Reactions of Zirconocene Butadiyne or Monoyne Complexes with Nitriles: Straightfoward Synthesis of Functionalized Pyrimidines

Zirconium-mediated multicomponent reactions of silyl-butadiynes with two molecules of aryl nitriles are described, which provide rapid access to polysubstituted pyrimidines in a regioselective manner and in one pot. Employing aliphatic nitriles results in coupling of only one nitrile, leading to the formation of enynyl ketones after hydrolysis. A zirconocene monoyne complex undergoes similar reactions with nitriles to form highly substituted pyrimidines.