Nickel foam (0.16x1x2 cm) was activated via sonication under a solution of sulfuric acid 3 M for 10 min. The catalyst was then washed with water and used without any further manipulation. The H-cell configuration consists of a nickel foam as working electrode, Ag/AgCl/AgCl 3M as reference electrode, and a Pt wire as counter electrode. The substrate was placed at the working compartment, and both chambers were filled with ethanol (6.25 mL) and aqueous sulfuric acid (0.25 M, 18.75 mL). A chronoamperometry experiment was conducted (-0.9 V, 18 h). Nickel foam was removed from the set-up and washed with 2 mL EtOH under sonication for 5 min. The solution from the working electrode was collected and rinsed with 10 mL EtOAc. Both fractions were combined, phases separated, and the aqueous phase extracted twice with 10 mL EtOAc. For the substrates with low boiling point, or that led to emulsions during extraction, CH2Cl2 was used instead of EtOAc for the extractions. The combined organic phases were dried over MgSO4, filtered and solvent evaporated via rotary evaporator or distillation. The compounds were purified via column chromatography.