Unusual deactivation in the asymmetric hydrogenation of itaconic acid
Research output: Journal contributions › Journal articles › Research › peer-review
Standard
In: Journal of Organometallic Chemistry, Vol. 696, No. 9, 01.05.2011, p. 1760-1767.
Research output: Journal contributions › Journal articles › Research › peer-review
Harvard
APA
Vancouver
Bibtex
}
RIS
TY - JOUR
T1 - Unusual deactivation in the asymmetric hydrogenation of itaconic acid
AU - Schmidt, Thomas
AU - Baumann, Wolfgang
AU - Drexler, Hans‐Joachim
AU - Heller, Detlef
PY - 2011/5/1
Y1 - 2011/5/1
N2 - The formation of unusual Rh(III) substrate complexes from [Rh(DIPAMP)(MeOH)2]BF4 and itaconic acid has been detected which leads to the deactivation of the catalyst. The influence of different parameters on the formation of such complexes, namely substrate concentration, reaction time, temperature, acidic and basic additives, was investigated with different NMR methods. Two different Rh(III) substrate complexes are formed whose ratio is strongly dependent on substrate concentration and reaction time. The pH value of the solution shows a strong influence on the chemical shifts of the 31P NMR signals of such complexes. A catalyst-mediated esterification of itaconic acid in methanol was detected. Extended investigations provide detailed 1H, 13C and 31P NMR data for the Rh(III) complexes and information about their stability in solution.
AB - The formation of unusual Rh(III) substrate complexes from [Rh(DIPAMP)(MeOH)2]BF4 and itaconic acid has been detected which leads to the deactivation of the catalyst. The influence of different parameters on the formation of such complexes, namely substrate concentration, reaction time, temperature, acidic and basic additives, was investigated with different NMR methods. Two different Rh(III) substrate complexes are formed whose ratio is strongly dependent on substrate concentration and reaction time. The pH value of the solution shows a strong influence on the chemical shifts of the 31P NMR signals of such complexes. A catalyst-mediated esterification of itaconic acid in methanol was detected. Extended investigations provide detailed 1H, 13C and 31P NMR data for the Rh(III) complexes and information about their stability in solution.
KW - Chemistry
KW - Homogeneous catalysis
KW - Enantioselective hydrogenation
KW - Itaconic acid
KW - Catalyst deactivation
KW - Rhodium alkyl complex
UR - http://www.scopus.com/inward/record.url?scp=79954993724&partnerID=8YFLogxK
U2 - 10.1016/j.jorganchem.2010.12.020
DO - 10.1016/j.jorganchem.2010.12.020
M3 - Journal articles
VL - 696
SP - 1760
EP - 1767
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
SN - 0022-328X
IS - 9
ER -