Abstract
Pincer-ligated iridium complexes have proven to be highly effective catalysts for the dehydrogenation and transfer-dehydrogenation of alkanes. Immobilization onto a solid support offers significant potential advantages in the application of such catalysts particularly with respect to catalyst separation and recycling. We describe three approaches toward such immobilization: (i) covalent attachment to a Merrifield resin, (ii) covalent bonding to silica via a pendant alkoxysilane group, and (iii) adsorption on γ-alumina (γ-Al2O3), through basic functional groups on the para-position of the pincer ligand. The simplest of these approaches, adsorption on γ-Al2O3, is also found to be the most effective, yielding catalysts that are robust, recyclable, and comparable to or even more active than the corresponding species in solution. Spectroscopic evidence (NMR, IR) and studies of catalytic activity support the hypothesis that binding occurs at the para-substituent and that this has only a relatively subtle and indirect influence on catalytic behavior.
| Original language | English |
|---|---|
| Pages (from-to) | 188-206 |
| Number of pages | 19 |
| Journal | Advanced Synthesis and Catalysis |
| Volume | 351 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - Jan 2009 |
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Keywords
- Alkanes
- Alumina
- Dehydrogenation
- Iridium
- Pincer ligands
- Supported catalysts
ASJC Scopus subject areas
- Catalysis
- Organic Chemistry
Cite this
Highly active and recyclable heterogeneous iridium pincer catalysts for transfer dehydrogenation of alkanes. / Huang, Zheng; Brookhart, Maurice; Goldman, Alan S; Kundu, Sabuj; Ray, Amlan; Scott, Susannah L.; Vicente, Brian C.
In: Advanced Synthesis and Catalysis, Vol. 351, No. 1-2, 01.2009, p. 188-206.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Highly active and recyclable heterogeneous iridium pincer catalysts for transfer dehydrogenation of alkanes
AU - Huang, Zheng
AU - Brookhart, Maurice
AU - Goldman, Alan S
AU - Kundu, Sabuj
AU - Ray, Amlan
AU - Scott, Susannah L.
AU - Vicente, Brian C.
PY - 2009/1
Y1 - 2009/1
N2 - Pincer-ligated iridium complexes have proven to be highly effective catalysts for the dehydrogenation and transfer-dehydrogenation of alkanes. Immobilization onto a solid support offers significant potential advantages in the application of such catalysts particularly with respect to catalyst separation and recycling. We describe three approaches toward such immobilization: (i) covalent attachment to a Merrifield resin, (ii) covalent bonding to silica via a pendant alkoxysilane group, and (iii) adsorption on γ-alumina (γ-Al2O3), through basic functional groups on the para-position of the pincer ligand. The simplest of these approaches, adsorption on γ-Al2O3, is also found to be the most effective, yielding catalysts that are robust, recyclable, and comparable to or even more active than the corresponding species in solution. Spectroscopic evidence (NMR, IR) and studies of catalytic activity support the hypothesis that binding occurs at the para-substituent and that this has only a relatively subtle and indirect influence on catalytic behavior.
AB - Pincer-ligated iridium complexes have proven to be highly effective catalysts for the dehydrogenation and transfer-dehydrogenation of alkanes. Immobilization onto a solid support offers significant potential advantages in the application of such catalysts particularly with respect to catalyst separation and recycling. We describe three approaches toward such immobilization: (i) covalent attachment to a Merrifield resin, (ii) covalent bonding to silica via a pendant alkoxysilane group, and (iii) adsorption on γ-alumina (γ-Al2O3), through basic functional groups on the para-position of the pincer ligand. The simplest of these approaches, adsorption on γ-Al2O3, is also found to be the most effective, yielding catalysts that are robust, recyclable, and comparable to or even more active than the corresponding species in solution. Spectroscopic evidence (NMR, IR) and studies of catalytic activity support the hypothesis that binding occurs at the para-substituent and that this has only a relatively subtle and indirect influence on catalytic behavior.
KW - Alkanes
KW - Alumina
KW - Dehydrogenation
KW - Iridium
KW - Pincer ligands
KW - Supported catalysts
UR - http://www.scopus.com/inward/record.url?scp=58549092048&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=58549092048&partnerID=8YFLogxK
U2 - 10.1002/adsc.200800615
DO - 10.1002/adsc.200800615
M3 - Article
AN - SCOPUS:58549092048
VL - 351
SP - 188
EP - 206
JO - Journal fur Praktische Chemie
JF - Journal fur Praktische Chemie
SN - 1436-9966
IS - 1-2
ER -