1528-88-7Relevant academic research and scientific papers
Radical cations of aromatic selenium compounds: Role of Se···X nonbonding interactions
Singh, Beena G.,Thomas, Elizabeth,Sawant, Shilpa N.,Takahashi, Kohei,Dedachi, Kenchi,Iwaoka, Michio,Priyadarsini, K. Indira
, p. 9259 - 9265 (2013)
Selenium centered radical cations in aliphatic selenium compounds are stabilized by formation of two-center-three electron (2c-3e) hemi bonds either with nearby heteroatoms forming monomer radicals or with selenium atoms of the parent molecules forming dimer radicals. Such radicals in aromatic selenium compounds would generally be stabilized as monomers by the delocalization of the spin density along the aromatic ring. To test the assumption if aromatic selenides having Se···X nonbonding interactions can show different types of radical cations, we have performed pulse radiolysis studies of three structurally related aromatic selenium compounds and the results have been substantiated with cyclic voltammetry and quantum chemical calculations. The three aromatic selenium compounds have functional groups like -CH 2N(CH3)2 (1), -CH2OH (2), and -CH3 (3) at ortho position to the -SeCH3 moiety. The energy of Se···X nonbonding interactions (Enb) for these compounds is in the order 1 (Se···N) > 2 (Se···O) > 3 (Se···H). Radical cations, 1?+, 2?+ and 3?+ were produced by the one-electron oxidation of 1, 2 and 3 by radiolytically generated ?OH and Br2?- radicals. Results on transient spectra, lifetime, and secondary reactions of 1?+, 2?+, and 3?+ indicated that 1?+ shows a significantly different absorption spectrum, longer lifetime, and less oxidizing power compared to those of 2?+ or 3?+. Quantum chemical calculations suggested that 1?+ is stabilized by the formation of a 2c-3e bond between Se and N atoms, whereas 2 ?+ and 3?+ acquire stability through the delocalization of the spin density on the aromatic ring. These results provide evidence for the first time that stronger nonbonding interactions between Se···N in the ground state, facilitate the formation of stabilized radical cations, which can significantly influence the redox chemistry and the biological activity of aromatic selenium compounds.
Metal-Free Synthesis of Selenodihydronaphthalenes by Selenoxide-Mediated Electrophilic Cyclization of Alkynes
An, Shaoyu,Li, Pingfan,Zhang, Zhong
, p. 3059 - 3070 (2021/07/22)
A transition-metal-free, selenium mediated electrophilic cyclization reaction was realized through a one-pot procedure between simple alkynes and triflic anhydride-activated selenoxides to give selenium containing dihydronaphthalene products. This method gave good to very high yields for all products, including selenium-substituted phenanthrene, dihydroquinoline, 2H-chromene, and coumarin, which can be further transformed to other functionalized compounds.
Synthesis of arylselenide ethers by photoinduced reactions of selenobenzamide, selenourea and selenocyanate anions with aryl halides
Bouchet, Lydia M.,Pe?é?ory, Alicia B.,Argüello, Juan E.
experimental part, p. 969 - 972 (2011/03/20)
Selenobenzamide (-SeCNH(Ph), 1), selenourea ( -SeCNH(NH2), 2) and selenocyanate (-SeCN, 3) anions afford areneselenolate ions (ArSe-) under photostimulation in the presence of tert-butoxide or 2-naphthoxide ions as electron donors (entrainment conditions) in DMSO. In a 'one-pot' procedure, ArSe- anions can be trapped by a subsequent aliphatic nucleophilic substitution giving aryl methyl selenides in good to excellent yields (67-100%). This simple approach is compatible with electron-donating and electron-withdrawing substituents, such as nitro and carbonyl groups.
Reductive Cleavage of the Se-Si Bond in Aryiselenotrimethylsilanes: Novel Method for the Synthesis of Unsymmetrical Selenides
Zhang, Songlin,Zhang, Yongmin
, p. 350 - 351 (2007/10/03)
Arylseienotrimethylsilanes are reduced by samarium diiodide to yield samarium areneselenolates, which react with alkyl halidesto give unsymmetrical selenides.
