constructed from indoles and cyclohexanone derivatives using a combination of catalytic niobic acid-on-carbon (Nb2O5/C) and palladium-on-carbon (Pd/C) under heating conditions without any oxidants. The Lewis acidic Nb2O5/C promoted the nucleophilic addition of indoles to the cyclohexanones, and the subsequent dehydration and Pd/C-catalyzed dehydrogenation produced the 3-arylindoles. The additive 2
On the polarity of partially fluorinated methyl groups
作者:Quentin A. Huchet、Bernd Kuhn、Björn Wagner、Holger Fischer、Manfred Kansy、Daniel Zimmerli、Erick M. Carreira、Klaus Müller
DOI:10.1016/j.jfluchem.2013.02.023
日期:2013.8
A series of indole and 5-methoxyindole derivatives, substituted at C3 with n-propyl or 4-methylcyclohexyl scaffolds bearing varying degrees of fluorination of the terminal methyl group, have been prepared and studied. These compounds exhibit characteristic polarity patterns, measured either by log P or chromatographic capacity factors, which are consistent with the partially known lipophilicity pattern
In the absence of an external reductant, C3-cycloalkylated indole could be synthesized through reductive alkylation of indole with cyclic ketone using a sulfonyl-functionalized Brønsted acid ionic liquid as a catalyst. Water generated in the initial stage of the reaction played a key role in rendering the reductive coupling possible. The reaction proceeds most likely in a radical way.