Microwave-Assisted Nafion-H Catalyzed Friedel–Crafts Type Reaction of Aromatic Aldehydes with Arenes: Synthesis of Triarylmethanes
作者:Surya G. K. Prakash、Gabriella Fogassy、George A. Olah
DOI:10.1007/s10562-010-0406-0
日期:2010.9
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
Herein, we report the challenging and scantily explored Friedel-Crafts alkylation of electron-deficient arenes using a “catalyst activation” approach. Through strong hydrogen bonding with solvent hexafluoroisopropanol (HFIP) the Brønsted acidity of the catalyst is increased which stabilizes the transition states of the Friedel-Crafts reaction via concerted mechanism.