Electric fields as “smart reagents”

The image shows a schematic representation of oriented external electric-field (OEEF) in an electrostatic catalysis (top panel), and copper (Cu+)-catalyzed click cycloaddition (bottom panel) in a confined microfluidic channel between two gold electrodes. The azide moiety (1) is immobilized on the gold surface via thiol-gold chemistry, and the ferrocene alkyne derivative (2) is flowed continuously to avoid its depletion on the functionalized gold surface. b, c Schematic drawing showing parts of the microfluidic cell prior to its assembly (in panel b) and the assembled microfluidic cell with a section-cut in the top part to demonstrate the confined reaction area formed between two gold electrodes using a spacer (in panel c).