Mechanistic insights into copper-catalyzed aerobic oxidative coupling of N–N bonds† † Electronic supplementary information (ESI) available: Synthesis and characterization data, kinetics time courses, and electrochemical and X-ray crystallographic data. CCDC 1949421. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c9sc04305e

ABSTRACT: Catalytic N–N coupling is a valuable transformation for chemical synthesis and energy conversion. Here, mechanistic studies are presented for two related copper-catalyzed oxidative aerobic N–N coupling reactions, one involving the synthesis of a pharmaceutically relevant triazole and the other relevant to the oxidative conversion of ammonia to hydrazine. Analysis of catalytic and stoichiometric N–N coupling reactions support an “oxidase”-type catalytic mechanism with two redox half-reactions: (1) aerobic oxidation of a CuI catalyst and (2) CuII-promoted N–N coupling. Both reactions feature turnover-limiting oxidation of CuI by O2, and this step is inhibited by the N–H substrate(s). The results highlight the unexpected facility of the N–N coupling step and establish a foundation for development of improved catalysts for these transformations. Mechanistic studies provide valuable insights into Cu-catalyzed N–N coupling reactions relevant to energy conversion and pharmaceutical synthesis.

SUBMITTER: Ryan M 

PROVIDER: S-EPMC8146583 | biostudies-literature |

REPOSITORIES: biostudies-literature