Title: Regioselective Electrophilic Aromatic Substitution Reactions over Reusable Zeolites
VOLUME: 10 ISSUE: 13
Author(s):Keith Smith and Gamal A. El-Hiti
Affiliation:Centre for Clean Chemistry,Department of Chemistry, University of Wales Swansea, Singleton Park,Swansea, SA2 8PP, UK.
Keywords:Styrene Oxide, hydrogen bromide scavenger, Bromination, Methanesulfonylation, HZSM-5
Abstract: Zeolite catalysts can play an important role in the development of greener organic syntheses through their abilities to act as heterogeneous catalysts, support reagents, entrain by-products, avoid aqueous work-ups and enhance product selectivities via shape-selectivity. We have shown that zeolites under modest conditions can have advantages in para-regioselective nitration, alkylation, acylation, methanesulfonylation and halogenation of aromatic compounds. They can also assist in the electrophilic rearrangement of aryloxiranes. The zeolites can be easily removed from reaction mixtures by filtration and regenerated by heating and can then be reused several times to give the same selectivity.
