Lithiation of 2,5-dimethylazaferrocene

Reaction of 2,5-dimethylazaferrocene with sec-BuLi/TMEDA in THF at −78 °C, followed by quenching with D₂O brought about incorporation of deuterium into the Cp ring (54%), methyl groups (38%) and the pyrrolyl β-position (8%). When benzyl chloride or p-methoxybenzaldehyde was used as quenchers products originated from the lateral lithiation were only formed, accompanied by recovered starting material. For this reaction a radical pathway is suggested.