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 a-carbon activation,and then subsequent lithiation at the a-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.