Recent Advances in Using Transition-Metal-Catalyzed C–H Functionalization to Build Fluorescent Materials

Organic fluorescent molecules have broad applications in modern technology, such as in security systems, chemosensors, bioprobes, field-effect transistors, memory devices, organic light-emitting diodes, etc. The transition-metal-catalyzed C–H bond functionalization approach represents a distinct, facile, and atom-efficient tactic for the construction of organic fluorescent molecules, which are often difficult to prepare using typical synthetic methods. In this review, four types of C–H bond functionalization reactions for the preparation of fluorescent materials are discussed: (1) transition-metal-catalyzed C–H/C–X cross-coupling reactions; (2) transition-metal-catalyzed C–H/C–H cross-coupling reactions; (3) transition-metal-catalyzed C–H addition and/or annulation reactions; and (4) transition-metal-catalyzed C–H/C–M or C–H/Het-H bond functionalization. The objective of this review is to characterize the current state of the art in using transition-metal-catalyzed C–H functionalization to build fluorescent molecules as well as their application in electroluminescent materials, mechanofluorochromic materials, labels, sensors for bioimaging, etc.