The complexation of a Cr(CO)3 unit to an aromatic hydrocarbon enhances the benzylic position towerds attack by base and the resulting carbanion reacts with carbonyl compounds to produce a complexed alcohol; this reaction may be used to functionalize the benzylic position of an aromatic hydrocarbon.
treated with potassium t-butoxide in dimethyl sulphoxide the chromium tricarbonyl complex of 3-(2-fluorophenyl)propan-1-ol underwent a rapid intramolecular nucleophilic substitution to give the corresponding complex of chroman, from which the heterocycle was obtained by oxidation with iodine. With metal alkoxides the chromium tricarbonyl complex of 2-(2-fluorophenyl)ethanol gave either mixtures (from which