Synthesis of Annulated Anthracenes, Carbazoles, and Thiophenes Involving Bradsher-Type Cyclodehydration or Cyclization-Reductive-Dehydration Reactions

Article abstract of DOI:10.1002/ejoc.201500493

A conventional BF₃·OEt₂-mediated Bradsher-type cyclodehydration of 2-arylmethyl benzaldehydes in CH₂Cl₂ at room temperature gave polycyclic aromatic and heteroaromatic compounds. Alternatively, these compounds could be synthesized in better yields from 2-arylmethylbenzoic acids by triflic-acid-mediated cyclization followed by reductive dehydration.