Thiophene is a five-membered heterocyclic compound containing a sulfur heteroatom with the molecular formula C4H4S. Thiophene is aromatic and is very similar to benzene; electrophilic substitution reaction is easier than benzene, and it is mainly substituted at the 2-position. Thiophene ring system has certain stability to oxidant.
Dibenzofuran is an organic compound (C12H8O) consisting of two benzene rings fused to a central furan ring. Dibenzofuran can be synthesized by annealing and oxidative coupling methods of diphenyl ether, biphenyl derivatives, benzofuran, quinone. Most of the dibenzofuran-related natural products are metabolites of lichens or higher fungi. Lichen dibenzofurans appear to be formed by carbon-carbon oxidative coupling of orsellinic acid and its homologs.