Superelectrophilic-Initiated C-H Functionalization at the β-Position of Thiophenes: A One-Pot Synthesis of -Stereospecific Saddle-Shaped Cyclic Compounds.

Superelectrophilic-initiated direct C-H functionalization of thiophenes at the β-position was developed. A series of -stereospecific -thiophene-fused cyclic compounds () with saddle-shaped structure were prepared in 17-30% yields through a one-pot superelectrophilic Friedel-Crafts reaction of dihydroindenofluorene with thiophene derivatives. From the crystal packing analyses of , its skeleton shows both strong intermolecular π-π stacking and C-H···π stacking. Furthermore, the ring-dependent photophysical properties of were confirmed by UV-vis absorption and photoluminescence spectroscopy as well as through the study of their fluorescence quantum yield.