ABSTRACT Substitution of polycyclic aromatic hydrocarbons utilizing chromium tricarbonyl complexes has been extended to include pyrene, fluoranthene and anthracene in addition to the known examples of phenanthrene and naphthalene. Significant increases in the yields of the pyrene and anthracene complexes have been accomplished by treating the arene with tricarbonyltriammoniachromium complex and boron trifluoride etherated as the complexing system. The success of benzylic deprotonation reactions of the complexes and oxidation to an alcohol or ketone was substrate and condition dependent. Arene ring deprotonation followed by reaction with an electrophile led to formation of hydroxylֽ silyl and carboethoxy substitution products in good yields. Preparation and some disubstitution reactions of bis (chromiumtricarbonyl) complexes of phenanthrene and pyrene were also examined. These procedures allow substitution of polycyclic aromatic hydrocarbons in two steps to derivatives with regiochemistry not readily available by standard electrophilic substitution techniques.
Buy this Article
|