Enantioselective Transformation of Hydrazones via\nRemote NHC Catalysis: Activation Across CN and N–N\nBonds

The\ncatalytic asymmetric transformation of nitrogen atoms to prepare\nheterocyclic molecules is of significant value in organic synthesis\nand biological applications. Here, we disclose the activation of the\nnitrogen atom in hydrazine-derived hydrazone via an <i>N</i>-heterocyclic carbene (NHC) organic catalyst for highly enantioselective\nformal cycloaddition reactions. The range of NHC catalysis extends\nacross several (carbon and hetero) atoms and diverse chemical bonds\n(CN and N–N bonds) to activate nitrogen atoms at remote\nsites with excellent reactivity and (stereo)selectivity control. Our\nstrategy for nitrogen atom activation, along with the NHC-bound diaza-diene\nintermediate generated during the catalytic process, offers alternative\nsolutions for organic synthesis.