ZIF-67 Derived Co/NC Nanoparticles Enable Catalytic Leuckart-type Reductive Amination of Bio-based Carbonyls to N-Formyl Compounds

Graphical Access to bio-nitrogenous chemicals : A Co-embedded N-doped carbon nanocatalyst can efficiently promote Leuckart-type reductive amination of biomass-derived carbonyls to prepare N-formyl compounds, which benefits from the synergy of its Co NPs and N base sites. The initial formation of the C−N bond occurs between carbonyls and H 2 NCHO rather than HCOONH 4 . It is of great significance to develop non-precious metal catalysts with excellent catalytic activity, stability, and acid resistance for biomass valorization. Herein, catalytic amination of biomass carbonyl compounds was achieved via a Leuckart-type reaction over Co nanoparticles (NPs) embedded N -doped carbon catalyst, which was prepared by thermolysis of ZIF-67 precursor at different temperatures in the N 2 atmosphere. The Co/NC-800 catalyst exhibited excellent catalytic activity and recyclability in furfural reductive amination to mono-substituted formamide, which was attributed to the synergistic catalytic action of Co NPs and nitrogen base sites of the catalyst. The reductive amination mechanisms were elucidated by theoretical calculations, and showed that the initial formation of C−N bond was derived from the condensation of furfural and formamide, followed by dehydration to form C=N double bond, which was then reduced by hydrogen species Co−H − and NH + . The developed catalytic system was applicable to different carbonyls for the synthesis of corresponding N -formyl compounds with up to 99 % yield.