Heteroleptic (NHC/MIC) Biscarbene Ag(I) and Au(I) Complexes: Synthesis, Characterization and Catalytic Applications

A series of hetero‐biscarbene silver(I) and gold(I) complexes of the general formula [NHC‐M‐MIC]PF6 (NHC = imidazol‐2‐ylidene, MIC = 1,2,3‐triazol‐5‐ylidene) have been prepared via the treatment of NHC‐M‐Cl precursors in reaction with an in situ generated mesoionic carbene (MIC). The new heteroleptic complexes have been fully characterized including NMR spectroscopy, elemental analysis, melting points and single crystal X‐ray diffraction. The silver(I) derivatives were employed successfully in the solvent free KA2 (ketone‐alkyne‐amine) coupling for the preparation of a series of quaternary carbon‐containing propargyl amines while, the gold(I) biscarbenes, demonstrated a good performance in the A3 (aldehyde, amine, alkyne) coupling and the benzylic oxidation processes under low catalyst loadings.