A novel copper-catalyzed aminomethylative etherification of N-allenamides/alkoxyallenes with N,O-acetals has been realized under mild reaction conditions, in which every single atom of N,O-acetals is incorporated into the newly formed molecules. Furthermore, in the presence of a chiral phosphoric acid, the asymmetric aminomethylative etherification of N-allenamides has been accomplished using N,O-acetals as bifunctionalization reagents.