Mechanistic insights into copper-catalyzed aerobic oxidative coupling of N-N bonds.
Chem Sci
; 11(4): 1170-1175, 2019 Dec 10.
Article
em En
| MEDLINE
| ID: mdl-34084374
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.
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MEDLINE
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En
Ano de publicação:
2019
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Article