Organotrifluoroborates: Another Branch of the Mighty Oak

Over the past two decades, organotrifluoroborates have evolved from being chemical curiosities to important reagents for the elaboration of organic molecules. Aside from their often-unique reactivity patterns, favorable features of these reagents include their ease of preparation/isolation, reliable crystallinity, enhanced stability, and monomeric structure. Currently >600 structurally diverse reagents of this class are commercially available, and >850 such compounds have been reported from the author's laboratory. The organotrifluoroborates can be utilized as shelf-stable precursors to a variety of end products through simple functional group transformations and have also been employed as partners in cross-coupling reactions between aromatic, alkenyl, alkynyl, and alkyl substrates in library or individual formats. Within the realm of cross-coupling reactions, organotrifluoroborates provide a practical entry to substructural entities not readily accessed using other organometallic reagents, and most recently, the development of a novel mechanistic paradigm for cross-coupling promises to expand the range of accessible cross-coupling partners even further to include both single- and two-electron processes.