Regioselective magnesiations of functionalized arenes and heteroarenes using TMP2Mg in hydrocarbons† Andreas Hess,‡a Nurtalya Alandini,‡a Hasret C. Guelen,a Jan P. Prohaskaa and Paul Knochel *a Abstract We report the preparation of a new hydrocarbon-soluble magnesium amide TMP2Mg (TMP = 2,2,6,6-tetramethylpiperidyl). This base showed excellent properties for the regioselective magnesiation of various arenes and heteroarenes bearing ethyl esters and carbamates under very mild reaction conditions.