title: Selective synthesis of 6,8-di-t-butylated flavan over Zn-Al containing mesoporous silica catalysts.
abstract: We demonstrate a much green synthesis method for highly selective synthesis of 6,8-di-t-butylated flavan (6,8-DTBF) by liquid phase alkylation of 2,4-di-t-butylphenol (2,4-DTBP) with cinnamyl alcohol (Cin-OH) over mesoporous Zn-Al-MCM-41 catalysts synthesized under direct basic hydrothermal method. The main alkylated product, 6,8-DTBF is importantly used as an intermediate in the manufacture of biosynthetic organic compounds. The recyclable mesoporous Zn-Al-MCM-41 catalysts have also been reused in this reaction to study their catalytic activities. The influences of various reaction parameters such as temperature, time, ratios of reactant (2,4-DTBP-to-Cin-OH) have been extensively investigated for the synthesis of 6,8-DTBF. In addition, dimethyl sulfoxide (DMSO) has also been used as a solvent in this catalytic reaction. The mesoporous Zn-Al-MCM-41(75) gives excellent catalytic activity with 6,8-DTBF selectivity (86.0%) and 2,4-DTBP conversion (63.1%), and these catalytic results have also compared with that obtained using other mesoporous and microporous catalysts. On the basis of catalytic activity obtained by using the all catalysts, the Zn-Al-MCM-41(75) catalyst is found to be a highly active, recyclable and eco-friendly heterogeneous catalyst in the liquid-phase alkylation of 2,4-DTBP.
authors.affiliation: School of Chemical and Biomolecular Engineering, Pusan National University, Busan 609-735, Korea. chems@pnu.edu
authors.forename: M
authors.initials: M
authors.lastname: Selvaraj
authors.forename: P K
authors.initials: PK
authors.lastname: Sinha
authors.forename: D-W
authors.initials: DW
authors.lastname: Park
authors.forename: Il
authors.initials: I
authors.lastname: Kim
authors.forename: S
authors.initials: S
authors.lastname: Kawi
authors.forename: C S
authors.initials: CS
authors.lastname: Ha