Abstract
The functional group tolerance and substrate scope for bis(imino)pyridine iron catalyzed olefin hydrogenation have been examined. Allyl amines, R 2NCH2CH=CH2 (R = H, Me), are hydrogenated in the presence of (iPrPDI)Fe(N2)2 ( iPrPDI = 2,6-(2,6-iPr2-C6H 3N=CMe)2C5H3N, 1-(N 2)2) and the observed turnover frequencies increase with steric protection of the nitrogen donor. Likewise, ether-substituted olefins such as ethyl vinyl ether, ethyl allyl ether, and allyl ether are hydrogenated with turnover frequencies indistinguishable from the analogous α-olefins. For carbonyl-substituted alkenes, the hydrogenation activity is exquisitely sensitive to the position and type of the functional group. Esters such as dimethyl itaconate and iraas-methyl cinnamate are effectively hydrogenated at 23 °C while ketones such as 5-hexen-2-one require heating to 65 °C for efficient turnover. In contrast, conjugated α,β-unsaturated ketones induce decomposition of the iron compound. Stoichiometric experiments were conducted to probe the iron substrate interaction and to gauge the coordination affinity of the functional group relative to the alkene. In addition, several new bis(irnino)pyridine iron amine and ketone complexes were synthesized and the molecular and electronic structures probed by NMR spectroscopy, Mössbauer spectroscopy, and in one case, X-ray diffraction.
| Original language | English |
|---|---|
| Pages (from-to) | 1470-1478 |
| Number of pages | 9 |
| Journal | Organometallics |
| Volume | 27 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - Apr 14 2008 |
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ASJC Scopus subject areas
- Inorganic Chemistry
- Organic Chemistry
Cite this
Functional group tolerance and substrate scope in bis(imino)pyridine iron catalyzed alkene hydrogenation. / Trovitch, Ryan; Lobkovsky, Emil; Bill, Eckhard; Chirik, Paul J.
In: Organometallics, Vol. 27, No. 7, 14.04.2008, p. 1470-1478.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Functional group tolerance and substrate scope in bis(imino)pyridine iron catalyzed alkene hydrogenation
AU - Trovitch, Ryan
AU - Lobkovsky, Emil
AU - Bill, Eckhard
AU - Chirik, Paul J.
PY - 2008/4/14
Y1 - 2008/4/14
N2 - The functional group tolerance and substrate scope for bis(imino)pyridine iron catalyzed olefin hydrogenation have been examined. Allyl amines, R 2NCH2CH=CH2 (R = H, Me), are hydrogenated in the presence of (iPrPDI)Fe(N2)2 ( iPrPDI = 2,6-(2,6-iPr2-C6H 3N=CMe)2C5H3N, 1-(N 2)2) and the observed turnover frequencies increase with steric protection of the nitrogen donor. Likewise, ether-substituted olefins such as ethyl vinyl ether, ethyl allyl ether, and allyl ether are hydrogenated with turnover frequencies indistinguishable from the analogous α-olefins. For carbonyl-substituted alkenes, the hydrogenation activity is exquisitely sensitive to the position and type of the functional group. Esters such as dimethyl itaconate and iraas-methyl cinnamate are effectively hydrogenated at 23 °C while ketones such as 5-hexen-2-one require heating to 65 °C for efficient turnover. In contrast, conjugated α,β-unsaturated ketones induce decomposition of the iron compound. Stoichiometric experiments were conducted to probe the iron substrate interaction and to gauge the coordination affinity of the functional group relative to the alkene. In addition, several new bis(irnino)pyridine iron amine and ketone complexes were synthesized and the molecular and electronic structures probed by NMR spectroscopy, Mössbauer spectroscopy, and in one case, X-ray diffraction.
AB - The functional group tolerance and substrate scope for bis(imino)pyridine iron catalyzed olefin hydrogenation have been examined. Allyl amines, R 2NCH2CH=CH2 (R = H, Me), are hydrogenated in the presence of (iPrPDI)Fe(N2)2 ( iPrPDI = 2,6-(2,6-iPr2-C6H 3N=CMe)2C5H3N, 1-(N 2)2) and the observed turnover frequencies increase with steric protection of the nitrogen donor. Likewise, ether-substituted olefins such as ethyl vinyl ether, ethyl allyl ether, and allyl ether are hydrogenated with turnover frequencies indistinguishable from the analogous α-olefins. For carbonyl-substituted alkenes, the hydrogenation activity is exquisitely sensitive to the position and type of the functional group. Esters such as dimethyl itaconate and iraas-methyl cinnamate are effectively hydrogenated at 23 °C while ketones such as 5-hexen-2-one require heating to 65 °C for efficient turnover. In contrast, conjugated α,β-unsaturated ketones induce decomposition of the iron compound. Stoichiometric experiments were conducted to probe the iron substrate interaction and to gauge the coordination affinity of the functional group relative to the alkene. In addition, several new bis(irnino)pyridine iron amine and ketone complexes were synthesized and the molecular and electronic structures probed by NMR spectroscopy, Mössbauer spectroscopy, and in one case, X-ray diffraction.
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U2 - 10.1021/om701091z
DO - 10.1021/om701091z
M3 - Article
VL - 27
SP - 1470
EP - 1478
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 7
ER -