A periodic mesoporous hybrid material with a built-in palladium complex: An efficient catalyst for the Suzuki coupling and alcohol oxidation

A new periodic mesoporous hybrid material with a built-in Pd-guanidine complex was synthesized in the presence of a structure-directing agent. The N-2 sorption, XRD and TEM characterizations revealed that this hybrid material had a large surface area (> 700 m(2) g(-1)), a narrow pore size distribution (centered at 2.7 nm), and a periodic 2D-hexagonal structure. FT-IR, solid state NMR and XPS investigations confirmed that palladium-guanidine complex was covalently integrated with the solid material. The solid material exhibited high activity for the Suzuki coupling reaction of various aryl bromides in an aqueous ethanol solution under air. Furthermore, it was found that the solid material worked well for the aerobic oxidation of benzylic alcohols under ambient pressure of O-2, affording over 99% selectivity. This catalyst could be reused 9 times without a decrease in selectivity. This study supplies a new periodic mesoporous hybrid material with a built-in active palladium sites, which may be applied to other catalytic reactions. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.