Crafts Benzylation Of Benzene Research Articles

Synergistic catalysis of isolated Fe3+ and Fe2O3 on FeO /HZSM-5 catalysts for Friedel–Crafts benzylation of benzene

Abstract FeO x /HZSM-5 catalyst with 8 wt.% Fe-loading (8-FeZ) exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeO x /HZSM-5 catalyst with 2.5 wt.% Fe-loading (2.5-FeZ) because the synergistic catalysis between isolated Fe 3+ and superfine Fe 2 O 3 occurred on 8-FeZ in the reaction.

An Extremely Active Solid Acid Catalyst, Nafion Resin/Silica Composite, for the Friedel−Crafts Benzylation of Benzene and p-Xylene with Benzyl Alcohol

Nafion resin, a recently developed Nafion resin/silica composite, and triflic acid are very effective catalysts for the Friedel−Crafts benzylation of benzene (at 80 °C) and p-xylene (at 100 °C) with p-methylbenzyl alcohol under ambient pressure. The composite is nearly 2 orders of magnitude more active than plain Nafion resin beads and even more active than the strong triflic acid based on the same amount of acid groups in the catalysts. The commercial Amberlyst-15 resin catalyst and p-toluenesulfonic acid (p-TSA) are inactive catalysts. Flowing nitrogen through the reactor to carry out the byproduct water was found to be very beneficial for driving the benzylation reaction to completion.

Activation of Clayzic and its effect on the relative rates of benzylation of aromatic substrates

The effects of the activation of K10 montmorillonite supported zinc chloride (‘Clayzic’) by different methods on the reactivity of the catalyst in the Friedel–Crafts benzylation of benzene and halo-benzenes have been investigated. There is an optimum temperature for thermal activation in air at which point a rate enhancement, compared to unactivated Clayzic, in the benzylation of benzene of greater than 30 has been achieved. The rate limiting factor for these reactions is believed to be the ability of the aromatic substrate to enter the polar mesopores containing the active zinc ions in Clayzic, causing unexpected and activation-dependent rate trends to be observed. Activation of Clayzic is believed to reduce the polar nature of the pores, so aiding partitioning of the substrate into the catalyst.