ChemInform Abstract: p‐Toluenesulfonic Acid‐Promoted Selective Functionalization of Unsymmetrical Arylalkynes: A Regioselective Access to Various Arylketones and Heterocycles.

Abstract

Hydration reactions of internal arylalkynes are efficiently performed using catalytic or stoichiometric amounts of TosOH in EtOH under microwave irradiation to give aryl ketones. Compared to thermal heating, the substrate scope can be successfully extended to weakly reactive alkynes. Unsymmetrical diarylalkynes are regioselectively hydrated. Some alkynols are additionally etherificated on the hydroxy group by the alcohol solvent. Diarylalkynes, arylenynes as well as diaryldiynes bearing a methoxy or a methylthio substituent on the ortho-position undergo a regioselective 5-endo-dig-cyclization to afford 2-substituted benzofuran and benzothiophene derivatives, respectively. -(JACUBERT, M.; PROVOT*, O.; PEYRAT, J.-F.; HAMZE, A.; BRION, J.-D.; ALAMI*, M.; Tetrahedron 66 (2010) 21, 3775-3787,