Synthesis of [1]Benzothieno[2,3-b]quinolines via Transition-Metal-Free [3+3] Annulation of Nitroarenes and Benzo[b]thiophen-3-ylacetonitrile or 3-(Phenylsulfonylmethyl)benzo[b]thiophene Carbanions

Abstract

Benzo[b]thiophen-3-ylacetonitriles or 3-(phenylsulfonylmethyl)benzo[b]thiophenes react with nitrobenzene derivatives in the presence of potassium tert-butoxide and chlorotrimethylsilane to form, in good yields, 11-cyano- or 11-(phenylsulfonyl)[1]benzothieno[2,3-b]quinolines, respectively.