Growing interests in nitrogen-containing molecules involving bioactive and functional materials have stimulated the recent development of synthetic methodologies where nucleophilic addition reactions to imino carbons are utilized in crucial steps. This article summarizes double nucleophilic addition reactions with α,β-unsaturated aldimines, addition reactions using alkynyl imines, “umpoled” reactions of α-imino esters, and the use of iminium salts as reactive electrophiles.