TY - JOUR
T1 - Effect of ultrasound in enantioselective hydrogenation of 1-phenyl-1,2-propanedione
T2 - comparison of catalyst activation, solvents and supports
AU - Toukoniitty, B.
AU - Toukoniitty, E.
AU - Mäki-Arvela, P.
AU - Mikkola, J.-P.
AU - Salmi, T.
AU - Murzin, D. Yu.
AU - Kooyman, P. J.
PY - 2006/1
Y1 - 2006/1
N2 - The enantioselective hydrogenation of 1-phenyl-1,2-propanedione was carried out over Pt/Al2O3, Pt/SiO2, Pt/SF (silica fiber), Pt/C catalysts modified with cinchonidine under ultrasonic irradiation. The initial rate, regioselectivity and enantioselectivity were investigated for different catalyst pretreatments, solvents and ultrasonic powers. The ultrasound effects were very catalyst dependent. The sonication significantly enhanced enantioselectivity and activity of the Pt/SF (silica fiber) catalyst. For the other Pt supported catalysts the reaction rate, enantioselectivity and regioselectivity increased moderately. The choice of solvent influenced the impact of ultrasound effect, namely in mesitylene, which has the lowest vapor pressure, the highest ultrasound enhancement was observed. The effect of sonication on catalysts surface was studied by transmission electron microscopy and scanning electron microscopy (SEM). No significant change in the metal particle size distribution due to sonication was observed. However, in the case of the Pt/SF catalyst, acoustic irradiation induced morphological changes on the catalyst particle surface (SEM), which might be the cause for enhancement of the initial reaction rate and enantioselectivity.
AB - The enantioselective hydrogenation of 1-phenyl-1,2-propanedione was carried out over Pt/Al2O3, Pt/SiO2, Pt/SF (silica fiber), Pt/C catalysts modified with cinchonidine under ultrasonic irradiation. The initial rate, regioselectivity and enantioselectivity were investigated for different catalyst pretreatments, solvents and ultrasonic powers. The ultrasound effects were very catalyst dependent. The sonication significantly enhanced enantioselectivity and activity of the Pt/SF (silica fiber) catalyst. For the other Pt supported catalysts the reaction rate, enantioselectivity and regioselectivity increased moderately. The choice of solvent influenced the impact of ultrasound effect, namely in mesitylene, which has the lowest vapor pressure, the highest ultrasound enhancement was observed. The effect of sonication on catalysts surface was studied by transmission electron microscopy and scanning electron microscopy (SEM). No significant change in the metal particle size distribution due to sonication was observed. However, in the case of the Pt/SF catalyst, acoustic irradiation induced morphological changes on the catalyst particle surface (SEM), which might be the cause for enhancement of the initial reaction rate and enantioselectivity.
KW - Catalysis
KW - Chalcones/chemistry
KW - Hydrogen/chemistry
KW - Hydrogenation
KW - Isomerism
KW - Lead/chemistry
KW - Solvents/chemistry
KW - Sonication
KW - Substrate Specificity
U2 - 10.1016/j.ultsonch.2004.11.001
DO - 10.1016/j.ultsonch.2004.11.001
M3 - Article
C2 - 16223690
SN - 1350-4177
VL - 13
SP - 68
EP - 75
JO - Ultrasonics Sonochemistry
JF - Ultrasonics Sonochemistry
IS - 1
ER -