Electrogenerated base (EG base) formed in a DMF–H2O (1.85 M)–Et4NOTs (0.1–0.2 M)–(Pt) system is effective for condensation of phenylacetonitrile and its related compounds with aldehydes, giving the corresponding cyanoalkylation compounds in good yields, and the concomitant dehydration of the adducts is minimized.