Synthesis of Fluorine-Containing Tetraarylanthracenes via Ruthenium-Catalyzed C-O or C-F Arylation and their Crystal Structures

Tetraarylanthracenes containing several fluoro groups were synthesized using the ruthenium-catalyzed C-O or C-F arylation with arylboronates and their structural and spectroscopic studies were conducted. The RuH ₂ (CO)(PPh ₃) ₃ -catalyzed C-O arylation of aromatic ketones was found to be effective for the introduction of aryl groups containing multiple fluoro groups. Anthracenes possessing fluorinated aryl groups were prepared in two steps from 1,4,5,8-tetramethoxyanthraquinone by C-O arylation and reduction of the carbonyl groups. A tetraphenylanthracene containing a fluorinated anthracene moiety was also prepared using C-F phenylation of octafluoroanthraquinone. Single-crystal X-ray diffraction analysis showed that the positions of fluoro groups on the tetraarylanthracenes lead to notable difference in the crystal packing structures. The larger difference between the tetraarylanthracenes was observed in the fluorescence spectra in the solid state than those in chloroform.