23574-81-4Relevant articles and documents
Pushing the Limits of Neutral Organic Electron Donors: A Tetra(iminophosphorano)-Substituted Bispyridinylidene
Hanson, Samuel S.,Doni, Eswararao,Traboulsee, Kyle T.,Coulthard, Graeme,Murphy, John A.,Dyker, C. Adam
, p. 11236 - 11239 (2016/07/06)
A new ground-state organic electron donor has been prepared that features four strongly π-donating iminophosphorano substituents on a bispyridinylidene skeleton. Cyclic voltammetry reveals a record redox potential of ?1.70 V vs. saturated calomel electrode (SCE) for the couple involving the neutral organic donor and its dication. This highly reducing organic compound can be isolated (44 %) or more conveniently generated in situ by a deprotonation reaction involving its readily prepared pyridinium ion precursor. This donor is able to reduce a variety of aryl halides, and, owing to its redox potential, was found to be the first organic donor to be effective in the thermally induced reductive S N bond cleavage of N,N-dialkylsulfonamides, and reductive hydrodecyanation of malonitriles.
Highly efficient one-pot amination of carboxylate-substituted nitrogen-containing heteroaryl chlorides via Staudinger reaction
Kandalkar, Sachin R.,Kaduskar, Rahul D.,Ramaiah, Parimi Atchuta,Barawkar, Dinesh A.,Bhuniya, Debnath,Deshpande, Anil M.
supporting information, p. 414 - 418 (2013/02/23)
An efficient one-pot method for the synthesis of tert-butyl 6-aminonicotinate (5) is described. The key transformation involves displacement of the chloro group in tert-butyl 6-chloronicotinate (2) with azide followed by a Staudinger reaction. The scope of this methodology is further extended for the synthesis of a series of carboxylate-substituted heteroaryl amines. In particular, we synthesized tert-butyl carboxylate-substituted amino-pyridine, -pyridazine, and -pyrazine. In addition to one-pot conversion, short reaction time, simplicity of operation, ease of purification, and good yields are the key advantages of this methodology.
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.
