Mild Approach to Nucleoside Analogues via Photoredox/Cu-Catalyzed Decarboxylative C–N Bond Formation. Total Synthesis of Oxetanocin A

The conventional N-glycosylation methods for nucleoside synthesis usually require strongly acidic or basic conditions. Here we report the decarboxylative C­(sp3)–N coupling of glycosyl N-hydroxyphthalimide esters with nucleobases via dual photoredox/Cu catalysis, which offered a mild approach to nucleoside analogues. A total synthesis of oxetanocin A, an antiviral natural product containing an oxetanose moiety, has been achieved by using this method.