Alkali‐Metal‐Alkoxide Powered Zincation of Fluoroarenes Employing Zinc Bis‐Amide Zn(TMP)2

Abstract

AbstractReminiscent of Lochmann‐Schlosser superbase recipes, the addition of two molar equivalents of KOtBu to Zn(TMP)2 (TMP=2,2,6,6‐tetramethylpiperidide) transforms this mild zinc bis‐amide base to a powerful metalating agent able to perform facile regioselective zincation of a wide range of sensitive fluoroarenes. Structural authentication of the intermediates post Zn−H exchange demonstrates activation of both TMP groups to form a range of higher order bis‐aryl potassium zincates, isolable as solids and further functionalized in electrophilic interception reactions. Studies assessing the role of KOtBu reveal that the first equivalent undergoes co‐complexation with Zn(TMP)2, enabling kinetic activation of the amide groups; whereas the second equivalent stabilizes the metalated intermediate preventing ligand redistribution. Showcasing its metalating power, this bimetallic KOtBu/Zn(TMP)2 partnership, can effect zincation of toluene and benzene at room temperature.