Metal Arene Complexes in Organic Synthesis. Hydroxylation, Trimethylsilylation, and Carbethoxylation of Some Polycyclic Aromatic Hydrocarbons Utilizing η6-Arene-Chromium Tricarbonyl Complexes

Article abstract of DOI:10.1021/jo00050a023

The deprotonation of polycyclic aromatic hydrocarbon (PAH) chromium tricarbonyl complexes (PAH = naphthalene, anthracene, phenanthrene, pyrene, fluoranthene) using an in situ technique where the PAH complex, the base (LiTMP or LDA), and the electrophile (trialkyl borate, trimethylsilyl chloride, or ethyl chloroformate) were placed in solution simultaneously resulted in hydroxylation, trimethylsilylation, or carbethoxylation of the PAH after oxidative workup where the regiochemistry was controlled by steric factors.As a result, substitution at positions of the PAHs not readily available by electrophilic substitution were obtained in some cases.Conditions minimizing isomer mixtures and factors affecting the regiochemistry and the scope of the reaction sequence were examined.