Facile dearomatizing radical arylation of furan and thiophene.

In the presence of catalytic diphenyl diselenide, reduced in situ to benzeneselenol, tributyltin hydride and V-70 promote the addition of aryl iodides to furan and thiophene. The adduct radicals are trapped by the selenol to give the 2-aryl-2,3-dihydro and 2-aryl-2,5-dihydro heterocyclic products. When the iodide is an o-iodophenol, a cyclization follows the radical addition and provides bridged bicyclic acetals. [reaction: see text]