3316-11-8Relevant articles and documents
Merging supramolecular catalysis and aminocatalysis: Amino-appended β-cyclodextrins (ACDs) as efficient and recyclable supramolecular catalysts for the synthesis of tetraketones
Ren, Yufeng,Yang, Bo,Liao, Xiali
, p. 22034 - 22042 (2016/03/08)
Well-designed amino-appended β-cyclodextrins (ACDs) with an amino side chain of different lengths at the primary face of β-CD were synthesized and employed in the catalytic synthesis of a series of tetraketones as supramolecular catalysts in water for the first time. Yields of 58-97% were obtained with up to 30 examples of substrate. The catalyst could be recycled easily, while a 92% yield and 84% rate of catalyst recovery could be achieved after 8 cycles of catalyst recycling. Moreover, a catalytic mechanism merging supramolecular catalysis and aminocatalysis could be proposed through detailed 1D and 2D NMR, ESI-MS and Job plot analyses. This protocol retained the promising characteristics of ambient temperature, green medium, simple operation, broad substrate scope, excellent yields, superb catalyst recycling performance and unique catalytic mechanism.
Synthesis, characterization, and electrochemistry of some acridine-1,8-dione dyes
Srividya,Ramamurthy,Shanmugasundaram,Ramakrishnan
, p. 5083 - 5089 (2007/10/03)
The synthesis, characterization, and electrochemical behavior of some acridinedione derivatives are reported. Cyclic voltammetric studies show that all the dyes undergo irreversible oxidation irrespective of the substitution on the nitrogen. The product formed on oxidation is the aromatic derivative in the case of N-H compounds and the acridinium salt in the case of the N-substituted compounds, which have been isolated and characterized. Formation of an intermediate carbon-centered radical is observed as evidenced by ESR spin-trapping experiments. A mechanistic scheme for the electrochemical oxidation is proposed. On carrying out reduction after oxidation, different products are formed depending on the substitution on the nitrogen. There is no reduction of the oxidized product in the case of N-H compounds, and compounds with substitution on nitrogen undergo reduction consistent with the observation in N-alkylpyridinium salts.
Electrophilic Substitution in Pyrroles. Part 5. Reaction of Dipyrrylmethanes with Arenediazonium Ions
Butler, Anthony R.,Shepherd, Peter T.
, p. 113 - 116 (2007/10/02)
Dipyrrylmethanes react with arenediazonium ions in acid solution to form azopyrroles and formaldehyde.At low pH cleavage of the methylene bridge is brought about by attack of hydrogen ions, but at higher pH arenediazonium ions assume this role.In the reaction of benzylpyrrole, benzyl alcohol was detected as a product, suggesting formation of a benzyl carbonium ion.The relevance of these studies to the van den Bergh test for bilirubin is considered.
