Abstract
Ruthenium complexes with the formulae Ru(CO)(2)(PR3)(2)(O2CPh)(2) [6a-h; R=n-Bu, p-MeO-C6H4, p-Me-C6H4, Ph, p-Cl-C6H4, m-Cl-C6H4, p-CF3-C6H4, m,m'-(CF3)(2)C6H3] were prepared by treatment of triruthenium dodecacarbonyl [Ru-3(CO)(12)] with the respective phosphine and benzoic acid or by the conversion of Ru(CO)(3)(PR3)(2) (8e-h) with benzoic acid. During the preparation of 8, ruthenium hydride complexes of type Ru(CO)(PR3)(3)(H)(2) (9g, h) could be isolated as side products. The molecular structures of the newly synthesized complexes in the solid state are discussed. Compounds 6a-h were found to be highly effective catalysts in the addition of carboxylic acids to propargylic alcohols to give valuable beta-oxo esters. The catalyst screening revealed a considerably influence of the phosphine's electronic nature on the resulting activities. The best performances were obtained with complexes 6g and 6h, featuring electron-withdrawing phosphine ligands. Additionally, catalyst 6g is very active in the conversion of sterically demanding substrates, leading to a broad substrate scope. The catalytic preparation of simple as well as challenging substrates succeeds with catalyst 6g in yields that often exceed those of established literature systems. Furthermore, the reactions can be carried out with catalyst loadings down to 0.1 mol% and reaction temperatures down to 50 degrees C.
| Original language | English |
|---|---|
| Pages (from-to) | 4069-4081 |
| Number of pages | 13 |
| Journal | ADVANCED SYNTHESIS & CATALYSIS |
| Volume | 357 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - 14 Dec 2015 |
| Externally published | Yes |
Cite this
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Atom Economic Ruthenium-Catalyzed Synthesis of Bulky beta-Oxo Esters. / Jeschke, Janine; Korb, Marcus; Rueffer, Tobias; Gaebler, Christian; Lang, Heinrich.
In: ADVANCED SYNTHESIS & CATALYSIS, Vol. 357, No. 18, 14.12.2015, p. 4069-4081.Research output: Contribution to journal › Article
TY - JOUR
T1 - Atom Economic Ruthenium-Catalyzed Synthesis of Bulky beta-Oxo Esters
AU - Jeschke, Janine
AU - Korb, Marcus
AU - Rueffer, Tobias
AU - Gaebler, Christian
AU - Lang, Heinrich
PY - 2015/12/14
Y1 - 2015/12/14
N2 - Ruthenium complexes with the formulae Ru(CO)(2)(PR3)(2)(O2CPh)(2) [6a-h; R=n-Bu, p-MeO-C6H4, p-Me-C6H4, Ph, p-Cl-C6H4, m-Cl-C6H4, p-CF3-C6H4, m,m'-(CF3)(2)C6H3] were prepared by treatment of triruthenium dodecacarbonyl [Ru-3(CO)(12)] with the respective phosphine and benzoic acid or by the conversion of Ru(CO)(3)(PR3)(2) (8e-h) with benzoic acid. During the preparation of 8, ruthenium hydride complexes of type Ru(CO)(PR3)(3)(H)(2) (9g, h) could be isolated as side products. The molecular structures of the newly synthesized complexes in the solid state are discussed. Compounds 6a-h were found to be highly effective catalysts in the addition of carboxylic acids to propargylic alcohols to give valuable beta-oxo esters. The catalyst screening revealed a considerably influence of the phosphine's electronic nature on the resulting activities. The best performances were obtained with complexes 6g and 6h, featuring electron-withdrawing phosphine ligands. Additionally, catalyst 6g is very active in the conversion of sterically demanding substrates, leading to a broad substrate scope. The catalytic preparation of simple as well as challenging substrates succeeds with catalyst 6g in yields that often exceed those of established literature systems. Furthermore, the reactions can be carried out with catalyst loadings down to 0.1 mol% and reaction temperatures down to 50 degrees C.
AB - Ruthenium complexes with the formulae Ru(CO)(2)(PR3)(2)(O2CPh)(2) [6a-h; R=n-Bu, p-MeO-C6H4, p-Me-C6H4, Ph, p-Cl-C6H4, m-Cl-C6H4, p-CF3-C6H4, m,m'-(CF3)(2)C6H3] were prepared by treatment of triruthenium dodecacarbonyl [Ru-3(CO)(12)] with the respective phosphine and benzoic acid or by the conversion of Ru(CO)(3)(PR3)(2) (8e-h) with benzoic acid. During the preparation of 8, ruthenium hydride complexes of type Ru(CO)(PR3)(3)(H)(2) (9g, h) could be isolated as side products. The molecular structures of the newly synthesized complexes in the solid state are discussed. Compounds 6a-h were found to be highly effective catalysts in the addition of carboxylic acids to propargylic alcohols to give valuable beta-oxo esters. The catalyst screening revealed a considerably influence of the phosphine's electronic nature on the resulting activities. The best performances were obtained with complexes 6g and 6h, featuring electron-withdrawing phosphine ligands. Additionally, catalyst 6g is very active in the conversion of sterically demanding substrates, leading to a broad substrate scope. The catalytic preparation of simple as well as challenging substrates succeeds with catalyst 6g in yields that often exceed those of established literature systems. Furthermore, the reactions can be carried out with catalyst loadings down to 0.1 mol% and reaction temperatures down to 50 degrees C.
KW - homogeneous catalysis
KW - phosphines
KW - propargylic alcohols
KW - ruthenium
KW - solid state structure
KW - METAL VINYLIDENE COMPLEXES
KW - C BOND FORMATION
KW - CARBOXYLIC-ACIDS
KW - TERMINAL ALKYNES
KW - ENOL ESTERS
KW - STEREOSELECTIVE ADDITION
KW - PROPARGYLIC ALCOHOLS
KW - EFFICIENT SYNTHESIS
KW - FACILE SYNTHESIS
KW - PLATINUM METALS
U2 - 10.1002/adsc.201500712
DO - 10.1002/adsc.201500712
M3 - Article
VL - 357
SP - 4069
EP - 4081
JO - ADVANCED SYNTHESIS & CATALYSIS
JF - ADVANCED SYNTHESIS & CATALYSIS
SN - 1615-4150
IS - 18
ER -