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Reactivity proton sponges

Sometimes a strongly hydrogen-bonded system, such as the fluori-nated proton sponge compound shown in Scheme 2.21, can have an impact on reactivity.25... [Pg.35]

Reactivity features of double and 2,7-disubstituted naphthalene proton sponges... [Pg.996]

When l,8-bis(dimethylamino)-4-vinylnaphthalene (121) is heated with 3,6-diphenyl-s-tetrazine (DFT), a [4 + 2]-cycloaddition reaction with reverse electron demands takes place to give the 1,4-dihydropyridazine derivative 208 (Scheme 37). The latter could be oxidized with chloranil or with excess of DFT to pyridazine 209118. A similar reaction with acenaphthylene proton sponge 107 gives directly the annelated pyridazine 139, since the intermediate dihydropyridazine is readily oxidized in air. It was established that the reactivity ratio of compounds 107, 121, 5-dimethylaminoacenaphthylene and acenaphthylene in the reaction with DFT is equal to 32 17 14 1, respectively. These data are in... [Pg.999]

The two parts of the present volume consist of 17 chapters written by experts from 10 countries. They start with historical background, followed by chapters on the theory, structure, thermochemistry, photophysics and photochemistry and electrochemistry of anilines, on their mass spectrometry, NMR spectra and analysis and on their modern syntheses by transition metal catalysed processes. Other chapters deal with their rearrangements, their reactivity as nucleophiles, their use as solvatochromic probes, their hydrogen bonded complexes, and their versatile uses in the chemical industry, and the relevant topic of toxicity and environmental aspects. A chapter on a special group of anilines—the proton sponges—ends the book. [Pg.1155]

Kiely and Guiry reported an asymmetric version of the intramolecular Heck reaction of aryl triflate [36]. In this reaction. Proton Sponge (1) also greatly improved the reactivity. [Pg.264]

The first highly enantioselective synthesis of the p-lactam ring with Cinchona alkaloids was demonstrated by Lectka and coworkers in 2000. They employed 10 mol% of benzoylquinine (O-Bz-Q) or benzoylquinidine (O-Bz-QD), to condense electron-deficient a-imino esters and ketenes (Scheme 15.12). To ensure in situ ketene formation (in fact a chiral ketene enolate is the reactive species.), proton sponge (PS) was used as a... [Pg.51]


See other pages where Reactivity proton sponges is mentioned: [Pg.1057]    [Pg.110]    [Pg.58]    [Pg.88]    [Pg.92]    [Pg.240]    [Pg.14]    [Pg.709]    [Pg.935]    [Pg.947]    [Pg.971]    [Pg.988]    [Pg.1000]    [Pg.91]    [Pg.353]    [Pg.92]    [Pg.256]    [Pg.265]    [Pg.673]    [Pg.170]    [Pg.71]    [Pg.100]    [Pg.3]   
See also in sourсe #XX -- [ Pg.935 ]




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