Metal-free catalytic C-H bond activation and borylation of heteroarenes

A metal-free catalyst born of frustration Boron (a Lewis acid) and nitrogen or phosphorus fragments (both Lewis bases) tend to pair up. Keeping them separated on opposite ends of the same molecule creates a “frustrated” Lewis pair. Such molecules can manifest powerful reactivity, such as scission of the hydrogen-hydrogen bond in H 2 . Légaré et al. now extend this reactivity to the cleavage of carbon-hydrogen bonds in heteroaromatic compounds such as furans and pyrroles (see the Perspective by Bose and Marder). Their frustrated Lewis pair complex catalyzed borylation of these compounds. The selectivity pattern of the reaction complemented that seen with the metal catalysts conventionally used. Science , this issue p. 513 ; see also p. 473