New heterogeneous catalysts for greener routes in the synthesis of fine chemicals

作者：Coman Simona M^*; Pop Georgeta; Stere Cristina; Parvulescu Vasile I; El Haskouri Jamal; Beltran Daniel; Amoros Pedro

来源：Journal of Catalysis, 2007, 251(2): 388-399.

DOI：10.1016/j.jcat.2007.08.001

• heterogeneous catalysis
• mesoporous structures
• tin triflate
• acylated sulfonamides
• (dl)-[alpha]-tocopherol

New strong Lewis acid SnTf-MCM-41 and SnTf-UVM-7 catalysts with unimodal and bimodal pore systems were prepared in a two-step synthesisin which the trillic acid (Tf) was incorporated to previously synthesized mesoporous tin-containing silicas. The Sn incorporation inside the pore walls was carried out through the Atrane method. The SnTf-UVM-7 catalysts were prepared by aggregating nanometric mesoporous particles defining a hierarchic textural-type additional pore system. Following these procedures, catalysts with different Si/Sn ratios-21.8 to 50.8 for SnTf-MCM-41 and 18.4 for SnTf-UVM-7-were prepared. These new materials were tested in the acylation of aromatic sulfonarnides using acetic acid as the acylating agent and in the synthesis of (dl)-[alpha]-tocopherol through the condensation of 2,3,6-trimethylhydroquinone (TMHQ) with isophytol (IP). The activity data indicate that these heterogeneous catalysts are very active, corresponding to high yields in acylated compounds as 65.5% and very high selectivity to (dl)-alpha]-tocopherol (94%, for a conversion of 98%).

• 出版日期2007-10-25