C-H Arylation on Nickel Nanoparticles Monitored by In Situ Surface-Enhanced Raman Spectroscopy.

Bifunctional Au@Ni core-satellite nanostructures synthesized by a one-step assembly method were employed for in situ surface-enhanced Raman spectroscopic (SERS) monitoring of Ni-catalyzed C-C bond-forming reactions. Surprisingly, the reaction that was thought to be an Ullmann-type self-coupling reaction, was found to be a cross-coupling reaction proceeding by photoinduced aromatic C-H bond arylation. In situ SERS monitoring enabled the discovery, and a series of biphenyl compounds were synthesized photocatalytically, and at room temperature, using cheap Ni nanoparticle catalysts.