Thermal decomposition reactions of n‐alkylated 2‐aminobiphenyls to carbazole and phenanthridine

Abstract

+ + + 1a-c 3 4 5 6 2 5 R 2 CaO CaOThermal cyclization reactions were examined by passing vapors of N-alkylated 2-aminobiphenyls 1a-c and 2 over calcium oxide at 450-600°C under nitrogen carrier gas. The reactions yielded 9methylcarbazole 3, carbazole 4, phenanthridine 5 and phenanthrene 6. The major product for the reactions of 1a, 1b and 2 was phenanthridine 5 while that of 1c was carbazole 4.

Heterostructures through Divergent Edge Reconstruction in Nitrogen‐Doped Segmented Graphene Nanoribbons

“…Rather than relying on the co‐polymerization of two dissimilar molecular precursors, we designed a molecular building block bearing a 9‐methyl‐9 H ‐carbazole substituent as an internal reactive moiety ( 1 in Figure ). Previous work demonstrated that the thermally induced rearrangement of 9‐methyl‐9 H ‐carbazole at T >500 °C on a CaO support leads to a product mixture containing both phenanthridine and carbazole . Once incorporated into the edges of a fully fused GNR, the electron‐rich 9‐methyl‐9 H ‐carbazole could thus be converted into an electron‐deficient phenanthridine substituent through a thermally induced ring‐expansion/dehydrogenation reaction.…”

“…Here, the bottom-up synthesis of chevron GNRs decorated with reactivef unctional groups derived from 9-methyl-9H-carbazole is reported. [7] Once incorporated into the edges of af ully fused GNR, the electron-rich 9-methyl-9H-carbazole could thus be converted into an electron-deficient phenanthridine substituent through at hermally induced ring-expansion/dehydrogenation reaction. The selective chemical edge-reconstruction of carbazole-substitutedc hevron GNRsr epresents ap ractical strategyf or the controlled fabrication of spatially defined GNR heterostructures from asingle molecular precursor.…”

“…Previous work demonstrated that the thermally inducedr earrangemento f9methyl-9H-carbazole at T > 500 8Co naC aO support leads to ap roduct mixture containingb oth phenanthridine and carbazole. [7] Once incorporated into the edges of af ully fused GNR, the electron-rich 9-methyl-9H-carbazole could thus be converted into an electron-deficient phenanthridine substituent through at hermally induced ring-expansion/dehydrogenation reaction. This transformation is of particular interest in the context of rationalG NR heterostructure engineering, because it woulda llow for av ersatile and reliable strategy towardt he incorporation of heterocyclesw ith diametrically opposite inductive effects (the electron-accepting phenanthridine and electron-donating carbazole) at defined positions along the GNR backbone.…”

Synthesis of Fused pyrazolo[4,3‐c]quinolines through KI‐Promoted Cyclization of Pyrazole‐arylamines and Benzyl Bromide

“…To gain insight into the reaction mechanism, we prepared potential intermediate N-benzyl-2- (1,3-diphenyl-1H-pyrazol-5yl)aniline from 2-(1,3-diphenyl-1H-pyrazol-5-yl)aniline and benzaldehyde 4 a [14] and treated it under the optimal condition Scheme 3. To study the mechanism by using probable intermediate Scheme 4.…”

Recent Advances of Hierarchical and Sequential Growth of Macromolecular Organic Structures on Surface

“…By a thermally activated ring expansion/dehydrogenation reaction, the electron-rich carbazole could be converted into the electron-deficient phenanthridine [120]. In this work, authors succeeded to partially convert the carbazole groups into phenanthridine, opening the way towards the fine tuning of the materials bandgaps by the presence of electron-rich and electron-poor groups onto the same structures (see Figure 20B).…”