A practical synthesis of substituted 2, 6-diaminopyridines via microwave-assisted copper-catalyzed amination of halopyridines. Issue 42 (21st October 2015)

• Record Type: Journal Article
• Authors: Mastalir, Matthias; Rosenberg, Egon E.; Kirchner, Karl
• Is Part Of: Tetrahedron. Volume 71:Issue 42(2015)
• Page Start: 8104
• Page End: 8110
• Publication Date: 2015-10-21
• Subjects: Aminations -- 2, 6-Diaminopyridines -- Nucleophilic aromatic substitutions -- Heterocycles -- Microwave assisted reactions -- Copper catalyzed; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2015.08.042
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: 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. Graphical abstract: A microwave assisted copper-catalyzed amination protocol is reported utilizing a series of 2, 6-dihalo- and 2-amino-6-halo pyridine precursors to yield 2, 6-diaminopyridines in good to excellent yields.