Premodification of Pt/gamma Al2O3 with cinchonidine for the enantioselective hydrogenation of ethyl pyruvate

effect of premodification conditions on reaction rate and enantioselection

X B Li, R P K Wells, P B Wells, G J Hutchings

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1 Citation (Scopus)

Abstract

The premodification of a 5 wt% Pt=gamma-Al2O3 catalyst with cinchonidine (0.01 and 0.2 g g(catalyst)(-1)) is described and discussed. Premodification is carried out by treating the catalyst with a solution of cinchonidine followed by solvent removal. Catalysts premodified in this way give the same ee and initial rate of reaction for the enantioselective hydrogenation of ethyl pyruvate as those using the standard in situ modi. cation procedure. Investigations of different solvents for premodification and reaction ( dichloromethane, ethanol) show that it is the solvent used for the reaction that controls the observed enantioselection. Premodified catalysts also display the initial transient behavior typically observed with in situ modified catalysts in which the ee increases with conversion in the early part of the reaction. Premodified catalysts show an enhanced rate of reaction when ethanol is used as the reaction solvent compared with in situ modified catalysts under the same conditions. Premodification using aerobic conditions gives the best results and premodified catalysts can be stored prior to use for up to a week without loss of catalytic performance.

Original languageEnglish
Pages (from-to)163-167
Number of pages5
JournalCatalysis Letters
Volume89
Issue number3-4
Publication statusPublished - Sep 2003

Keywords

  • Pt/gamma Al2O3
  • premodification/cinchonidine
  • ethyl pyruvate hydrogenation
  • enantioselective hydrogenation
  • initial transient period
  • asymmetric heterogeneous aziridination
  • platinum silica Europt-1
  • nitrene donor
  • group metals
  • catalysts
  • zeolite
  • 10,11-dihydrocinchonidine
  • PD
  • selectivity

Cite this

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title = "Premodification of Pt/gamma Al2O3 with cinchonidine for the enantioselective hydrogenation of ethyl pyruvate: effect of premodification conditions on reaction rate and enantioselection",
abstract = "The premodification of a 5 wt{\%} Pt=gamma-Al2O3 catalyst with cinchonidine (0.01 and 0.2 g g(catalyst)(-1)) is described and discussed. Premodification is carried out by treating the catalyst with a solution of cinchonidine followed by solvent removal. Catalysts premodified in this way give the same ee and initial rate of reaction for the enantioselective hydrogenation of ethyl pyruvate as those using the standard in situ modi. cation procedure. Investigations of different solvents for premodification and reaction ( dichloromethane, ethanol) show that it is the solvent used for the reaction that controls the observed enantioselection. Premodified catalysts also display the initial transient behavior typically observed with in situ modified catalysts in which the ee increases with conversion in the early part of the reaction. Premodified catalysts show an enhanced rate of reaction when ethanol is used as the reaction solvent compared with in situ modified catalysts under the same conditions. Premodification using aerobic conditions gives the best results and premodified catalysts can be stored prior to use for up to a week without loss of catalytic performance.",
keywords = "Pt/gamma Al2O3, premodification/cinchonidine, ethyl pyruvate hydrogenation, enantioselective hydrogenation, initial transient period, asymmetric heterogeneous aziridination, platinum silica Europt-1, nitrene donor, group metals, catalysts, zeolite, 10,11-dihydrocinchonidine, PD, selectivity",
author = "Li, {X B} and Wells, {R P K} and Wells, {P B} and Hutchings, {G J}",
year = "2003",
month = "9",
language = "English",
volume = "89",
pages = "163--167",
journal = "Catalysis Letters",
issn = "1011-372X",
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TY - JOUR

T1 - Premodification of Pt/gamma Al2O3 with cinchonidine for the enantioselective hydrogenation of ethyl pyruvate

T2 - effect of premodification conditions on reaction rate and enantioselection

AU - Li, X B

AU - Wells, R P K

AU - Wells, P B

AU - Hutchings, G J

PY - 2003/9

Y1 - 2003/9

N2 - The premodification of a 5 wt% Pt=gamma-Al2O3 catalyst with cinchonidine (0.01 and 0.2 g g(catalyst)(-1)) is described and discussed. Premodification is carried out by treating the catalyst with a solution of cinchonidine followed by solvent removal. Catalysts premodified in this way give the same ee and initial rate of reaction for the enantioselective hydrogenation of ethyl pyruvate as those using the standard in situ modi. cation procedure. Investigations of different solvents for premodification and reaction ( dichloromethane, ethanol) show that it is the solvent used for the reaction that controls the observed enantioselection. Premodified catalysts also display the initial transient behavior typically observed with in situ modified catalysts in which the ee increases with conversion in the early part of the reaction. Premodified catalysts show an enhanced rate of reaction when ethanol is used as the reaction solvent compared with in situ modified catalysts under the same conditions. Premodification using aerobic conditions gives the best results and premodified catalysts can be stored prior to use for up to a week without loss of catalytic performance.

AB - The premodification of a 5 wt% Pt=gamma-Al2O3 catalyst with cinchonidine (0.01 and 0.2 g g(catalyst)(-1)) is described and discussed. Premodification is carried out by treating the catalyst with a solution of cinchonidine followed by solvent removal. Catalysts premodified in this way give the same ee and initial rate of reaction for the enantioselective hydrogenation of ethyl pyruvate as those using the standard in situ modi. cation procedure. Investigations of different solvents for premodification and reaction ( dichloromethane, ethanol) show that it is the solvent used for the reaction that controls the observed enantioselection. Premodified catalysts also display the initial transient behavior typically observed with in situ modified catalysts in which the ee increases with conversion in the early part of the reaction. Premodified catalysts show an enhanced rate of reaction when ethanol is used as the reaction solvent compared with in situ modified catalysts under the same conditions. Premodification using aerobic conditions gives the best results and premodified catalysts can be stored prior to use for up to a week without loss of catalytic performance.

KW - Pt/gamma Al2O3

KW - premodification/cinchonidine

KW - ethyl pyruvate hydrogenation

KW - enantioselective hydrogenation

KW - initial transient period

KW - asymmetric heterogeneous aziridination

KW - platinum silica Europt-1

KW - nitrene donor

KW - group metals

KW - catalysts

KW - zeolite

KW - 10,11-dihydrocinchonidine

KW - PD

KW - selectivity

M3 - Article

VL - 89

SP - 163

EP - 167

JO - Catalysis Letters

JF - Catalysis Letters

SN - 1011-372X

IS - 3-4

ER -