ETUDE DES REACTIONS DE SRN1-PARTIE 10 ACTION DE SULFANIONS SUR LES HALOGENURES D'ARYLE FONCTIONNALISES. SYNTHESE DIRECTE DE BENZOTHIOPHENES ET THIENOPYRIDINES

Article abstract of DOI:10.1016/S0040-4020(01)88635-X

Functionalized aromatic halides Ar₁XY (Ar₁=C6H4, Y=OCH3,CONH2,CN,COCH3,CHO,COC6H5) undergo S_RN1 reactions with sulphur anions ^-SR, either simple (R=C2H5,CH2C6H5) or functionalized (R=(CH2)2OH,(CH2)2CO2Et,CH2CO2Et).Products Ar₁YS^- formed from the fragmentation of the radical anion Ar₁YSR^- are related to the redox potential of the aryl moiety Ar₁Y and with the energy of the bond S-R.In the heterocyclic series (Ar₂=pyridine, Ar₃=quinoline) a similar relationship appears but a competitive S_N(AR) reaction occurs for pyridine substrates bearing an electron withdrawing group.A direct synthesis of benzothiophen via S_RN1 reaction and an improved synthesis of thienopyridines based on the S_N(Ar) reaction are reported.