Reaction of 3-azidoisoxazoles with active methylene compounds

3-Azidoisoxazoles react with various active methylene compounds (malononitrile, ethyl cyanoacetate and ethyl acetoacetate) in the presence of base to give hybrid isoxazole–triazole molecules in good to nearly quantitative yields. © 201

3,3-Diazidoenones-new types of highly reactive bis-azides. Preparation and synthetic transformations

The interaction of geminal dichlorovinylketones with sodium azide was investigated by NMR and DFT calculations. It was found that the corresponding geminal 3,3-diazidoenones are the resultant species. These highly reactive compounds can be trapped with cyclooctyne to form bis-triazolyl substituted enones. In the absence of a trapping agent, 3,3-diazidoenones do cyclize into 3-azidoisoxazoles with the elimination of molecular nitrogen. The versatile reactivity of the resultant azidoisoxazoles was demonstrated in reactions with phosphorus(iii) derivatives, Huisgen 1,3-dipolar cycloaddition and Dimroth cyclization to provide efficient access to a variety of valuable compounds. © 2019 the Partner Organisations

Significant impact of lanthanide contraction on the structure of the phenanthroline complexes

The structure of La, Nd, Eu and Lu complexes with N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarbox- amide ligand was examined using X-ray diffraction analysis. Due to the effect of lanthanide contraction, lutetium forms unique type of complex having the coordination number 9 in contrast to other 10-coordinated lanthanides. © 202

The impact of alicyclic substituents on the extraction ability of new family of 1,10-phenanthroline-2,9-diamides

Development of efficient extractants for the separation of actinides and lanthanides in the technologies of nuclear fuel cycle is one of the most urgent and complex tasks in modern nuclear energetics. New family of 4,7-dichloro-1,10-phenanthroline-2,9-dicarboxylic acid diamides based on cyclic amines was synthesized and shown to exhibit high selectivity in the La/Am pair separation (SF (Am/La ≈ 10)) and in the Am/Eu pair separation (SF (Am/Eu ≈ 12)). It was shown that pyrrolidine derived diamide is more efficient extractant for americium, curium and lanthanides from highly acidic HNO3 solution than its non-cyclic N,N,N′,N′-tetraalkyl analogues. The structures of synthesized compounds were studied in details by IR, NMR spectroscopy, and single crystal X-ray diffraction. According to spectroscopy data, incorporation of aromatic rings to the amide fragment of ligand leads to complex dynamic behavior in solutions what is believed to strongly affect the extraction ability of synthesized ligands. © 2020 The Royal Society of Chemistry

Structural Insight into Complexation Ability and Coordination of Uranyl Nitrate by 1,10-Phenanthroline-2,9-diamides

Reprocessing of spent nuclear fuel (SNF) is an important task in a frame of ecology and rational use of natural resources. Uranium, as the main component of SNF (>95%), can be recovered for further use as fresh nuclear fuel. To minimize an amount of solid radioactive waste generated during SNF reprocessing, new extractants are under investigation. Diamides of 1,10-phenanthroline-2,9-dicarboxylic acid are perspective tetradentate N-donor ligands that form strong complexes with f-elements, which are soluble in polar organic solvents. As an example of three ligands of this class, we conducted a comparative study and showed how the substituent in the amide functional group affects the extraction ability toward uranyl nitrate from nitric acid media. We have performed a careful study (NMR, FT-IR, XRD, RMC-EXAFS) of the structures of synthesized complexes of new ligands with uranyl nitrate and used quantum mechanical calculations to explain the discovered regularities through. © 2021 American Chemical Society