The synthesis and reaction of N-phenyl alkynyl imine-hexacarbonyldicobalt complexes

N-Phenyl dialkynyl imines react with octacarbonyldicobalt to give N-phenyl dialkynyl imine-mono(hexacarbonyldicobalt) complexes. The structure of one of them, [PhNC(CCPh)₂]Co₂(CO)₆ (4b), has been determined by X-ray crystallography, which shows that the phenyl ring on the imino nitrogen is oriented over the free acetylenic bond. The N-phenyl dialkynyl imine-mono(hexacarbonyldicobalt) complex thus formed undergoes cotrimerization with disubstituted alkynes to give pentasubstituted aryl alkynyl N-phenyl imines. N-Phenyl alkenyl alkynyl imines, prepared by 1,2-reduction of N-phenyl dialkynyl imines followed by isomerization, were also transformed into pentasubstituted aryl alkenyl N-phenyl imines via the corresponding N-phenyl alkynyl imine-hexacarbonyldicobalt complexes.