Photoactive Iminobismuthanes for Catalytic C–H Amination

High Resolution Image Download MS PowerPoint Slide Metal-nitrenoids are employed in the direct amination of ubiquitous carbon–hydrogen bonds. Traditionally, their synthetic utility has relied on the redox flexibility and the coordinative reactivity of the metal center, conferred by the d -orbitals. Here, we demonstrate that bismuth─a main-group element lacking accessible frontier d -orbitals─can nevertheless exhibit catalytic activity analogous to that of transition-metal systems. When an iminobismuthane is subjected to light irradiation, a ligand-to-ligand charge transfer ensues, leading to C–H bond abstraction and C–N bond formation. The unique electronic properties of bismuth permit complementary reactivity beyond that of transition metals, as exemplified by the azidation of unprotected secondary amines. This work reveals main-group imidos as catalytically competent species, rather than merely precursors in transition-metal catalysis.