Scheme 3. Boronic acid 25 as a versatile reagent for the incorporation of a fused benzothiophene ring to various π-systems^a. ^aConditions for the Suzuki–Miyaura reaction: see ESI.† Conditions for the cyclization: see footnote b in Fig. 1. Isolated yields for the cyclization step are shown. ^bSee footnote a in Fig. 1 for the conditions used for the cyclization. ^cNMR yield.