Acid-Catalysed or Radical-Promoted Allylic Substitution of 2-Methylene-2,3-dihydrobenzofuran-3-ols with Thiol Derivatives: a Novel and Expedient Synthesis of 2-(Thiomethyl)benzofurans

作者：Gabriele Bartolo^*; Mancuso Raffaella; Salerno Giuseppe

来源：European Journal of Organic Chemistry, 2010, 2010(18): 3459-3464.

DOI：10.1002/ejoc.201000289

• Allylic substitution
• Benzofurans
• Thioethers
• Oxygen heterocycles
• Nucleophilic substitution
• Radical reactions

The 2-thiomethylbenzofuran derivatives 3 are conveniently prepared in good yields through the reactions between the readily available 2-methylene-2,3-dihydrobenzofuran-3-ols 1 and the thiol derivatives 2 (including alkyl thiols, thiophenol, and thioacetic acid). The allylic substitution process may be either acid-catalysed or promoted by radical initiators. In the first case, the reactions are carried out at 90 degrees C in 1,2-dimethoxyethane (DME) as the solvent in the presence of H(2)SO(4) as the proton source. The radical-promoted reactions take place in DME at 90 degrees C in the presence of azobis(isobutyronitrile) (AIBN) or benzoyl peroxide (BP) as the radical initiator.

• 出版日期2010-6