Selenium bases

The use of high purity selenium in digital imaging is considered a potential market. Selenium-based plates can be used to replace conventional silver-based x-ray film, and in 1994 the Xerox Corporation introduced a selenium-based product, Verdefilm, for use in graphic arts appHcations. 

Shaporenko, A., Muller, J., Weidner, T, Terfort, A. and Zharnikov, M. (2007) Balance of Structure-Building Forces in Selenium-Based Self-Assembled Monolayers. Journal of the American Chemical Society, 129, 2232-2233. 

Like sulfur, selenium based electron donors are heavily studied due to their potential as antithyroid agents. Of the 28 complexes reported, the majority (20) are diiodine based, and most of these (16) are simple adducts. One diiodine complex is bridged, one contains only extended adducts, one contains only bridged adducts, and one contains both bridged and extended adducts. All of the interhalogen complexes are simple adducts except one with iodine monobromine, which forms an extended adduct. 

Deacon, A. M. and EaUck, S. E. (1999). Selenium-based MAD phasing setting the sites on larger structures. Structure Fold Des. 7, R161-166. 

TOF Measurements in Selenium-Based Amorphous Multilayer Photoconductors 66... 

Selenium-based reactions are generally very mild, often with the advantage of preparing the selenium derivative and carrying out the oxidative elimination as a one-pot sequence. 

Figure 9.3. Transformations of a carbohydrate attached to cross-linked polystyrene by a selenium-based linkage [15].

The crystal structure of the gallate salt 48 of the selenium-based cation [49]+ has been determined by single crystal X-ray diffraction <2005IC1837>. Summaries of pertinent intramolecular and intermolecular distances are provided in Table 18. The crystal structure of the salt 48 consists of cations [49]+ and anions [GaCU]- oriented so as to allow a pair of close intermolecular Cl—Se contacts. In addition, there is a third contact (Cl(3)—Se(l )) to the anion located above the molecular plane. The cations, which are planar to within 0.021(4)A, adopt a head-to-tail 7i-stacked arrangement running parallel to the jc-direction. The interplanar separation within the head-to-tail pairs is... 

Another example of the resin-capture-release technique which should see widespread applications in the future is the selenium-mediated functionalization of organic compounds. Polymer-supported selenium-derived reagents [34] are very versatile because a rich chemistry around the carbon-selenium bond has been established in solution and the difficulties arising from the odor and the toxicity of low-molecular weight selenium compounds can be avoided. Thus, reagent 26 (X = Cl) was first prepared by Michels, Kato and Heitz [35] and was employed in reactions with carbonyl compounds. This treatment yielded polymer-bound a-seleno intermediates, which were set free back into solution as enones from hydrogen peroxide induced elimination. Recently, new selenium-based functionalized polymers 26 (X = Br)-28 were developed, which have been utilized in syntheses according to Scheme 11 (refer also to Scheme 3) [36],... 

Recently, Wirth and Uehlin further extended the selenium-based solid-phase assisted chemistry by introducing a new polymer-bound chiral selenium electrophile 29. Regio-and stereoselective 1,2-methoxyselenylation of propenylbenzene gave intermediate adduct 30 which was cleaved by oxidative elimination via the selenoxide to yield the corresponding allylmethyl ether (Scheme 12) [38]. 

Synlett 1999, 1802-1804 d) Selenium-based linker K. C. Nicolaou, H. J. Mitchell, K. C. Fylaktakidou, et al., Angew. Chem. 2000, 112, 1089-1093 e) Ether-type linker K. Fukase, Y. Nakai,... 

Nicolaou KC, Pfefferkorn JA, Cao GQ, Selenium-based solid-phase synthesis of benzopyrans. I Applications to combinatorial synthesis of natural products, Angew. Chem., Int., Ed. Engl., 39 743-739, 2000. 

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