Nickel‐Catalyzed <scp>LiCl</scp>‐Controlled Switchable Carboxylation of Aryl C—F Bonds with One or Two Molecules of <scp>CO₂</scp>

Comprehensive Summary The use of CO 2 as a renewable C1 source for the synthesis of value‐added chemicals can contribute to a more sustainable chemistry. In this work, a nickel‐catalyzed amide‐directed carboxylation of aryl C−F bonds with CO 2 has been developed. The reaction is switchable controlled by LiCl to react with one or two molecules of CO 2 to afford valuable phthalimides or α‐hydroxycarboxylic acid derivatives. Further study shows that the reaction is a step‐by‐step process. The first step is a nickel‐catalyzed carboxylation of aryl C−F bonds with CO 2 and tandem cyclization to afford phthalimides. The second step is a nickel‐catalyzed C−N bond carboxylation of phthalimides with CO 2 , and intramolecular nucleophilic addition of amide anion to the carbonyl. The carboxylation of phthalimides with CO 2 is also developed based on this reaction. The work features inert C−F bond functionalization, amide C−N bond activation, and multiple CO 2 incorporation. Mechanistic studies indicate that the azanickelacycle intermediates play an important role, and LiCl facilitates the reduction of Ni(II) to Ni(I) and promotes the carboxylation with the second molecule of CO 2 . This protocol provides an efficient route for C−F bond functionalization under mild conditions via the chemical fixation of one or two molecules of CO 2 .