A pH‐Triggered Polymer Degradation or Drug Delivery System by Light‐Mediated Cis / Trans Isomerization of o ‐Hydroxy Cinnamates

A new methodology for the pH‐triggered degradation of polymers or for the release of drugs under visible light irradiation based on the cyclization of ortho ‐hydroxy‐cinnamates ( o HC) to coumarins is described. The key o HC structural motif can be readily incorporated into the rational design of novel photocleavable polymers via click chemistry. This main‐chain moiety undergoes a fast photocleavage when irradiated with 455 nm light provided...