33369-26-5Relevant articles and documents
Catalytic asymmetric tamura cycloadditions
Manoni, Francesco,Connon, Stephen J.
supporting information, p. 2628 - 2632 (2014/03/21)
In the presence of a novel, tert-butyl-substituted squaramide-based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products of significant synthetic interest with excellent enantio- and diastereocontrol. The methodology is of wide scope and encompasses both homophthalic and glutaconic anhydride derivatives, which lead to structurally diverse products. Glutaconic acid-derived anhydrides undergo a clean post-cyclization decarboxylation process which is not a feature of reactions involving homophthalic acid-derived anhydrides. The unusual influence of reaction temperature on diastereocontrol has been probed, with reactions occurring at 30 °C and -30 °C delivering products epimeric at one stereocenter only, in near optical purity. Squared away: The first strategy for bringing about enantioselective Tamura reactions is reported. In the presence of a squaramide-based catalyst, enolizable anhydrides react with alkylidene oxindoles to generate spirooxindole products with excellent enantio- and diastereocontrol. The methodology is of wide scope and leads to structurally diverse products.
Esters and amides of substituted pyrrole acetic acids
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, (2008/06/13)
Esters and amides of substituted pyrrole acetic acids are useful in the treatment of colonic polyps.
Process for producing substituted pyrroles
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, (2008/06/13)
An acid having a dissociation constant of at least 1.3×10-5 at 25° C. is used to enhance the yield of alkyl, 1,4-dialkyl-3-alkoxycarbonylpyrrole-2-acetate in the reaction of a chloromethyl alkyl ketone with a dialkyl acetone dicarboxylate and an alkylamine in a reaction medium comprising an organic solvent. The preferred acid is formic acid.
