Dehydrogenation of heterohelicenes by a Scholl type reaction. Dehydrohelicenes

Electronic structure, aromaticity and spectra of hetero[8]circulenes

“…In particular, the UV-Vis absorption spectra of thia [7]circulenes 13 and 32 ± 34 in chloroform 33 display a pronounced vibrational structure similar to that observed for dehydrohelicenes. 122 The first long-wavelength absorption maximum of circulenes 13 and 32 ± 34 undergoes a red shift, on the average, by 20 nm with respect to the corresponding band of dehydrohelicenes. In addition, the absorption spectra of thia [7]circulenes are poorly sensitive to the number of thiophene rings in the macrocycle.…”

“…Dehydrohelicenes should be considered as the first synthesized heterocyclic quasicirculenes. 34,49,121,122 The synthesis of these compounds is based on the intramolecular cyclization of the corresponding heterohelicenes, 120 and they are the starting compounds in the synthesis of thia [7]circulenes. More recently, dehydrohelicenes 39 and 40 containing the inner eight-membered core 35,123 Figure 10.…”

Heliphenes and Related Structures

“…In a theoretical exploration of hypothetical intramolecular and intermolecular dehydrogenations of helicenes, interesting structures were published [84]. Wynberg and coworkers [85] had described dehydrohelicenes obtained from [5]and [6]helicenes by AlCl 3 -catalyzed intramolecular dehydrogenation (Scholl reaction [86]).…”

Synthesis and Structures of Multifunctionalized Helicenes and Dehydrohelicenes: An Efficient Route to Construct Cyan Fluorescent Molecules

“…Dehydrohelicenes [15] are compounds in which the two heliA C H T U N G T R E N N U N G cal termini of a helicene are connected by a s bond. As a special class of polycyclic aromatic hydrocarbon (PAH), they could have the wide potential applications in materials science.…”