Abstract
Heterogeneous palladium catalysts were prepared by covalent immobilization of palladium (II) complexes of the general formula PdCl2L2 (L = P, CN) onto SBA-15 silica using a post-synthetic method. The state of the hybrid materials was characterized using a wide variety of molecular and solid-state techniques. In general, all the palladium modified solids exhibited highly ordered mesostructures while keeping the integrity of the parent molecular precursors. The catalytic performances of the materials were evaluated in the heteroannulation of 2-iodoaniline and 2-bromoaniline with triethyl(phenylethynyl)silane which showed high activities and selectivities with isolated yields in the range of 80-85%. Despite a decrease in the initial activity, quantitative conversion of iodoaniline to the expected product was observed over multiple recyclings, making these materials particularly efficient for such applications. The catalytic process was shown to be homogeneous in nature, the solid apparently serving as a "reservoir" for the metal between cycles.
Original language | English (US) |
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Pages (from-to) | 179-187 |
Number of pages | 9 |
Journal | Applied Catalysis A: General |
Volume | 388 |
Issue number | 1-2 |
DOIs | |
State | Published - Nov 20 2010 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors gratefully acknowledge the Région Rhône-Alpes Programme CIBLE-2007 (Contract number 07 016376 01/02/03) and the National Agency of Research (No. ANR-07-BLAN-0167-01/02) for funding. NB thanks Région Rhône-Alpes for a grant. AB thanks ANR for felowship. The authors kindly acknowledge the “Technical Center” of IRCELYON for analyses and helpful discussions (M. Aouine and L. Burel for TEM, P. Mascunan and N. Cristin for AAS analyses, P. Delichère and S. Prakash for XPS, F. Bosselet and G. Bergeret for XRD and C. Lorentz for solid-state NMR).
Keywords
- Heterogenous catalysis
- Indoles
- Larock synthesis
- Palladium catalysts
- SBA-15
ASJC Scopus subject areas
- Catalysis
- Process Chemistry and Technology