NIR luminescent detection of quercetin based on an octanuclear Zn(ii)-Nd(iii) salen nanocluster.

A NIR luminescent octanuclear Zn(ii)-Nd(iii) nanocluster 1 was constructed by the use of a salen-type Schiff base ligand. 1 exhibits a lanthanide luminescent response to Que with high sensitivity. The quenching constant of Que to the lanthanide emission is 2.

Construction of a crystalline 14-metal Zn-Nd rectangular nanocluster with a dual-emissive response towards metal ions.

A crystalline 14-metal Zn-Nd cluster [ZnNdL(OAc)(O)(NO)(OCH)] (1) was constructed using a flexible Schiff base ligand with long-chain (CH)O(CH)O(CH) backbone. 1 exhibits a nanoscale rectangular structure (10 × 14 × 18 Å). Besides the visible ligand-centered emission, 1 displays typical NIR luminescence of Nd.

Design of a highly nanodispersed Pd-MgO/SiO(2) composite catalyst with multifunctional activity for CH(4) reforming.

We describe a highly nanodispersed Pd-MgO/SiO(2) composite catalyst synthesized by an in situ, one-pot, reverse microemulsion method as a multifunctional catalyst for low-temperature CH(4) reforming. Experimental results suggested evidence for a synergistic interplay of each component and DFT calculations confirmed a multifunctional reaction mechanism of CH(4) reforming and the importance of the Pd-MgO interface. We find that the Pd nanoparticle binds and dissociates CH(4), that MgO activates CO(2) and increases coking resistance, and that SiO(2) prevents Pd sintering.

Studies Toward the Syntheses of Pluramycin Natural Products. The First Total Synthesis of Isokidamycin.

We report the first total synthesis of the complex C-aryl glycoside isokidamycin, the epimer of the naturally-occurring pluramycin antibiotic kidamycin. The synthesis features a highly efficientDiels-Alder reaction between a substituted naphthyne and a glycosylatedfuran to form the anthracene core bearing a pendant angolosamine C-glycoside. The regiochemical outcome of the Diels-Alder reaction was controlled by employing a disposable silicon-tether to link the reactive napthyne and the glycosyl furan, rendering the cycloaddition intramolecular.

Iminium Ion Cascade Reactions: Stereoselective Synthesis of Quinolizidines and Indolizidines.

A novel iminium ion cascade reaction has been developed that allows for the stereoselective synthesis of a variety of substituted aza-fused bicycles. The combination of amino allylsilanes and aldehydes (or ketones) was used to synthesize a number of quinolizidines and indolizidines in an one-pot reaction sequence. This technology has been used to effect the facile syntheses of several indolizidine and quinolizidine natural products including, (±)-epilupinine, (±)-tashiromine, and (-)-epimyrtine.

The Pauson-Khand Reaction as a New Entry to the Synthesis of Bridged Bicyclic Heterocycles: Application to the Enantioselective Total Synthesis of (-)-Alstonerine.

The first application of the Pauson-Khand reaction (PKR) to the synthesis of azabridged bicyclic structures is described. Compounds containing azabicyclo[3.3.

Tandem Intramolecular Benzyne-Furan Cycloadditions. Total Synthesis of Vineomycinone B(2) Methyl Ester.

We have exploited tandem intramolecular benzyne-furan cycloadditions employing three different benzyne precursors to generate substituted bisoxabenzonorbornadienes in a single operation. The regiochemical outcomes in these Diels-Alder reactions were effectively controlled by using disposable silicon tethers to link the reacting benzynes and furan moieties. Two different methods for converting the intermediate bisoxabenzonorbornadienes to substituted anthrarufins were developed.