Abstract
Both the bisphosphine and bisphosphinite pincer complexes ( tBu4PCP)IrH2 and (tBu4POCOP)IrH2 can cocatalyze alkane metathesis in tandem with olefin metathesis catalysts, but the two complexes have different resting states during catalysis, suggesting that different steps are turnover-limiting in each case. This led to the hypothesis that a complex with intermediate properties would be catalytically more active than either of these two species. Accordingly, "hybrid" phosphine-phosphinite pincer ligands (PCOP) and the corresponding iridium complexes were synthesized (3c-e). In tandem with olefin-metathesis catalyst MoF12, (tBu4PCOP)IrH2 displays significantly higher activity for the metathesis of n-hexane than does (tBu4PCP)IrH 2 or (tBu4POCOP)IrH2. (tBu2PCOP iPr2)IrH4 (3d) is even more active (>30-fold more active than (tBu4POCOP)IrH2) and affords nearly 4.6 M alkane products after 8 h at 125 C.
| Original language | English |
|---|---|
| Pages (from-to) | 2505-2514 |
| Number of pages | 10 |
| Journal | ACS Catalysis |
| Volume | 3 |
| Issue number | 11 |
| DOIs | |
| Publication status | Published - Nov 1 2013 |
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Keywords
- alkane metathesis
- dehydrogenation
- homogeneous catalysis
- iridium
- pincer complexes
ASJC Scopus subject areas
- Catalysis
Cite this
Rational design of highly active "hybrid" phosphine-phosphinite pincer iridium catalysts for alkane metathesis. / Nawara-Hultzsch, Agnieszka J.; Hackenberg, Jason D.; Punji, Benudhar; Supplee, Carolyn; Emge, Thomas J.; Bailey, Brad C.; Schrock, Richard R.; Brookhart, Maurice; Goldman, Alan S.
In: ACS Catalysis, Vol. 3, No. 11, 01.11.2013, p. 2505-2514.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Rational design of highly active "hybrid" phosphine-phosphinite pincer iridium catalysts for alkane metathesis
AU - Nawara-Hultzsch, Agnieszka J.
AU - Hackenberg, Jason D.
AU - Punji, Benudhar
AU - Supplee, Carolyn
AU - Emge, Thomas J.
AU - Bailey, Brad C.
AU - Schrock, Richard R.
AU - Brookhart, Maurice
AU - Goldman, Alan S
PY - 2013/11/1
Y1 - 2013/11/1
N2 - Both the bisphosphine and bisphosphinite pincer complexes ( tBu4PCP)IrH2 and (tBu4POCOP)IrH2 can cocatalyze alkane metathesis in tandem with olefin metathesis catalysts, but the two complexes have different resting states during catalysis, suggesting that different steps are turnover-limiting in each case. This led to the hypothesis that a complex with intermediate properties would be catalytically more active than either of these two species. Accordingly, "hybrid" phosphine-phosphinite pincer ligands (PCOP) and the corresponding iridium complexes were synthesized (3c-e). In tandem with olefin-metathesis catalyst MoF12, (tBu4PCOP)IrH2 displays significantly higher activity for the metathesis of n-hexane than does (tBu4PCP)IrH 2 or (tBu4POCOP)IrH2. (tBu2PCOP iPr2)IrH4 (3d) is even more active (>30-fold more active than (tBu4POCOP)IrH2) and affords nearly 4.6 M alkane products after 8 h at 125 C.
AB - Both the bisphosphine and bisphosphinite pincer complexes ( tBu4PCP)IrH2 and (tBu4POCOP)IrH2 can cocatalyze alkane metathesis in tandem with olefin metathesis catalysts, but the two complexes have different resting states during catalysis, suggesting that different steps are turnover-limiting in each case. This led to the hypothesis that a complex with intermediate properties would be catalytically more active than either of these two species. Accordingly, "hybrid" phosphine-phosphinite pincer ligands (PCOP) and the corresponding iridium complexes were synthesized (3c-e). In tandem with olefin-metathesis catalyst MoF12, (tBu4PCOP)IrH2 displays significantly higher activity for the metathesis of n-hexane than does (tBu4PCP)IrH 2 or (tBu4POCOP)IrH2. (tBu2PCOP iPr2)IrH4 (3d) is even more active (>30-fold more active than (tBu4POCOP)IrH2) and affords nearly 4.6 M alkane products after 8 h at 125 C.
KW - alkane metathesis
KW - dehydrogenation
KW - homogeneous catalysis
KW - iridium
KW - pincer complexes
UR - http://www.scopus.com/inward/record.url?scp=84887377533&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84887377533&partnerID=8YFLogxK
U2 - 10.1021/cs400624c
DO - 10.1021/cs400624c
M3 - Article
AN - SCOPUS:84887377533
VL - 3
SP - 2505
EP - 2514
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 11
ER -