Regiochemical observations depending on electrophiles in directed lithiation of 1,3-diheteroatom substituted arene tricarbonylchromium complexes

Directed lithiation of 1,3-diheteroatom substituted arene chromium complexes gave regioisomeric compounds depending on the nature of quenching electrophiles. Quenching of lithiated intermediate generated from 3-methoxybenzaldehyde ethyleneacetal chromium complex with aldehyde, 1,2-dibromotetrafluoroethane, ethyl formate, etc. gave regioselectively 2-functionalized chromium complexes, while trap with DMF afforded 4-formylated chromium complex.