Browsing by Department "Chemistry"
Now showing items 1-20 of 23
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Attempted Synthesis of Casbene by Intramolecular Cyclopropanation
(ARKIVOC;, 2002-11-14)The antifungal diterpene casbene has been prepared in low yield by intramolecular cyclopropanation of the vinyldiazomethane reactant formed from geranylgeraniol. Careful analysis of the reaction mixture revealed relatively ... -
Cambridge Structural Database (WebCSD)
(2019-08-20) -
Challenges in the Highly Selective [3+1]-Cycloaddition of an Enoldiazoacetamide to Form a Donor–Acceptor cis-Cyclobutenecarboxamide
(Molecules;, 2021-06-09)A substituted donor–acceptor cyclobutenecarboxamide is synthesized with modest enan tiocontrol through a chiral copper(I) complex catalyzed [3 + 1]-cycloaddition reaction of α-acyl diphenylsulfur ylides with 3-siloxy-2-d ... -
Chemoselectivity in Dirhodium(II) Catalyzed Reactions of Diazoacetoacetates Prepared from α,β-Unsaturated Ketones
(ARKIVOC;, 2010-01-01)-Diazo β-keto esters from zinc triflate catalyzed Mukaiyama-Michael reactions between α,β unsaturated ketones and α silyloxyvinyldiazoacetates are valuable synthons for the synthesis of compounds that can be accessed through ... -
Chiral donor−acceptor azetines as powerful reactants for synthesis of amino acid derivatives
(Nature Communications;, 2019-11-22)Coupling reactions of amines and alcohols are of central importance for applications in chemistry and biology. These transformations typically involve the use of a reagent, activated as an electrophile, onto which nucleophile ... -
Cycloaddition reactions of enoldiazo compounds
(Chemical Society Reviews;, 2017-07-20)Enoldiazo esters and amides have proven to be versatile reagents for cycloaddition reactions that allow highly efficient construction of various carbocycles and heterocycles. Their versatility is exemplified by (1) ... -
Electrophilic Metal Carbenes as Reaction Intermediates in Catalytic Reactions
(Accounts of Chemical Research;, 1986-11-01) -
Enantioselectivity for Catalytic Cyclopropanation with Diazomalonates
(ARKIVOC;, 2003-03-24)The use of chiral azetidinone-ligated dirhodium(II) catalysts activates dinitrogen extrusion from diazomalonates and provides access to cyclopropanation products with selectivities as high as 40-50% ee. -
Formal [4+4]-, [4+3]-, and [4+2]-Cycloaddition Reactions of Donor-Acceptor Cyclobutenes, Cyclopropenes and Siloxyalkynes Induced by Brønsted Acid Catalysis
(Chemical Science;, 2021-02-18)Brønsted acid catalyzed formal [4 + 4]-, [4 + 3]-, and [4 + 2]-cycloadditions of donor–acceptor cyclobutenes, cyclopropenes, and siloxyalkynes with benzopyrylium ions are reported. [4 + 2]-cyclization/deMayo-type ring-extension ... -
Highly Efficient Olefin Isomerization Catalyzed by Metal Hydrides Derived from Dirhodium(II) Carboxylates and Catecholborane
(Main Group Metal Chemistry;, 1994-07-01)Dirhodium(ll) tetraacetate in combination with catecholborane catalyzes the isomerization of alkenes and dienes. Effective isomerization occurs at 80-135°C with the use of only 0.1 mol % rhodium acetate. With 2-methyl-1, ... -
Highly selective acylation of polyamines and aminoglycosides by 5-acyl-5-phenyl-1,5-dihydro-4H-pyrazol-4-ones
(Chemical Science;, 2017-08-30)5-Acyl-5-phenyl-1,5-dihydro-4H-pyrazol-4-ones, accessible from arylpropargyl phenyldiazoacetates, are highly selective acyl transfer reagents for di- and polyamines, as well as aminoalcohols and aminothiols. As reagents ... -
Imaging MS with MS
(2021-04-08) -
Kinetics and Mechanism of the Oxidation of Human deoxyHemoglobin by Nitrites
(Journal of Biological Chemistry;, 1981-12-10)The reactions of human hemoglobin with sodium nitrite and ethyl nitrite in deoxygenated media have been examined in kinetic detail. Nitrous acid has been identified from kinetic pH dependence studies as the principal oxidant ... -
New Catalysts and Methods for Highly Enantioselective Metal Carbene Reactions
(Pure and Applied Chemistry;, 1998-01-01)Asymmetric catalysis of metal carbene transformations with unique chiral dirhodium(I1) carboxamidates provides highly enantioselective, diastereoselective, and regioselective syntheses of lactones and lactams via ... -
On the Origin of the Conformationally Non-Interconvertable Isomers of Bisphenyldirhodium(III) Caprolactamate
(Journal of the Mexican Chemical Society;, 2009)A plausible explanation for the unprecedented formation of two conformational isomers of bisphenyldirhodium(III) caprolactamate is presented. The presence of acetic acid during the coupling process leading to the formation ... -
Oxidation of Deoxyhemerythrin to the Semi-Met Level by Nitrite
(Journal of Biological Chemistry;, 1984-10)In anaerobic phosphate buffer, pH 6.3-7.5, deoxyhemerythrin is oxidized to semi-methemerythrin (semi-met) by excess sodium nitrite. This oxidation is quantitative as judged by EPR spectroscopy. Further oxidation to ... -
Oxidation of Hemoglobin and Myoglobin by Alkyl Nitrites. Inhibition by Oxygen
(Journal of Biological Chemistry;, 1981-12-10)The reactions of human hemoglobin and sperm whale myoglobin with ethyl nitrite under aerobic conditions have been examined in kinetic detail. Ethyl nitrite converts two equivalents of oxyhemoglobin or oxymyoglobin to ... -
Silver-Catalyzed Carbene Functionalization of Methane in Supercritical Carbon Dioxide
(ChemCatChem;, 2011-09-08)