sulfuric acid; toluene-4-sulfonic acid in methanol T=0 - 5°C; ceramic diaphragm, carbon-rod anode, platinum cathode, 4.5 F/mol, 0.1A, cathode potential -1.45 to 1.65V vs. SCE;

piperidine-4-carboxylic acid functionalized Fe3O4 nanoparticles in dichloromethane T=80 - 100°C; Knoevenagel reaction; Inert atmosphere;