Synthesis of 4,7′-Bibenzo[ b ]thiophenes Bearing Several Different Substituents at 2-, 2′-, 4′-, and 7-Positions; Structurally Featured Molecular Scaffolds for Selective Substitution

Four isomers of 4,7'-bibenzothiophene scaffolds bearing two different halogen (Br, Cl) and triisopropylsilyl substituents have been synthesized from the two multihalobenzo[b]thiophenes via iodoselective Miyaura borylation reaction using potassium benzoate as a base. Further investigation into the reactivity of 4,7'-bibenzothiophenes in substitution reaction, Suzuki Miyaura cross-coupling reaction, and C-H direct arylation reaction revealed that tetrasubstituted 4,7'-bibenzothiophenes can be synthesized site- (chemo-) selectively, which are promising novel components for molecular architecture.