Asymmetric epoxidation of alkenes by a chiral manganese(III) salen complex anchored onto a functionalised hexagonal mesoporous silica

A R  Silva; Karen Wilson; J H  Clark; C  Freire

Asymmetric epoxidation of alkenes by a chiral manganese(III) salen complex anchored onto a functionalised hexagonal mesoporous silica

A R Silva, Karen Wilson, J H Clark, C Freire

Chemistry

Research output: Chapter in Book/Report/Conference proceeding › Chapter

Abstract

A Jacobsen-type catalyst was anchored onto an amine functionalised hexagonal mesoporous silica (HMS) through the diimine bridge fragment of the complex. The new heterogeneous catalyst, as well as the precedent materials, were characterised by elemental analyses, FTIR-DRIFT, UV-vis, porosimetry and XPS which showed that the complex was successfully anchored. This material was active in the epoxidation of styrene and alpha-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCI. With the former substrate no asymmetric induction was found in the epoxide, whereas with the latter substrate higher %ee was found than in homogeneous phase. Using the latter experimental conditions, catalyst reuse led to no significant loss of catalytic activity and enantioselectivity.

Original language	English
Title of host publication	Molecular Sieves: From Basic Research to Industrial Applications
Publisher	Elsevier
Pages	1525-1532
Number of pages	8
ISBN (Print)	978-0-444-52083-8
Publication status	Published - 2005

Publication series

Name	Studies in Surface Science and Catalysis
Publisher	Elsevier
Number	2
Volume	158

Keywords

(SALEN)MANGANESE(III) COMPLEXES
ENANTIOSELECTIVE EPOXIDATION
CATALYSIS
STYRENE

Cite this

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title = "Asymmetric epoxidation of alkenes by a chiral manganese(III) salen complex anchored onto a functionalised hexagonal mesoporous silica",

abstract = "A Jacobsen-type catalyst was anchored onto an amine functionalised hexagonal mesoporous silica (HMS) through the diimine bridge fragment of the complex. The new heterogeneous catalyst, as well as the precedent materials, were characterised by elemental analyses, FTIR-DRIFT, UV-vis, porosimetry and XPS which showed that the complex was successfully anchored. This material was active in the epoxidation of styrene and alpha-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCI. With the former substrate no asymmetric induction was found in the epoxide, whereas with the latter substrate higher %ee was found than in homogeneous phase. Using the latter experimental conditions, catalyst reuse led to no significant loss of catalytic activity and enantioselectivity.",

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author = "Silva, {A R} and Karen Wilson and Clark, {J H} and C Freire",

year = "2005",

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publisher = "Elsevier",

number = "2",

pages = "1525--1532",

booktitle = "Molecular Sieves: From Basic Research to Industrial Applications",

address = "Netherlands",

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Asymmetric epoxidation of alkenes by a chiral manganese(III) salen complex anchored onto a functionalised hexagonal mesoporous silica. / Silva, A R ; Wilson, Karen; Clark, J H et al.
Molecular Sieves: From Basic Research to Industrial Applications. Elsevier, 2005. p. 1525-1532 (Studies in Surface Science and Catalysis; Vol. 158, No. 2).

Research output: Chapter in Book/Report/Conference proceeding › Chapter

TY - CHAP

T1 - Asymmetric epoxidation of alkenes by a chiral manganese(III) salen complex anchored onto a functionalised hexagonal mesoporous silica

AU - Silva, A R

AU - Wilson, Karen

AU - Clark, J H

AU - Freire, C

PY - 2005

Y1 - 2005

N2 - A Jacobsen-type catalyst was anchored onto an amine functionalised hexagonal mesoporous silica (HMS) through the diimine bridge fragment of the complex. The new heterogeneous catalyst, as well as the precedent materials, were characterised by elemental analyses, FTIR-DRIFT, UV-vis, porosimetry and XPS which showed that the complex was successfully anchored. This material was active in the epoxidation of styrene and alpha-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCI. With the former substrate no asymmetric induction was found in the epoxide, whereas with the latter substrate higher %ee was found than in homogeneous phase. Using the latter experimental conditions, catalyst reuse led to no significant loss of catalytic activity and enantioselectivity.

AB - A Jacobsen-type catalyst was anchored onto an amine functionalised hexagonal mesoporous silica (HMS) through the diimine bridge fragment of the complex. The new heterogeneous catalyst, as well as the precedent materials, were characterised by elemental analyses, FTIR-DRIFT, UV-vis, porosimetry and XPS which showed that the complex was successfully anchored. This material was active in the epoxidation of styrene and alpha-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCI. With the former substrate no asymmetric induction was found in the epoxide, whereas with the latter substrate higher %ee was found than in homogeneous phase. Using the latter experimental conditions, catalyst reuse led to no significant loss of catalytic activity and enantioselectivity.

KW - (SALEN)MANGANESE(III) COMPLEXES

KW - ENANTIOSELECTIVE EPOXIDATION

KW - CATALYSIS

KW - STYRENE

M3 - Chapter

SN - 978-0-444-52083-8

T3 - Studies in Surface Science and Catalysis

SP - 1525

EP - 1532

BT - Molecular Sieves: From Basic Research to Industrial Applications

PB - Elsevier

ER -