An interesting aldehyde- and ketone-induced intermolecular tandem decarboxylation-coupling (Csp(3)-Csp) catalyzed by copper with use of natural alpha-amino acids as starting materials is developed under neutral conditions with the production of CO(2) and H(2)O as the only byproducts. Various functionalized nitrogen-containing compounds were obtained by this method. In these processes, interesting regioselectivites of the alkylation were observed, which has been rationalized by the relative stability of proposed resonance structures based on computation methods.