A stereo- and regio-controlled synthesis of bromothiophenyl C-nucleosides. Tandem bromination-ribosylation via halogen dance process

Metallation–ribosylation of 2-bromothiophene 1 when conducted at room temperature afforded the original glycosylated dibromothiophene 3b following a regiocontrolled halogen transfer-based halogen-dance process. Then, stereocontrolled reduction-cyclization of hemiacetals 3a–c allowed straightforward access to the halogenated thiophenyl-C-nucleosides 6a–c.