NHC‐based Photoswitches in Catalysis: Recent Developments and Challenges

Abstract

Using light as an external stimulus, photoswitchable catalysis offers the attractive opportunities to modulate the activity and selectivity of catalytic systems on demand and remotely, with high spatial and temporal precision. Consequently, the development of photoswitchable catalyst has attracted considerable attention from the chemist community in recent decades, leading to various photoresponsive species with diverse properties. Among these, only a few examples incorporate N‐heterocyclic carbenes (NHCs), despite their unique electronic and steric properties and their ubiquity in organic and organometallic catalysis. This review highlights recent advances in this emerging research area from the first reported species in 2009 to the present day, with particular emphasis on the synthesis of photoswitchable NHCs and their corresponding transition metal complexes for application in catalysis. Future perspectives in the field are also discussed.