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Showing 1 to 20 of 120 for “"Acid-Catalyzed"”.
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Borinic Acid-catalyzed Ring-opening of Epoxy Alcohols
Borinic acid catalysis has been used by our group to effect ring-opening and rearrangement reactions of 2,3-epoxy alcohols via reversible borinate ester formation. This work focuses on expanding the mode of borinic acid catalysis to the activation of 3,4-epoxy alcohols for regioselective …
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Brønsted acid-catalyzed alkylation of tetrazoles with alcohols
… alkylating reagents. While Lewis and Brønsted acid-catalyzed alkylations of tetrazoles using alcohols have been reported, their drawbacks include the necessity to use excess of strong Brønsted acid, narrow scope, long reaction time and poor functional group tolerance. Recently, we developed a …
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Brønsted Acid Catalyzed Carbon-Carbon Bond Forming Reactions
… of new methodology in the field of Brønsted acid catalysis enabling rapid synthesis of medicinally relevant compounds. It is foreseen that small molecule sulfonic acids evaluated in this research project will unveil new asymmetric carbon carbon bond forming reactions between substrates …
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Brønsted acid-catalyzed stereoselective allylation of exo-glycals with allyltrimethylsilane
… using allyltrimethylsilane. This Brønsted acid-catalyzed transformation for the preparation of C,C-glycosides occurs readily in the presence of a tetrafluoroboric acid diethyl ether complex. In contrast to previously reported procedures, this reaction proceeds in a diastereoselective manner …
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Brønsted acid-catalyzed reaction of alkynyltrifluoroborates with acetals and ketals
… in synthetic organic chemistry. Brønsted acid catalysis is a powerful synthetic tool to make many different compounds, however, the current carbon-based nucleophiles are the major limitation of acid-catalyzed reactions. In effort to expand repertoire of Brønsted acid compatible …
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Brønsted Acid-Catalyzed Reactions of Vinylboronic Acids and Benzhydryl Alcohols
… on harsh reaction conditions or the use of Lewis acid catalysts, which leads to low functional group tolerance. Herein, a methodology for the formation of 1,3,3-triphenylpropene derivatives through a Brønsted acid-catalyzed reaction of styrylboronic acids and benzhydryl alcohols is reported. The …
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Mechanisms of Methoxide Ion Substitution and Acid- Catalyzed Z/E Isomerization of N-Methoxyimines
… ethyl cyanoacetate, and diethyl malonate. Acid-catalyzed isomerization of compounds containing the O-methyloxime moiety have been investigated with ab initio calculations (HF/6-31+G*, MP2/6- 31+G*//HF/6-31+G*, B3LYP/6-31+G*//HF/6-31+G*). Barriers for rotation around the C-N bond following …
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Direct Brønsted acid-catalyzed functionalization of benzhydryl alcohols and 2-ethoxytetrahydrofuran using potassium trifluoroborate salts
… expensive and sensitive transition metals. Lewis acid-catalyzed reactions involving organotrifluoroborates have emerged as an alternative to metal-catalyzed protocols. However, these methods rely on generating unstable boron dihalide species thereby resulting in low functional group tolerance. A …
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The acid-catalyzed self-condensation reaction of b-diketones in the presence of 2,2,2-trifluorodiazoethane
A novel acid-catalyzed self-condensation reaction of 6-diketones in the presence of 2,2,2-trifluorodiazoethane (TFD) has been discovered. This reaction is of interest because not many methods are available for the preparation of cyclized products (e.g., aromatic natural products) from 6-dicarbonyl …
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DEVELOPMENT OF METAL-CATALYZED REACTIONS OF ALLENES WITH IMINES AND THE INVESTIGATION OF BRΘNSTED ACID CATALYZED ENE REACTIONS
… reaction for the generation of unnatural amino acids containing densely functionalized alkenes and allene moieties. In addition to studying new reactions, we have worked on the further development of the established ene reaction. The ene reaction is one of the most powerful carbon–carbon …
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Harnessing cheminformatics for catalyst design I. Investigation into a general, asymmetric synthesis of cinchona alkaloid analogs towards asymmetric phase transfer II. Development of an enantioselective brønsted acid catalyzed four-component Ugi reaction
… studied against an asymmetric phase transfer catalyzed cyclopropanation reaction. Second, (R)-BINOL derived phosphoric acids were studied in regards to the brønsted acid catalyzed Ugi reaction. In regards to Cinchona alkaloids, the concentration was first on methodology develop to rapidly …
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Photobenzidine rearrangement: Photodecomposition of N.N'-dimethylhydrazoaromatics and 1,4-dialkyl-1,4-diphenyl-2-tetrazenes
Acid-catalyzed and thermal rearrangements of hydrazoaromatics have been well documented; however, little is known about light-2 induced benzidine rearrangements^ Weiss reported that azobenzene and aniline were formed in the photolysis of an alcoholic solution of hydrazobenzene with a mercury lamp. …
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Characterization of Solution Species Relevant to the Peroxidase-Nadh Biochemical Oscillator
… of kinetics of simultaneous processes of NADH acid-catalyzed decomposition, complexation, and oxidation in different environments were undertaken. It was observed that Fe2+ and Fe3+ were the only solution ions which caused a decrease in NADH decomposition rates, opposite to all other metal ions …
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On the Stereochemistry of Allylmetal-Aldehyde Condensations (Allyltrimethylsilane, Allyltributylstannane, Homoallylic Alcohols)
… of double bonds was observed with the Lewis acid catalyzed reaction of 3a. The selectivity for 4 was dependent on Lewis acid. Cyclization induced by fluoride ion resulted in a stereochemical reversal. The Lewis acid and heat induced cyclization of 3b gave a large preference for the syn isomer …
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Advancements in the diastereoselective synthesis of acyl pyrrolidines via the tandem aza-Cope—Mannich cyclization pathway
<p>We have developed a Lewis-acid catalyzed, diastereoselective aza-Cope rearrangement— Mannich cyclization to form acyl pyrrolidines from conformationally mobile substrates. In earlier studies from our lab, Brønsted acid-catalyzed reactions to form the same acyl pyrrolidines resulted in …
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