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An alternative method for forming sulfonates through hypervalent iodine(III) reagent-mediated oxidation of sodium sulfinates has been developed. This transformation involves trapping reactive sulfonium species using alcohols. With additional optimization of the reaction conditions, the method appears extendable to other nucleophiles such as electron-rich aromatic systems or cyclic ethers through a ring opening pathway.

A rapid route to 5,5- and 5,6- bicyclic systems is provided by an 1,3-alkyl-shift process mediated by a hypervalent iodine reagent on aromatics. The structures obtained contain several unsaturations with different behaviors and reactivities. Such diversity allows further elaborations for the rapid formation of compact systems present in a variety of natural products. The potential for further transformations has been demonstrated by performing a double Michael addition. This cyclization process is regio- and stereoselective due to the presence of a former benzylic substituent. Furthermore, an extension of this approach has been accomplished on indole derivatives.

A rapid route to 5,5- and 5,6- bicyclic systems is provided by an 1,3-alkyl-shift process mediated by a hypervalent iodine reagent on aromatics. The structures obtained contain several unsaturations with different behaviors and reactivities. Such diversity allows further elaborations for the rapid formation of compact systems present in a variety of natural products. The potential for further transformations has been demonstrated by performing a double Michael addition. This cyclization process is regio- and stereoselective due to the presence of a former benzylic substituent. Furthermore, an extension of this approach has been accomplished on indole derivatives.

In an effort to develop an improved medium for optical communication, chalcogenide glasses are being investigated for waveguide and integrated optical components. These glasses are attractive for integrated optics applications due to their good infrared transmission and high nonlinear Kerr effects. The fact that these glasses can be fabricated in thin films and optical fiber forms constitute a major advantage for future high-speed optical devices applications. However, to advance these novel characteristics, it is crucial to identify the structure/property relationship in the glass, in both bulk and film materials. Rutherford Backscattering Spectroscopy (RBS) is an analytical tool that gives very useful information regarding compositional and structural analysis of the films, as well as a precise measurement of the film's layer thickness. Results obtained showed no apparent variation in composition and small (less than 10%) density variation in single layer As2S3 films. Multilayer films, which thickness were measured using SEM images, displayed compositional and density modifications associated with the annealing process. The same calculations were conducted after almost a year from the previous measurements to study changes induced due to film aging. Stoichiometric and thickness modifications, caused by aging, were observed in unannealed structures. No apparent changes were detected in annealed films. Waveguide Raman Spectroscopy was used as a complementary tool to identify the molecular features responsible for the changes.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.