CpCo-Benzoquinone Complexes: Convenient CpCo(I) PrecatalystsSynthesis and Reactivity.

We report an improved, convenient, and general synthesis of the air-stable complex CpCo-(DQ) (DQ = duroquinone), originally described by Schrauzer and Thyret in 1963, and applied this general protocol to the preparation of a series of related CpCo-(p-benzoquinone) complexes with yields ranging from 35 to 96%. The complexes were characterized by single-crystal X-ray diffraction, and the bonding characteristics were compared to those of other CpCo-olefin complexes. Their catalytic performance was evaluated in cyclotrimerization reactions under both thermal and photochemical conditions for the synthesis of pyridine and benzene derivatives.