Modified Vilsmeier reactions of activated benzofurans with indolines: Synthesis of benzofuran-fused benzocarbazoles

Article abstract of DOI:10.1016/S0040-4039(99)00699-1

Regioselective reactions of 3-substituted 4,6-dimethoxybenzofurans with indolin-2-ones and triflic anhydride afforded 7- and/or 2-substituted indolo-benzofurans and the latter were cyclised to previously unknown benzofuran-fused benzocarbazoles using pall