Efficient copper-catalyzed 1,2-difunctionalization of alkenes with commercially available BrCH2Cl as a chloromethylating source was carried out, in which mild conditions, high reactivity, excellent functional-group tolerance, and late-stage modification of a bioactive molecule are demonstrated. This strategy offers a solution for the diverse syntheses of nitrogen-containing terminal alkyl chlorides, a common synthetic handle that is promising for multiple derivatizations. Mechanistic studies indicate that a chloromethyl radical is involved in the catalytic cycle.