Discovery of a New Template for Anticancer Agents: 2′-deoxy-2′-fluoro-4′-selenoarabinofuranosyl-cytosine (2′-F-4′-Seleno-ara-C)

The first synthesis of 2'-deoxy-2'-fluoro-4'-selenoarabinofuranosyl pyrimidines as potent anticancer agents was accomplished using the DAST fluorination as a key step. It was first revealed that selenium atom participated in the DAST fluorination of 4'-selenonucleosides and that conformational bias induced by bulky selenium acted as a decisive factor in the DAST fluorination. Among compounds tested, 2'-F-4'-seleno-ara-C (4a) exhibited highly potent anticancer activity in all cancer cell lines tested and was more potent than ara-C (1).