One-Pot Synthesis of Azanucleosides from Proline Derivatives - Stereoselectivity in Sequential Processes

Common amino acid derivatives can be transformed in one-step fashion into N-azanucleosides. The method is a sequential process initiated by a domino radical decarboxylation/oxidation reaction; an acyliminium ion is formed as an intermediate and can be trapped by nitrogen bases (purines, pyrimidines, and benzotriazole). The mildness of the reaction conditions and the good yields obtained make this procedure an interesting alternative to the conventional processes. Good stereoselectivities were obtained with 4-(silyloxy)proline derivatives as substrates.