p‐Anisil as a Versatile Catalyst for the E‐to‐Z Photoisomerization of Activated Alkenes – Application in Late‐Stage Modification of Drugs and Peptides

High‐throughput experimentation was employed to discover p‐Anisil as a highly effective and versatile catalysts for the E‐to‐Z photoisomerization of cinnamic acid derivatives and other activated alkenes. This new catalytic system tolerated a number of functional groups found in medicinal chemistry. The discovery enabled the preparation of previously unknown complex Z‐alkenes in two steps directly from drugs or peptides.