Electrochemical Trideuteromethylation with AcOD- d ₄ : A Route to CD ₃ -Labeled Building Blocks

Deuterium substitution (CH 3 → CD 3 ) can enhance metabolic stability via the kinetic isotope effect and enable bioanalytical mass shifts. We report an electrochemical Kolbe heterocoupling that installs CD 3 at aliphatic positions by coupling carboxylic acids with AcOD- d 4 . The reaction proceeds at room temperature under constant current with Pt electrodes and base. Diverse CD 3 -labeled building blocks are obtained in moderate to good yields, and the method avoids CD 3 I and deuterated solvents.