Double C–H amination The conversion of C–H bonds into C–N bonds is broadly useful in producing pharmaceutically important compounds from simple, readily available feedstocks. Shen and Lambert report a method to induce this reaction twice in a row at benzylic and neighboring alkyl carbon centers, using acetonitrile solvent as a convenient source of nitrogen. The method relies on successive electrochemical and photochemical activation of a cyclopropenium catalyst and yields hydrogen gas as a clean co-product. Science , this issue p. 620