Toward Chromoselective Transformations in Biological Systems: Perspectives and Challenges

Addressing small-molecule chromophores with bioactive properties has been established as an effective means of controlling biological systems for several decades. However, the complexity of in vitro and especially in vivo systems cannot be matched by a single wavelength of light (de)activating one kind of chromophore. Consequently, developing methods to combine and individually control multiple chromophores within the same system is of high importance. An increasing number of strategies have become available relying on the chromoselective transformation of small molecules. This article features the chromoselective control of photoswitches, photoclick chemistry, and photocages, and highlights perspectives and future challenges to be overcome in the context of biological systems.