Organic semiconductor photocatalyst can bifunctionalize arenes and heteroarenes

Two-for-one approach to photoredox In photoredox catalysis, an excited chromophore typically activates a single reactant either by oxidizing or reducing it. Ghosh et al. used a semiconductor catalyst to activate two reactants at once by quenching both an excited electron and the residual positive hole (see the Perspective by Swift). As such, two different reactive carbon or halide fragments could be appended to separate sites on an aryl ring. The catalyst also tolerated strong nucleophiles such as cyanide and could be recovered easily and reused. Science , this issue p. 360 ; see also p. 320