbene derivatives under UV-light irradiation is now a classical method for the synthesis of phenanthrenes and helicene-like molecules [8]. However, the scalability of these reactions is limited by the required low concentration (~10 −3 mol·L −1 ) and usually long reaction times (>20 h). Therefore, most of the applications of this method are limited to small scale (<0.5 ...