Reinvestigation of the photoreaction of 1,4-bis(2,4,6-triphenylpyridinio)benzene: Synthesis of a diazonia derivative of hexabenzoperylene by multiple photocyclization

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

“…Embedding of two pyridinium rings in the hexabenzoperylene framework of 39.3 was achieved by Sato and co-workers in a simple two-step procedure ( Scheme 39 ). 68 First, condensation of a triphenylpyrylium salt 39.1 with p -phenylenediamine gave the dipyridinium product 39.2 , which was photocyclized by UV irradiation in MeOH/DCM solution in the presence of air, providing 39.3 in 15% yield. This compound had a twisted double helicene structure and was determined to exist as a mixture of enantiomers ( meso form was not found).…”

“… a Reagents and conditions: (a) p -phenylenediamine, DMF, 150 °C, 20 h, 39%; (b) 2:5 MeOH/DCM, air, hν (450 W high-pressure mercury vapor lamp), 14 h, 15%. …”

Multiple Heterohelicenes: Synthesis, Properties and Applications**

“…In 2016, the first synthesis of diazonia derivative of hexabenzoperylene (HBP) 44 by photo-induced oxidative cyclization was reported by Sato and coworkers. [60] Specifically, compound 44 was prepared in two step, by refluxing 2,4,6- triphenylpyrylium salt 41 with a primary amine 42 in DMF and subsequent photo-induced oxidative cyclization of intermediate 43 in the presence of O 2 (Figure 10). Compound 44 adopted twisted conformation, which was confirmed by 1 H NMR titration investigation with a chiral complexing reagent and TD-DFT calculations of absorption spectra.…”

Recent Advances in Multiple Heterohelicenes

“…[59] In 2016, the first synthesis of diazonia derivative of hexabenzoperylene (HBP) 44 by photoinduced oxidative cyclization was reported by Sato and coworkers. [60] Specifically, compound 44 was prepared in two step, by refluxing 2,4,6-triphenylpyrylium salt 41 with a primary amine 42 in DMF and subsequent photo-induced oxidative cyclization of intermediate 43 in the presence of O2.…”