Efficient synthesis of 3,6,13,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes by selective C–H/C–O arylations of anthraquinone derivatives

Abstract

An efficient synthesis of tetrabenzo[a,d,j,m]coronene derivatives having alkyl and alkoxy substituents at the 3, 6, 13, and 16-positions was achieved based on the ruthenium-catalyzed coupling reactions of anthraquinone derivatives with arylboronates via C–H and C–O bond cleavage. The reaction sequence involving the arylation, carbonyl methylenation, and oxidative cyclization effectively provided various tetrabenzo[a,d,j,m]coronenes in short steps from readily available starting materials. Tetrabenzo[a,d,j,m]coronenes possessing two different types of substituents were obtained selectively by sequential chemoselective C–O arylation and C–H arylation. The 1H NMR spectra of the tetrabenzo[a,d,j,m]coronene product indicated its self-assembling behavior in CDCl3.

Ruthenium‐Catalyzedortho‐CH Bond Arylation Reactions

“…The general methodology for the access to hexaarylanthracenes was based on tetraarylation with an arylboronate followed by arylation of the ketonic groups with an aryl lithium reagent and then reduction of the corresponding alcohol. On the other hand, the synthesis of coronenes involved first ortho-directed C-H bond arylation followed by dimethylenation and finally oxidative cylization promoted by FeCl3 (Scheme 6) [59,60]. Under similar conditions, the use of symmetrical diboronates made possible the ring extension in a linear manner starting from acetophenone substrates to give para-diarylbenzene products (Scheme 7) [61].…”

One-Pot Synthesis of Multiarylated Benzophenones via [3 + 2 + 1] Benzannulation of Ketones, Alkynes, and α,β-Unsaturated Carbonyls

“…Therefore, a regioselective synthetic method for arylated benzophenones is an important unsolved problem. Ruthenium-catalyzed arylation of benzophenones to ortho arylated benzophenones has been recently reported . In 2022, our group reported that 3-phenylpropyl ketones are dehydrogenatively transformed into meta -aryl benzophenones (Scheme a) .…”