Herein, a novel Cu-catalyzed four-component cascade reaction, which encompasses styrenes, diazo compounds, amines, and tert-butyl hydroperoxide (TBHP), was developed for the synthesis of β-ester-γ-amino ketones. Mechanistically, this transformation was initiated by the interception of an electrophilic Cu-based carbene with nucleophilic α-aminoalkyl radicals, followed by a radical cascade process and an ionic Kornblum–DeLaMare reaction. The methodology was also distinguished by its wide substrate scope, easily available starting materials, and operational simplicity.