摘要：SummaryNitrile (C≡N bond) activation for direct organic synthesis has been less explored so far due to a high redox potential of nitrile and its low dissociation energy of C−CN bond. Herein, we demonstrate a direct reductive coupling of nitriles and 1,2-phenylenediamines to yield various benzimidazoles in excellent yields (95%–99%) by using rhodium phosphide (Rh2P) catalyst supported on lignin-derived carbon (LC) using H2(or hydrazine hydrate) as a hydrogen source. The high catalytic performance of Rh2P/LC is attributed to enhanced charge transfer to Rh and strong P−Rh interactions. Our isotope trace experiment confirms the presence of H/D exchange between H2and the inert –CD3group of CD3CNviaan intramolecular D-shift. Reusability of Rh2P/LC is further demonstrated by a seven-time recycling without evident loss of activity. This research thus highlights a great potential in organic transformation with nitrile as a synthetic building block.Graphical abstractDisplay OmittedHighlights•Nitrile was developed as synthetic building block for organic synthesis•Reductive coupling of nitriles to 1,2-phenylenediamines yielded benzimidazoles•Strong P−Rh interaction and charge transfer to Rh enhanced Rh2P activity•H/D exchange between H2and –CD3in CD3CN occurred via intramolecular D-shiftChemistry; Inorganic chemistry; Catalysis; Organic chemistry; Organic synthesis
