Polystyrene supported Al(OTf)3: A stable, efficient, selective, and reusable catalyst for sulfonylation of arenes with sulfonic acids
Cross-linked polystyrene supported aluminium triflate (Ps-Al(OTf) 3) was found to be an efficient and chemoselective heterogeneous Lewis acid catalyst for the direct conversion of arenes to sulfones using sulfonic acids as sulfonylating agents. The solid acid catalyst is stable (as a bench top catalyst) and can be easily recovered and reused without appreciable change in its efficiency.
Boroujeni, Kaveh Parvanak
experimental part
p. 1887 - 1890
(2010/11/18)
Study of regioselective methanesulfonylation of simple aromatics with methanesulfonic anhydride in the presence of zeolite catalysts
Regioselective methanesulfonylation of simple aromatics using methanesulfonic anhydride can be achieved over zeolite catalysts. For example, methanesulfonylation of toluene over various cation-exchanged zeolite β catalysts affords higher para-selectivity in the synthesis of methyl tolyl sulfone than standard Friedel Crafts methanesulfonylation utilising aluminium chloride.
Smith, Keith,Ewart, Gordon M.,El-Hiti, Gamal A.,Randles, Kenneth R.
p. 3150 - 3154
(2007/10/03)
Total Synergistic effect between triflic acid and bismuth(IIIr antimony(III) chlorides in catalysis of the Methanesulfonylation of Arenes
A total synergistic effect between bismuth(III) or antimony(III) chlorides and triflic acid has been observed in the Friedel-Crafts methanesulfonylation of arenes and has resulted in the development of the first efficient catalytic systems usable for the methanesulfonylation of both activated and deactivated arenes. A proposed mechanism to explain the observed effects is also discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Friedel-Crafts sulfonylation of aromatics catalysed by solid acids: An eco-friendly route for sulfone synthesis
A mild and efficient catalytic method for Friedel-Crafts sulfonylation of arenes to the corresponding sulfones using a catalytic amount of reusable solid acid and arene- or alkanesulfonyl chlorides, sulfonic anhydrides and sulfonic acids as sulfonylating agents is described. Solid acids enable formation of a sulfone by the reaction of a sulfonic acid and an arene for the first time. In pursuit of the development of the best catalytic system, various metal-exchanged K10 montmorillonites and synthetic zeolites such as zeolite beta, zeolite Y and ZSM-5 have been screened for Friedel-Crafts sulfone synthesis. Fe3+-montmorillonite in the family of clays and zeolite beta in the family of zeolites exhibit higher activity. The activity is correlated to the presence of the right mix of Bronsted and Lewis acidic sites. The regioselective sulfonylation of toluene and naphthalene are studied in which para and beta selectivities are observed respectively. The Royal Society of Chemistry 2000.
Choudary, Boyapati M.,Chowdari, N. Sreenivasa,Kantam, M. Lakshmi
p. 2689 - 2693
(2007/10/03)
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