2945-12-2Relevant articles and documents
Microwave-assisted nafion-H catalyzed friedel-crafts type reaction of aromatic aldehydes with arenes: Synthesis of triarylmethanes
Prakash, Surya G. K.,Fogassy, Gabriella,Olah, George A.
experimental part, p. 155 - 159 (2011/01/04)
A new solid acid Nafion-H, a perfluorinated sulfonic acid resin, catalyzed microwave-assisted synthesis of triarylmethanes is described. Various benzaldehydes react readily with arenes to provide the corresponding triarylmethanes in good to excellent yields. The reactions were carried out under solvent free conditions under microwave irradiation in a pressure vessel. The solvent free microwave irradiation methods appears to be an environmentally friendly synthetic protocol providing products in significantly shorter reaction times over traditional heating methods carried out in a pressure tube.
Synthesis of (p-Nitroaryl)diarylmethanes via vicarious nucleophilic substitution of hydrogen
Makosza,Surowiec,Voskresensky
, p. 1237 - 1240 (2007/10/03)
(p-Nitroaryl)diarylmethanes are readily prepared via vicariousm nucleophilic substitution of hydrogen in nitroarenes with carbanions of diarylmethyl p-chlorophenyl sulfide. These carbanions are efficient reagents for introduction of diarylmethyl substituents in the para position of nitroarenes via the VNS reaction. The reaction does not proceed ortho to the nitro group due to steric hindrances on the addition step.
First General Synthesis of (p-Nitroaryl)diarylmethanes via Vicarious Nucleophilic Substitution of Hydrogen
Katritzky, Alan R.,Toader, Dorin
, p. 4137 - 4141 (2007/10/03)
A general regiospecific method for the synthesis of (p-nitroaryl)diarylmethanes has been developed starting from diarylmethanols and 2- and/or 3-substituted nitrobenzenes. This utilizes the quantitative condensation between benzotriazole and diarylmethanols under acidic catalysis and in the presence of perfluorocarbon fluids, followed by vicarious nucleophilic substitution of the resulting diarylmethylbenzotriazoles upon nitrobenzenes in moderate to high yield, Oxidative nucleophilic substitution of hydrogen is observed as a side process. These vicarious nucleophilic substitutions complement Friedel-Crafts reactions for the synthesis of triarylmethanes.