Alkali‐Metal‐Alkoxide Powered Zincation of Fluoroarenes Employing Zinc Bis‐Amide Zn(TMP)<sub>2</sub>
Neil R. Judge, Eva Hevia
Abstract
Abstract Reminiscent of Lochmann‐Schlosser superbase recipes, the addition of two molar equivalents of KO t Bu 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 KO t Bu 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 KO t Bu/Zn(TMP) 2 partnership, can effect zincation of toluene and benzene at room temperature.