Thermal properties of azidohetarenes without reactive ortho-substituents, obtained by DSC analysis, were compared with the DSC data of ortho-phenyl and ortho-acyl substituted azidohetarenes, which give ring closure reactions either to indoles or to five-membered heterocycles such as isoxazoles. The reaction temperatures and reaction enthalpies give both information to prepare the reaction condi...

We disclose herein a highly enantioselective protocol for the Brønsted acid-catalyzed addition of indoles and phenols to in situ-generated ortho-quinone methides which deliver broadly substituted diarylindolylmethanes and triarylmethanes, respectively, in a one-pot reaction under very mild conditions. A chiral phosphoric acid catalyst has been developed for this process serving to convert the s...

We report here the first systematic study of nickel-catalyzed decarbonylation of aromatic aldehydes under relatively mild conditions. Aldehydes with electron donating groups at para and ortho positions are generally successful with our method. For aldehydes with electron-withdrawing groups, significantly higher yields were achieved for ortho-substituted substrates than para ones, probably due t...

(E)-Alkyl ortho-hydroxycinnamates cyclize to coumarins at elevated temperatures of 140-250 °C. We find that the use of tri-n-butylphosphane (20 mol %) as a nucleophilic organocatalyst in MeOH solution allows cyclization to take place under much milder conditions (60-70 °C). Several coumarins were prepared, starting from ortho-hydroxyarylaldehydes, by Wittig reaction with Ph(3)P=CHCO(2)Me to (E)...

Daidzein and genistein are two major components of soy isoflavones. They exist abundantly in plants and possess multiple bioactivities. In contrast, ortho-hydroxydaidzein (OHD) and ortho-hydroxygenistein (OHG), including 6-hydroxydaidzein (6-OHD), 8-hydroxydaidzein (8-OHD), 3'-hydroxydaidzein (3'-OHD), 6-hydroxygenistein (6-OHG), 8-hydroxygenistein (8-OHG), and 3'-hydroxygenistein (3'-OHG), are...

a simple extremely fast and efficient approach for the synthesis of substituted indazole ingood to excellent yield catalyzed by using silica sulfuric acid (ssa) in dmso solvent at roomtemperature. this is solid state reaction have been attracting the synthetic organic chemist asthey provided enhance reaction rates, less environmental pollution, greater selectivity, cleanerproducts and manipulat...

a new dimeric orthopalladated complex was synthesized via reaction of 2,3-dimethoxy benzaldehyde oxime with palladium chloride and lithium chloride in methanol as solvent and sodium acetate as base at room temperature. the catalytic activity of this dimeric [pd{c6h2(-ch=noh)-(ome)2-2,3}(µ-cl)]2 complex as an efficient, air, and moisture tolerant catalyst was investigated in mizoroki–heck cross ...

Recently, studies on the construction of 3D terrain modeling and location accuracy evaluation using UAV have been conducted, but application to coastal areas lacking image matching points has not made in detail yet. In topography survey UAV, ortho-images DSM (Digital Surface Model) data were constructed through imaging ground control point (GCP) surveying ground. case ortho-images, VRS was used...

BACKGROUND The present study was conducted to evaluate the effect of different topical agents utilized for prevention of enamel decalcification around orthodontic brackets bonded to bleached and non-bleached enamel. METHODS Human maxillary premolars (n = 120) were divided into two equal groups. Teeth in group I were left without bleaching while those in group II were bleached with Vivastyle g...