1209458-62-7Relevant academic research and scientific papers
Access to 2-Aminopyridines - Compounds of great biological and chemical significance
Bolliger, Jeanne L.,Oberholzer, Miriam,Frech, Christian M.
, p. 945 - 954 (2011)
2-Aminopyridines are key structural cores of bioactive natural products, medicinally important compounds, and organic materials and thus, extremely valuable synthetic targets. The few reported 6-substituted 2-aminopyridines and the lack of flexible, efficient and general applicable methods for their synthesis demonstrates the urgent need of new methods for their preparation. Reactions between 2,6-dibromopyridine and primary or secondary, cyclic or acyclic, and aliphatic or aromatic amines were shown to selectively yield the respective 6-bromopyridine-2-amines in very high yields which were successfully used as substrates for subsequent C-C cross-coupling reactions. The recently introduced dichloro-bis[1-(dicyclohexylphosphanyl)piperidine]palladium (1) was used as catalyst for the cross-coupling of 6-bromopyridine-2-amines with arylboronic acids, diaryl- and dialkylzinc reagents or olefins and hence, is also an excellent C-C cross-coupling catalyst for this type of substrate. Moreover, all the reaction protocols presented were in each of the catalyses uniformly applied. The scope of both the amination and the cross-coupling reactions are well defined and allow one to simply adapt the reaction protocols directly to other amines and/or coupling partners and, thus, provide for the first time a very flexible and generally applicable reaction protocol to get access to 2-aminopyridines.
A practical synthesis of substituted 2,6-diaminopyridines via microwave-assisted copper-catalyzed amination of halopyridines
Mastalir, Matthias,Rosenberg, Egon E.,Kirchner, Karl
, p. 8104 - 8110 (2015)
A microwave assisted copper-catalyzed amination protocol is reported utilizing a series of 2,6-dihalo- and 2-amino-6-halo pyridine precursors. Using this procedure, selective substitution of one or two halogens by aryl or alkylamines was achieved within 2-6 h with temperatures between 80 and 225 °C affording 2,6-diaminopyridines in good to excellent isolated yields. The reaction allows easy variation between educts and different N-substitutions. The target compounds are valuable precursors for the synthesis of bis-phosphorylated 2,6-diaminopyridines which are used as PNP pincer ligands in transition metal complexes.
