Search

Your search keyword '"Klussmann, Martin"' showing total 283 results
Start Over Author "Klussmann, Martin"
283 results on '"Klussmann, Martin"'

8. Investigations of Pd-catalyzed ArX coupling reactions informed by reaction progress kinetic analysis

Author

Mathew, Jinu S., Klussmann, Martin, Iwamura, Hiroshi, Futran, Alan, Emanuelsson, Emma A.C., Valera, Fernando, and Blackmond, Donna G.

Subjects
Palladium -- Electric properties, Chemical reactions -- Research, Argon -- Electric properties, Biological sciences, Chemistry
Abstract

A series of examples from Pd-catalyzed coupling reactions of aryl halides are described to demonstrate how a wealth of kinetic information might be quantitatively determined even before proposing a reaction mechanism. To be considered plausible, any independent mechanistic proposal must be shown to be consistent with this global kinetic analysis.

Published
2006

11. Chemie, Köln und Karneval

Author

Breugst, Martin, primary, Bruns, Jörn, additional, Díaz Hernandez, Dolores, additional, Disch, Sabrina, additional, Klußmann, Martin, additional, Olthof, Selina, additional, and Strub, Erik, additional

Published
2020
Full Text
View/download PDF

22. Köln: Wissenschaft an Karneval

Author

Breugst, Martin, primary, Diaz-Hernandez, Dolores, additional, Disch, Sabrina, additional, Klußmann, Martin, additional, Prechtl, Martin, additional, Schlörer, Nils, additional, and Strub, Erik, additional

Published
2018
Full Text
View/download PDF

25. Emergence of solution-phase homochirally via crystal engineering of amino acids

Author

Klussmann, Martin, Izumi, Toshiko, White, Andrew J.P., Armstrong, Alan, and Blackmond, Donna G.

Subjects
Amino acids -- Chemical properties, Enantiomers -- Analysis, Chemistry
Abstract

A study report about the highly enantioenriched solutions of amino acids which might be prepared from nearly racemic mixtures by manipulation of amino acid phase behavior and provide a general and facile mechanism for evolution of homochirality is presented.

Published
2007

29. Probing the active catalyst on product-accelerated proline-mediated reactions

Author

Iwamura, Hiroshi, Wells, David H.,Jr., Mathew, Suju P., Klussmann, Martin, Armstrong, Alan, and Blackmond, Donna G.

Subjects
Catalysts -- Research, Amines -- Chemical properties, Chemical reactions -- Research, Chemistry
Abstract

The displacement by aldehyde from a hydrogen-bonded product-proline adduct, affording a catalytic cycle that circumvents free proline but retains other features central to the generally accepted enamine mechanism for proline catalysts. Circumventing free proline and incorporating hydrogen-bonded reaction helps to rationalize the observations of accelerating reaction rate in both the alpha-aminoxylation and alpha-amination reactions.

Published
2004

32. Investigating the Oxidation Step in the CuCl2-Catalyzed Aerobic Oxidative Coupling Reaction of N-Aryl Tetrahydroisoquinolines

Author

Boess, Esther, Van Hoof, Max, Birdsall, Sarah Luna, and Klussmann, Martin

Abstract

The oxidative coupling of N-aryl tetrahydroisoquinolines with nucleophiles has inspired the development of novel C–H functionalization reactions as well as mechanistic studies. Here, we investigate the oxidation step that forms iminium ions as key intermediates in the method using CuCl2as the catalyst and oxygen as the terminal oxidant. A strong electronic effect of substituents in the N-aryl ring was found by synthetic studies and a Hammett plot analysis, supporting initial electron transfer from the amine to Cu(II). The importance of the mechanism of oxidation on the substrate scope with differently substituted tetrahydroisoquinolines is discussed.

Published
2020
Full Text
View/download PDF

33. Molecular Radical Chain Initiators for Ambient‐ to Low‐Temperature Applications.

Author

Székely, Anna and Klussmann, Martin

Subjects
*RADICALS (Chemistry), *CHAIN initiation (Chemistry), *OXIDATION-reduction reaction, *INTERMEDIATES (Chemistry), *LOW temperatures
Abstract

An overview of methods for the initiation of radical chain reactions by specific initiator compounds, which generate radicals, is given. These can be utilized to initiate any kind of radical chain reaction by transforming substrates into the desired radical intermediates. Azo initiators, peroxides, nitroxides, trialkylboranes, dialkyl zinc compounds, and type I photoinitiators are discussed, as well as methods of redox‐ and sonochemical initiation. Methods of direct radical formation from the substrates, such as photoredox catalysis or high‐energy irradiation, are not included. The focus of this review lies on rather "low" temperatures in the range of 50 °C down to −78 °C, which can be useful to achieve more selective reactions. Illustrative applications of such radical chain initiators in a variety of reactions are discussed, including stereoselective ones and polymerizations. Radical, steady, go: Molecular radical chain initiators can initiate radical chain reactions by transforming substrates into the desired radical intermediates. The focus of this review lies on initiators for applications at rather low temperatures between 50 °C and −78 °C, which can be useful to achieve more selective reactions. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

34. An unusual metal-medicated formation of an asymmetrical carboxylate bridged dinuclear copper (II) complex

Author

Keutel, Heike, Seidel, Daniel, Klussmann, Martin, and Gorls, Helmar

Subjects
Copper -- Chemical properties, Hydrolysis -- Analysis, Chemistry
Abstract

The dinuclear copper complex (Cu, Cu) can be synthesized directly via the precursor (Cu) with Cu (ac)(sub 2) or alternatively via the trinuclear complex Cu [2(Cu)](sub 2). The formation of (Cu, Cu) is a copper medicated rearrangement and ester hydrolysis.

Published
2000

44. Alkenyl and Aryl Peroxides.

Author

Klussmann, Martin

Subjects
*CHEMICAL reactions, *CHEMISTRY, *ORGANIC chemistry, *HYDROGEN peroxide, *PEROXIDES
Abstract

Abstract: Alkenyl and aryl peroxides are a special class of organic peroxides. Under ambient conditions, they are usually short‐lived, rapidly decomposing into radicals by homolytic O−O bond cleavage. They play an important role in the chemistry of the lower atmosphere, where they are formed through ozonolysis of alkenes. In the dark, this pathway is considered the major source of hydroxyl radicals, the “detergent of the atmosphere”. In solution, alkenyl and aryl peroxides can be formed by various methods and their decomposition can be harnessed synthetically. For example, reactions involving alkenyl peroxides can be used to introduce ketones through radical additions, and nucleophilic aromatic substitution reactions generating aryl peroxides have been used to synthesize phenols. The radicals can also initiate radical polymerization reactions or chain reactions and mediate oxidative coupling by C−H bond functionalization. Knowledge of their chemistry could be helpful for projects generating or utilizing peroxides. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results