Solid-Phase Synthesis of Photochromic Spiropyrans

Significance

A 23-membered photochromic spiropyrans library was prepared via solid-phase synthesis. An indoline derivative was anchored onto the Wang resin by a succinate linker. Reaction of the supported indoline 1 with various salicylaldehydes 2 gave the corresponding resin-bound spiropyrans 3. The resin-bound spiropyrans were cleaved from solid phase with a catalytic amount of t-BuOK to afford excellent yields of succinimidospiropyrans (82-100%).