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The selective construction of a diverse array of five-membered aromatic heterocycles from common starting materials is an attractive and challenging task. We report here that 5-alkylthio-pyrroles, 4-alkylthiocarbonyl-pyrroles and 2-alkylthio-4-tosyl-furans can be prepared, selectively, in a single operation using the readily available α-formyl ketene dithioacetals as common precursors, through their regiodivergent heterocyclization with α-acidic isocyanides controlled by the choice of suitable catalysts/promoters. [ABSTRACT FROM AUTHOR]

The reaction of dithioacetals (I) with nitriles (II) followed by a zinc-mediated one-pot reaction of the isolable intermediate (V) leads to 5-ethylthiopyrroles (III), whilst the copper-mediated reaction of the intermediate (V) affords 4-ethylthiocarbonylpyrroles (IV) via a second isolable intermediate (VI). [ABSTRACT FROM AUTHOR]