Initial Examinations of the Diastereoselectivity and Chemoselectivity of Intramolecular Silyl Nitronate [3+2] Cycloadditions with Alkenyl/Alkynyl Nitroethers.

This study examined the chemoselectivity and diastereoselectivity of silyl nitronate alkenyn-nitroethers in Intramolecular Silyl Nitronate Cycloadditions (ISNCs) to produce isoxazole derivatives with interesting medicinal properties. These reactions resulted in the formation of either dihydrofuro[3,4-c]isoxazolines/isoxazolidines and/or alkynyl moieties attached to 2,5-dihydrofuryl carbonyls. This study also discerned the diastereoselectivities of the resulting cyclic adducts and compared them to previous findings.

Lead/Drug Discovery from Natural Resources.

Natural products and their derivatives have been shown to be effective drug candidates against various diseases for many years. Over a long period of time, nature has produced an abundant and prosperous source pool for novel therapeutic agents with distinctive structures. Major natural-product-based drugs approved for clinical use include anti-infectives and anticancer agents.

Pentiptycene-Derived Fluorescence Turn-Off Polymer Chemosensor for Copper(II) Cation with High Selectivity and Sensitivity.

Fluorescent conjugated polymers (FCPs) have been explored for selective detection of metal cations with ultra-sensitivity in environmental and biological systems. Herein, a new FCP sensor, tmeda-PPpETE (poly[(pentiptycene ethynylene)--(thienylene ethynylene)] with a ,,'-trimethylethylenediamino receptor), has been designed and synthesized via Sonogashira cross-coupling reaction with the goal of improving solid state polymer sensor development. The polymer was found to be emissive at ~ 459 nm under UV radiation with a quantum yield of 0.

Electrically conducting polymers as templating interfaces for fabrication of copper nanotubes.

Submicrometer tubes have been fabricated by a polymer-based template approach using electroless deposition. The copper was deposited on polystyrene fibers functionalized with an interfacial electrically conducting polyaniline thin film layer. Thermal degradation of the functionalized fiber templates resulted in copper tubes of diameter 1600 ± 50 nm with wall thicknesses ranging between 100 and 200 nm.

Synthesis of novel 2H,5H-Dihydrofuran-3-yl Ketones via ISNC reactions.

Unique 1-[2H,5H-dihydrofur-3-yl]ketones have been synthesized from propargylic nitroethers via intramolecular cycloadditions involving silyl nitronates. Various substituent groups were placed on the 2 and 5 positions of the dihydrofuran rings. We examined the scope of the long-range coupling in proton NMR of the oxo-dihydrofuran products.