New ionic liquid-modified silica gels as recyclable materials for L-proline- or H-Pro-Pro-Asp-NH2-catalyzed aldol reaction

Francesco Giacalone, Michelangelo Gruttadauria, Adriana Mossuto Marculescu, Renato Noto, Helma Wennemers, Jefferson D. Revell, Carmela Aprile

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68 Citations (Scopus)

Abstract

L-proline and the tripeptide H–Pro–Pro–Asp–NH2 (1) have been supported, by adsorption, onto the surface of modified silica gels functionalized with a monolayer of covalently attached 1,2-dimethyl-imidazolium chloride, tetrafluoroborate or hexafluorophosphate ionic moieties, respectively. Three different linkers were used to attach the ionic liquid moiety to the surface of these supports. The resulting materials have been used as catalysts for the aldol reaction between acetone and several substituted benzaldehydes. Good yields and enantioselectivities, comparable to or better than those obtained under homogeneous conditions, were obtained. These materials are easily recovered by filtration, and studies regarding their re-use have been carried out. Studies performed using L-proline-supported materials have shown that the re-use of these materials is dependent on the nature of the linker. The supported tripeptide H–Pro–Pro–Asp–NH2 gave higher enantioselectivities than those obtained with supported-proline. Recycling investigations using tripeptide-supported materials showed continued good selectivities but diminishing conversions over consecutive runs. L-proline-supported materials however, can be used at least nine times without loss of either conversion or selectivity.
Original languageEnglish
Pages (from-to)1328-1334
Number of pages7
JournalGreen Chemistry
Volume9
Publication statusPublished - 2007

Fingerprint

Ionic Liquids
Silica Gel
Silica gel
Ionic liquids
Proline
gel
silica
Enantioselectivity
Benzaldehydes
acetone
Acetone
recycling
catalyst
chloride
H-Pro-Pro-Asp-NH2
3-hydroxybutanal
ionic liquid
material
Recycling
Monolayers

All Science Journal Classification (ASJC) codes

  • Environmental Chemistry
  • Pollution

Cite this

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title = "New ionic liquid-modified silica gels as recyclable materials for L-proline- or H-Pro-Pro-Asp-NH2-catalyzed aldol reaction",
abstract = "L-proline and the tripeptide H–Pro–Pro–Asp–NH2 (1) have been supported, by adsorption, onto the surface of modified silica gels functionalized with a monolayer of covalently attached 1,2-dimethyl-imidazolium chloride, tetrafluoroborate or hexafluorophosphate ionic moieties, respectively. Three different linkers were used to attach the ionic liquid moiety to the surface of these supports. The resulting materials have been used as catalysts for the aldol reaction between acetone and several substituted benzaldehydes. Good yields and enantioselectivities, comparable to or better than those obtained under homogeneous conditions, were obtained. These materials are easily recovered by filtration, and studies regarding their re-use have been carried out. Studies performed using L-proline-supported materials have shown that the re-use of these materials is dependent on the nature of the linker. The supported tripeptide H–Pro–Pro–Asp–NH2 gave higher enantioselectivities than those obtained with supported-proline. Recycling investigations using tripeptide-supported materials showed continued good selectivities but diminishing conversions over consecutive runs. L-proline-supported materials however, can be used at least nine times without loss of either conversion or selectivity.",
keywords = "Organocatalysis, Proline",
author = "Francesco Giacalone and Michelangelo Gruttadauria and {Mossuto Marculescu}, Adriana and Renato Noto and Helma Wennemers and Revell, {Jefferson D.} and Carmela Aprile",
year = "2007",
language = "English",
volume = "9",
pages = "1328--1334",
journal = "Green Chemistry",
issn = "1463-9262",
publisher = "Royal Society of Chemistry",

}

TY - JOUR

T1 - New ionic liquid-modified silica gels as recyclable materials for L-proline- or H-Pro-Pro-Asp-NH2-catalyzed aldol reaction

AU - Giacalone, Francesco

AU - Gruttadauria, Michelangelo

AU - Mossuto Marculescu, Adriana

AU - Noto, Renato

AU - Wennemers, Helma

AU - Revell, Jefferson D.

AU - Aprile, Carmela

PY - 2007

Y1 - 2007

N2 - L-proline and the tripeptide H–Pro–Pro–Asp–NH2 (1) have been supported, by adsorption, onto the surface of modified silica gels functionalized with a monolayer of covalently attached 1,2-dimethyl-imidazolium chloride, tetrafluoroborate or hexafluorophosphate ionic moieties, respectively. Three different linkers were used to attach the ionic liquid moiety to the surface of these supports. The resulting materials have been used as catalysts for the aldol reaction between acetone and several substituted benzaldehydes. Good yields and enantioselectivities, comparable to or better than those obtained under homogeneous conditions, were obtained. These materials are easily recovered by filtration, and studies regarding their re-use have been carried out. Studies performed using L-proline-supported materials have shown that the re-use of these materials is dependent on the nature of the linker. The supported tripeptide H–Pro–Pro–Asp–NH2 gave higher enantioselectivities than those obtained with supported-proline. Recycling investigations using tripeptide-supported materials showed continued good selectivities but diminishing conversions over consecutive runs. L-proline-supported materials however, can be used at least nine times without loss of either conversion or selectivity.

AB - L-proline and the tripeptide H–Pro–Pro–Asp–NH2 (1) have been supported, by adsorption, onto the surface of modified silica gels functionalized with a monolayer of covalently attached 1,2-dimethyl-imidazolium chloride, tetrafluoroborate or hexafluorophosphate ionic moieties, respectively. Three different linkers were used to attach the ionic liquid moiety to the surface of these supports. The resulting materials have been used as catalysts for the aldol reaction between acetone and several substituted benzaldehydes. Good yields and enantioselectivities, comparable to or better than those obtained under homogeneous conditions, were obtained. These materials are easily recovered by filtration, and studies regarding their re-use have been carried out. Studies performed using L-proline-supported materials have shown that the re-use of these materials is dependent on the nature of the linker. The supported tripeptide H–Pro–Pro–Asp–NH2 gave higher enantioselectivities than those obtained with supported-proline. Recycling investigations using tripeptide-supported materials showed continued good selectivities but diminishing conversions over consecutive runs. L-proline-supported materials however, can be used at least nine times without loss of either conversion or selectivity.

KW - Organocatalysis

KW - Proline

UR - http://hdl.handle.net/10447/27504

M3 - Article

VL - 9

SP - 1328

EP - 1334

JO - Green Chemistry

JF - Green Chemistry

SN - 1463-9262

ER -