Carbon dioxide: A reagent for the protection of nucleophilic centers and the simultaneous activation of alternative locations to electrophilic attack: 15. A synthetic method for the α-substitution of N-phenylbenzylamine

N-Phenylbenzylamine has been converted into a variety of α-substituted derivatives in one-pot sequences, using carbon dioxide both for N-protection and α-carbon activation, and then subsequent lithiation at the α-carbon atom by either tert- or n-butyllithium. The resulting lithium carbamate reacts with electrophiles, followed smooth acid-catalyzed decarboxylation under mild condition to give α-substituted N-phenylbenzylamines in good yields.