Tetrachlorinated Polycyclic Aromatic Dicarboximides: New Electron-Poor π-Scaffolds and NIR Emitters by Palladium-Catalyzed Annulation Reaction.
Magnus MahlKazutaka ShoyamaJessica RüheVincenzo GrandeFrank WürthnerPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2018)
Herein we report a palladium-catalyzed annulation reaction consisting of a Suzuki-Miyaura cross-coupling and a C-H arylation cascade for the synthesis of tetrachlorinated polycyclic aromatic dicarboximides (PADIs). This convergent synthetic route afforded a broad series of hitherto unknown electron-deficient PADIs under optimized reaction conditions by coupling of a dibromo-tetrachloro-perylene dicarboximide with different polycyclic aromatic hydrocarbon (PAH) boronic acid pinacol esters in up to 89 % yields. The new PADI compounds show broad absorption in the visible range and some of them emit in the near-infrared (NIR) region. Cyclic and square wave voltammetric studies revealed that these tetrachlorinated PADIs are more electron-deficient than a non-chlorinated reference compound and they possess lower lying frontier orbitals. Thus, the newly synthesized electron-poor PADIs are potential n-type semiconductors. Moreover, these chlorinated PADIs are interesting building blocks for the construction of large π-extended arrays by metal-mediated coupling reactions.
Keyphrases
- electron transfer
- solar cells
- polycyclic aromatic hydrocarbons
- amino acid
- photodynamic therapy
- electron microscopy
- fluorescence imaging
- room temperature
- fluorescent probe
- gas chromatography
- single cell
- high density
- drug delivery
- human health
- reduced graphene oxide
- tandem mass spectrometry
- mass spectrometry
- light emitting