title: An efficient heterogeneous Cu-grafted mesoporous organosilicas nanocatalyst for two and three component C-S coupling reactions.
abstract: Furfural-imine functionalized mesoporous organosilica material has been synthesized by post-synthesis surface functionalization of 2D-hexagnoal mesoporous SBA-15 with organosilane precursor 3-aminopropyltriethoxy-silane (APTES) followed by Schiff-base condensation with furfural. On the other hand, furfural-imine functionalized MCM-41 has been synthesized by Schiff-base condensation of furfural and 3-aminopropyltriethoxy-silane (APTES) followed by its hydrothermal co-condensation with tetraethylorthosilicate (TEOS) in the presence of a cationic surfactant CTAB. Subsequent reaction of the imine-functionalized mesoporous organosilicas with Cu(OAc)2 in absolute ethanol produced Cu(II)-grafted mesoporous nanocatalysts 1 and 2, respectively. Powder XRD, HR TEM, FE SEM, N2 sorption and EPR experimental tolls are employed to characterize these Cu-grafted furfural-imine functionalized nanocatalysts. Cu-grafted MCM-41 (1) showed very good catalytic efficiency for the coupling of aryl bromides and thiophenol under aerobic conditions to produce different thioethers. On the other hand, Cu-anchored mesoporous SBA-15 nanocatalyst (2) exhibited high catalytic activity for one-pot three component coupling of different aryl halides with thiourea and benzyl bromide in aqueous medium to produce different aryl alkyl thioethers in very good yields. Both Cu-grafted mesoporous nanocatalysts can be efficiently reused for several reaction cycles.
authors.affiliation: Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur 700032, India.
authors.forename: John
authors.initials: J
authors.lastname: Mondal
authors.forename: Noor
authors.initials: N
authors.lastname: Salam
authors.forename: Asim
authors.initials: A
authors.lastname: Bhaumik
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D016062:Porosity; D012821:Silanes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: C509969:SBA-15; D012821:Silanes; D012822:Silicon Dioxide; D003300:Copper