The photocyclisation of anilino-pyridines to carbolines

γ-Carbolines and their hydrogenated derivatives. 1. Aromatic γ-carbolines: methods of synthesis, chemical and biological properties (review)

“…During irradiation in cyclohexane or THF 4-(phenylamino)pyridine undergoes oxidative photocyclization [19] accompanied by the formation of γ-carboline. This was first noticed in diphenylamines, which are converted under these conditions into the corresponding carbazoles [20].…”

Palladium complexes of N-aryl-2-pyridylamines

“…(ii) The dipyridylamine intermediate 7 was prepared by a 1,3-cycloaddition reaction of nitropyridyl isocyanate 6 and pyridine N-oxide followed by a [1,5] sigmatropic shift and decarboxylation, as previously reported by us (Scheme 2b) [23]. (iii) Both dipyridylamine intermediates (7,11) were prepared by Buchwald amination from 2-bromo-5-nitropyridine (8) and 2-aminopyridine and its 5-methyl derivative (10) in 62-64% yield (Scheme 2c and d). The nitropyridylcompound 7 has previously been prepared by nitration of dipyridylamine [24][25][26], while compound 11 is hereby prepared for the first time.…”

“…Our results for the preparation of the appropriate N-aryl-2-pyridylamine substrates (4,7,11) and the subsequent palladium promoted reactions are discussed below.…”

“…Such Pd(OAc) 2 activation reactions of substrates 1b,c would thus afford N-aryl-2-pyridylamine-palladium complexes. Consequently, the formation of the tricyclic products 2b,c (Scheme 1) and the new a-carboline (5) [7][8][9][10][11][12] and pyridoazaindol (9,12) products from the N-aryl-2-pyridylamino substrates 4, 7, 11 (Scheme 2a-d) were not expected.…”

Light and Oxygen Protective Properties of Materials Induced by Surfactant Molecular Complex Formation

“…2 the time dependence on absorption shifts very smoothly, merely involving a decrease in the main peak height at 286 nm (ε = 1.9 × 10 4 ), without showing any other spectral changes in the wide wavelength region examined. As for this complex additive and its related amines, it is reported that in organic media UV light induces them to undergo oxidative cyclization into carbazole and companion compounds (21)(22)(23)(24). As far as our study is concerned, however, we can disregard whether the photo process of such inversion might be induced also in the SMC crystal matrices, since no carbazole-related peaks, e.g., at 233 nm (ε = 4.6 × 10 4 ), 256 nm (ε = 2.0 × 10 4 ), 322 nm (ε = 3.6 × 10…”