Synthesis of securingine B enables photoresponsive materials design

Abstract

In general, natural products exist in their most thermodynamically stable form. Therefore, final stage-reaction conditions leading to thermodynamic equilibrium often facilitate the production of the desired natural products. On the other hand, syntheses of contra-thermodynamic natural products pose greater challenges, as the thermodynamic bias should be overcome. Herein, we present the synthesis of contra-thermodynamic securinega alkaloid securingine B, derived from the more thermodynamically stable isomer secu’amamine D. Harnessing the disparity in triplet energy between two natural products, we have established a photochemical equilibrium favoring securingine B. Conversely, secu’amamine D was reformed from securingine B under thermodynamic equilibrium conditions. Inspired by these observations, we devised a novel type of photoswitching platform by introducing a push-pull system to the securinega framework. By leveraging this new photoswitching scaffold, we have developed a securingine B-inspired photochromic material and, subsequently, exploited it as a photoresponsive chiral dopant.