A 6π Azaelectrocyclization Strategy towards the 1,5,9‐Triazacoronenes

Abstract

We present the instance of two aromatic double bonds and an imine double bond involved thermal 6π-azaelectrocyclization and, on this basis, a one-step synthesis of triazacoronenes (TACs) from triphenylene-1,5,9-triamines and aldehydes under nonacidic conditions. This method has several advantages such as simplicity, high yields, and extensive substrate scope. A plausible reaction mechanism has been proposed with several experimental supports. A typical derivative shows a unique dimer holding together via a π-π interaction and six H-bonds and a zigzag superstructure stabilized by three centered H-bonds and Br ··· π interaction between the adjacent dimers. Figure 1. Coronene and its triaza derivatives.

Palladium-Catalyzed Oxidative Annulation of Sulfoximines and Arynes by C–H Functionalization as an Approach to Dibenzothiazines

“…However, arynes have not been well-explored in the area of C–H activation because of their high reactivity, making this strategy very interesting but also very challenging . Stimulated by our recent findings on the palladium-catalyzed C–H functionalization/annulation reaction of N -alkoxybenzsulfonamides with arynes to produce tricyclic dibenzosultams and our continued interest in the synthesis of polycyclic aromatic hydrocarbons (PAHs), we envisaged that tricyclic dibenzothiazines could be prepared from sulfoximines and aryne precursors through a C–H/N–H functionalization and cyclization strategy (Scheme d).…”

Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

“… 11 Under optimized conditions ( Scheme 10 ), a wide variety of TAC derivatives ( 10.2 ) could be synthesized, with yields reaching 94%. 11 Acid-catalyzed conditions were used by Coskun et al to synthesize conjugated microporous polymers (CMPs) 10.6 from 1,5,9-triaminetriphenylene 10.1 and terephthalaldehyde. 12 The optical band gap and surface area of the resulting CMPs were found to correlate with the strength of the acid catalyst.…”

Synthesis, crystal structure, and properties of methyl-substituted coronene amide analogue

“…[5][6][7][8] Doping of heteroatoms in aromatic rings is an effective approach for modulating physico-electrochemical properties, and several synthetic studies of heterocoronenes have been reported. [9][10][11][12][13][14][15][16][17][18][19][20] As a coronene analogue containing amide linkages, the synthesis 17 and application to organic semiconductors 18 of a D 2h symmetric compound 1 have been reported. Recently, our group has synthesized 2, a new C 3 symmetrical coronene analogue with three peripheral amide linkages, by the cyclic trimerization of 2-bromo-4-(isobutylamino)benzoic acid, followed by palladium-mediated intramolecular biarylation.…”