Regioselective magnesiations of functionalized arenes and heteroarenes using TMPMg in hydrocarbons.

We report the preparation of a new hydrocarbon-soluble magnesium amide TMPMg (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. Subsequent trapping with aryl iodides (Negishi cross-coupling) gave access to a range of highly functionalized valuable building blocks.