The
merging of click chemistry with discrete photochemical processes
has led to the creation of a new class of click reactions, collectively
known as photoclick chemistry. These light-triggered click reactions
allow the synthesis of diverse organic structures in a rapid and precise
manner under mild conditions. Because light offers unparalleled spatiotemporal
control over the generation of the reactive intermediates, photoclick
chemistry has become an indispensable tool for a wide range of spatially
addressable applications including surface functionalization, polymer
conjugation and cross-linking, and biomolecular labeling in the native
cellular environment. Over the past decade, a growing number of photoclick
reactions have been developed, especially those based on the 1,3-dipolar
cycloadditions and Diels–Alder reactions owing to their excellent
reaction kinetics, selectivity, and biocompatibility. This review
summarizes the recent advances in the development of photoclick reactions
and their applications in chemical biology and materials science.
A particular emphasis is placed on the historical contexts and mechanistic
insights into each of the selected reactions. The in-depth discussion
presented here should stimulate further development of the field,
including the design of new photoactivation modalities, the continuous
expansion of λ-orthogonal tandem photoclick chemistry, and the
innovative use of these unique tools in bioconjugation and nanomaterial
synthesis.