245-72-7Relevant academic research and scientific papers
Examination of the mechanism of the intramolecular amination of N-(3-bromopyridin-2-yl)azaheteroarylamines and N-(2-chloropyridin-3-yl)azaheteroarylamines: a Pd-catalyzed amination and/or a base-assisted nucleophilic aromatic substitution?
Loones, Kristof T.J.,Maes, Bert U.W.,Herrebout, Wouter A.,Dommisse, Roger A.,Lemière, Guy L.F.,Van der Veken, Benjamin J.
, p. 3818 - 3825 (2007)
The intramolecular amination of N-(3-bromopyridin-2-yl)azaheteroarylamines and N-(2-chloropyridin-3-yl)azaheteroarylamines was investigated. In this way we unraveled the mechanism of the ring closure reaction in the auto-tandem amination (inter- and intramolecular Pd-catalyzed amination) of 2,3-dibromopyridine with amino(benzo)(di)azines and 2-chloro-3-iodopyridine with amino(benzo)(di)azines, respectively. Depending on the substrate a Pd-catalyzed amination, a base-assisted nucleophilic aromatic substitution or?a combination of both is occurring. An explanation based on the aromaticity of the amidine, supported by theoretical calculations, is provided. In addition we gained evidence that the intramolecular metal-catalyzed amination of N-(3-bromopyridin-2-yl)azaheteroarylamines and N-(2-chloropyridin-3-yl)azaheteroarylamines indeed involves a nitrogen atom that is not substituted with a hydrogen atom.
Orthogonal and auto-tandem catalysis: Synthesis of dipyrido[1,2-a:2′, 3′-d]imidazole and its benzo and aza analogues via inter- and intramolecular C-N bond formation
Loones, Kristof T. J.,Maes, Bert U. W.,Meyers, Caroline,Deruytter, Joke
, p. 260 - 264 (2006)
The synthesis of dipyrido[1,2-a:2′,3′-d]imidazole and hitherto unknown benzo and aza analogues is described. These relatively complex polycyclic heterocycles could be smoothly prepared in one step from commercially available building blocks. Mechanistically, the developed procedure involves orthogonal (Pd and Cu catalyst) or auto-tandem (Pd catalyst) catalysis via regioselective inter- and intramolecular C-N bond formation.
Synthesis of pyrido[3′,2′:4,5]imidazo[1,2-a]pyridines by reductive cyclisation of pyridinium salts
Begunov, Roman S.,Ryzvanovich, Galina A.,Nozdracheva, Ol'ga I.
, p. 119 - 120 (2006)
The reduction of N-(3-nitro-2-pyridyl)pyridinium chlorides by SnCl 2 resulted in the formation of pyrido[3′,2′:4,5] imidazo[1,2-a]pyridines or N-(3-anuno-2-pyridyl)-3,5-dimethylpyridinium chloride depending on the structure of the substrate.
Synthesis of azinoazole structural isomers by photocyclization
Frolov
, p. 883 - 886 (2007/10/03)
Irradiation of 2-chloro-N-(pyridin-2-yl)pyridin-3-amine and N-(2-chloropyridin-3-yl)-4,6-dimethyl-pyrimidin-2-amine in aqueous-alcoholic solution gave new azinoazole derivatives, 6-chlorodipyrido-[1,2-a:5′, 4′-d]imidazole and 1,3-dimethylpyrido[3′,2′:4,5]imidazo[1,2-a] pyrimidine, respectively. Pleiades Publishing, Inc., 2006.
Aminoimidazo[1,2-a]pyridines: Regioselective synthesis of substituted imidazonaphthyridines, azacarbolines and cyclazines
Chezal, Jean M,Moreau, Emmanuel,Chavignon, Olivier,Gaumet, Vincent,Métin, Jacques,Blache, Yves,Diez, Anna,Fradera, Xavier,Luque, Javier,Teulade, Jean C
, p. 295 - 307 (2007/10/03)
In order to study the regioselectivity of thermal cyclocondensation, aminoimidazo[1,2-a]pyridines (AIP) 5a-e were prepared, further converted into iminophosphoranes 7a-e, and ultimately converted regioselectively in angular annulated imidazonaphthyridines (IN) 8a, 10a, 11a, 12a or linear annulated dipyridoimidazole (DPI) 17a. From 2-substituted derivative 23, the peri annulated product 24a was obtained. The starting amines 5a-f reacted with aldehydes to yield regioselectively IN 8a-c, 10a-c, 11a-c, 12a,b, DPI 16a-e, 17a-d and TIBO like structures (±)-13 and 24a-c, as proved by X-ray analysis. The 1,2- or 1,4-addition between amines and α,β-unsaturated aldehydes concerning the pyridine and imidazole moieties is discussed in the light of these results.
