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) transitionmetal-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.