Supported Metal Single Atom Thermocatalysts for CC, CSi , and CB Bond–Forming (Coupling) Reactions and Biomedical Applications

Supported single metal atoms with catalytic activity (single-atom catalysts or SACs) have appeared in recent years as potential alternatives to current solid catalysts based on supported organometallic complexes, clusters, and nanoparticles, where the exposed catalytic metal atoms are completely maximized (one single atom, 100% exposition) and where the support not only stabilizes the single metal atom but also tunes the catalytic activity by intimate metal–support interactions. This catalyst design avoids additional ligands and unproductive metal atoms and gives access to infinite structural possibilities. This chapter will focus on the use of SACs for reactions of interest in relatively complex organic synthesis, a very recent topic with barely more than thirty reports in the literature. In particular, the chapter will go through the reported examples of SACs for three representative metal-catalyzed reactions in organic synthesis: the carbon–carbon cross-coupling reaction (CC bond formation), the hydrosilylation (CSi bond formation), and the hydroboration (CB bond formation) of alkene and alkynes. It will be shown here how SAC design allows obtaining extremely active catalysts, which often outperforms the state-of-the-art homogeneous ones, and paves the way for the future use of SACs in organic synthesis. Besides, the incipient use of SACs in biological applications will also be commented, which holds a huge potential in the next years not only for the use of single metal atom nanozymes but also for the direct use of SACs in therapeutic programs.