Zeolite-catalysed rearrangements in organic synthesis

Fries rearrangement of phenyl acetate over sulfonic modified mesostructured SBA-15 materials

“…The replacement of these conventional catalysts by heterogeneous reusable acid catalysts is promoting an important effort in heterogeneous catalysis research, mainly in the field of zeolites. Zeolites [4][5][6][7][8][9][10] and other acid heterogeneous catalysts such as the sulfonic resin Nafion [9] have been studied as catalytic systems in the Fries rearrangement of phenyl acetate. Rapid deactivation observed in zeolites, either in gaseous or liquid phase, evidence the need for a greater size pore system.…”

Sulfonic acid-functionalized mesoporous silica (SBA-Pr-SO3H) as solid acid catalyst in organic reactions

“…has been achieved (Scheme 15) [134]. The arenesulfonic acid-centers located within the structure of SBA-15 show high catalytic performance as compared to other homogeneous [135] and heterogeneous acid catalysts [136][137][138][139][140]. This high activity is accompanied with a remarkable stability without leaching of sulfur species during the reaction.…”

Porous Catalytic Systems in the Synthesis of Bioactive Heterocycles and Related Compounds

“…For instance, the Claisen rearrangement of allyl aryl ethers 10 followed by intramolecular hydroxyalkylation of the resulting olefin afforded 2-methyldihydrobenzofuran (11) (Scheme 6) [55]. For instance, the Claisen rearrangement of allyl aryl ethers 10 followed by intramolecular hydroxyalkylation of the resulting olefin afforded 2-methyldihydrobenzofuran (11) (Scheme 6) [55].…”