Supported phosphotungstic acid catalyst on modified activated carbon for Friedel-Crafts alkenylation of diverse aromatics to their corresponding α-arylstyrenes

The supported phosphotungstic acid catalysts on modified activated carbon (PTA/AC) prepared by a facile wet impregnation method were employed for Friedel-Crafts alkenylation of diverse aromatics with phenylacetylene to synthesize their corresponding alpha-arylstyrenes. Reaction results demonstrate that the fabricated PTA/AC catalyst with 30 wt.% PTA loading exhibits outstanding catalytic performance. The 100% conversion of phenylacetylene with 95.7% selectivity towards alpha-(2,5-dimethylphenyl) styrene can be achieved over the developed 30 wt.% PTA/AC catalyst under optimized reaction conditions, and no visible loss in catalytic performance can be observed after it suffers from several times recycling. The various characterization techniques including X-ray diffraction, N-2 adsorption-desorption, Fourier transform infrared spectroscopy, and NH3 temperature-programmed desorption were employed to reveal the relationship between the catalysts nature and catalytic properties. Moreover, the results on the scope of aromatics for the Friedel-Crafts alkenylation illustrate that the developed PTA/AC alkenylation catalyst can be efficiently catalyze the diverse aromatics and even for the electron deficient chlorobenzene. The developed PTA/AC catalyst, using the modified low-cost and sustainable AC as support, may be a robust and promising candidate for highly-efficient and clean a-arylstyrenes production through Friedel-Crafts alkenylation of diverse aromatics including electron-donating and electron-withdrawing groups substituted benzene derivatives as well as heterocyclic and polypolycyclic arenes with phenylacetylene. (C) 2015 Elsevier B.V. All rights reserved.