Lewis-Acid-Mediated Intramolecular Trifluoromethylthiolation of Alkenes with Phenols: Access to SCF3-Containing Chromane and Dihydrobenzofuran Compounds.

A Lewis-acid-mediated intramolecular trifluoromethylthiolation of alkenes with phenols that can offer direct access to SCF3-containing chromane and dihydrobenzofuran compounds was disclosed for the first time. Numerous SCF3-containing chromanes were obtained in moderate to good yields using γ-substituted 2-allyphenols as substrates. Meanwhile, various SCF3-containing dihydrobenzofurans with oxa-quaternary centers were also delivered in moderate to good yields using β-substituted 2-allyphenols as substrates.