69982-02-1Relevant academic research and scientific papers
A Strategy to Aminate Pyridines, Diazines, and Pharmaceuticals via Heterocyclic Phosphonium Salts
Patel, Chirag,Mohnike, Margaret,Hilton, Michael C.,McNally, Andrew
, p. 2607 - 2610 (2018)
A straightforward process to aminate pyridines and diazines is presented by reacting phosphonium salt derivatives with sodium azide. The iminophosphorane products are versatile precursors to several nitrogen-containing functional groups, and the process can be applied to building block heterocycles, to drug-like fragments, and for late-stage functionalization of complex pharmaceuticals. Appealing features of this strategy include using C-H bonds as precursors, precise regioselectivity, and a distinct scope from other amination methods, particularly those relying on halogenated azaarenes.
Reaction between triphenylphosphine and aromatic amines in the presence of diethyl azodicarboxylate: An efficient synthesis of aryliminophosphoranes under neutral and mild conditions
Adib, Mehdi,Sheikhi, Ehsan,Deljoush, Azadeh
experimental part, p. 4137 - 4140 (2011/06/24)
An efficient synthesis of aryliminophosphoranes is described. A mixture of an aromatic amine, diethyl azodicarboxylate and triphenylphosphine undergo a Mitsonobu type reaction at ambient temperature in dry dichloromethane to afford aryliminophosphoranes in excellent yields.
Thermolysis of benzannulated enyne-carbodiimides. Application in the synthesis of pyrido[1′,2′:1,2]pyrimido[4,5-b]indoles and related heteroaromatic compounds
Lu, Xiaoling,Petersen, Jeffrey L.,Wang, Kung K.
, p. 7797 - 7801 (2007/10/03)
Several derivatives of the pyrido[1′,2′:1,2]pyrimido[4,5-b]indoles 4 and the pyrazino[1′,2′:1,2]-pyrimido[4,5-b]indoles 14 were synthesized by treatment of the benzannulated enyne-isocyanates 8 with the iminophosphoranes 9 and 13, respectively, for the aza-Wittig reaction followed by thermolysis. The reaction presumably proceeds through an initial formation of the corresponding benzannulated enyne-carbodiimides, such as 10, followed by a formal intramolecular hetero Diels-Alder reaction. Surprisingly, when the iminophosphorane 17 was used for condensation with 8, the expected pyrimido[1′,6′:1,2]pyrimido[4,5-b]indoles 16 were not obtained. Instead, the isomeric pyrimido[6′,1′:2,3]pyrimido[4,5-b]indoles 21 were isolated. Presumably, an alternative reaction pathway involving an initial [2 + 2] cycloaddition reaction to form 19 followed by ring opening could lead to 20 and, after an intramolecular radical-radical coupling, 21. Treatment of the urea derivatives 24 with dibromotriphenylphosphorane also produced in situ the benzannulated enynecarbodiimides 25, which on thermolysis gave the isoquinolino[2′,1′:1,2]pyrimido[4,5-b]indoles 26. Methylation of 4a, 14a, and 26a with methyl iodide occurred exclusively at the site of the indolo nitrogen. The planar geometry of those novel heteroaromatic compounds, resembling many DNA-binding agents, makes them potential candidates as DNA intercalators.
One-pot synthesis of novel (2-Oxo-1,2-dihydropyridin-3-yl)-1,3,5- triazine derivatives from methyl 2-(N- triphenylphosphoranylidene)aminonicotinate, aryl isocyanates and primary amines: Sequential aza-wittig /cycloaddition / ring-transformation reactions
Okawa, Tomohiro,Osakada, Naoto,Eguchi, Shoji,Kakehi, Akikazu
, p. 16061 - 16082 (2007/10/03)
(2-Oxo-1,2-dihydropyridin-3-yl)-1,3,5-triazine derivatives 10 were obtained unexpectedly, in stead of pyrido[2,3-d]pyrimidine derivatives, by the intermolecular aza-Wittig reaction of methyl 2-(N- triphenylphosphoranylidene)aminonicotinate 3 with aryl isocyanates followed by attempted heterocylization by use of prim-amines. A novel sequential aza- Wittig / cycloaddition / ring-transformation mechanism for the formation of 10 has been reported based on the isolation and characterization of the key intermediates, pyrido[1,2-a][1,3,5]triazines 15 formed via [4+2] cycloaddition of the initially produced carbodiimide with aryl isocyanates.
Dihalogentriphenylphosphoranes in the synthesis of heterocycles, 29. A simple synthesis of pteridin-4-ones, from methyl-3-amino-2-pyrazinecarboxylate and pyrazino[3,1]oxazin-4-ones
Wamhoff,Kroth
, p. 405 - 410 (2007/10/02)
Methyl 3-amino-2-pyrazinecarboxylate (3) affords the synthetically useful 3-aroylaminopyrazin-2-carboxylates 5a-f with aroyl chlorides, which are converted with dibromotriphenylphosphorane into 2-arylpyrazino[2,3-d][3,1]oxazin-4-ones 6a-f. Nucleophilic attack at the carbonyl function of these oxazinones results in ring cleaved amides which can be recyclized with dibromotriphenylphosphorane to afford 2-arylpteridin-4-ones 7a-f.
