Enantioselective epoxidation of chalcone catalysed by the artificial enzyme poly-L-leucine: Kinetic mechanism

Tetrahedron Asymmetry

Volumn 15, Issue 18, 2004, Pages 2945-2949

  Carrea, Giacomo ^a   Colonna, Stefano ^b   Meek, Alastair D ^c   Ottolina, Gianluca ^a   Roberts, Stanley M ^c  

^a CNR   (Italy)

^b Via Venezian 21 20133 Milano Italy   (Italy)

^c UNIVERSITY OF LIVERPOOL   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

CHALCONE; ENZYME; HYDROGEN PEROXIDE; LEUCINE;

ARTICLE; CATALYSIS; CATALYST; CHEMICAL BINDING; COMPLEX FORMATION; ENANTIOSELECTIVITY; EPOXIDATION; KINETICS; PRIORITY JOURNAL;

EID: 4644328196     PISSN: 09574166     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetasy.2004.06.046     Document Type: Article

References (26)

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18. The catalyst solution in THF was slightly turbid and was clarified by centrifugation. The pellet, which represented 1.7% of the total catalyst, was unable to catalyse the epoxidation of chalcone
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21. It was not possible to use chalcone concentrations substantially higher than 120 mM because of the too high substrate absorption and increase of spontaneous oxidation. However, extrapolation of the theoretical curves of Figure 3 at higher chalcone concentration, clearly indicated marked substrate inhibition
22. 14 and the high BEMP/PLL ratio (≥50, on a molar basis) should always assure complete deprotonation of the catalyst
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26. For example, in the case of Figure 3, the symbols of Eq. 1 have the following meaning: v is the initial rate in the presence of a fixed concentration of hydrogen peroxide, a is the concentration of chalcone, and i, j, k, l and m are functions of hydrogen peroxide concentration and of the rate constants for the various steps of Scheme 2. For additional details see: E.L. King J. Phys. Chem. 60 1956 1378 1381