Chiral manganese(III) Schiff base complexes anchored onto activated carbon as enantio selective heterogeneous catalysts for alkene epoxidation

A R  Silva; V  Budarin; J H  Clark; B  de Castro; C  Freire

doi:10.1016/j.carbon.2005.03.024

Chiral manganese(III) Schiff base complexes anchored onto activated carbon as enantio selective heterogeneous catalysts for alkene epoxidation

A R Silva, V Budarin, J H Clark, B de Castro, C Freire

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Two chiral manganese(III) salen catalysts, bearing different chiral diamine bridges, were anchored by direct axial coordination of the metal centre onto the phenolate groups of a modified commercial activated carbon. The modification of the activated carbon was achieved by reaction between sodium hydroxide and surface phenol groups giving rise to phenolate groups (CoxONa), which were characterised by XPS, TG and TG-IR. Characterisation of immobilised manganese(III) salen catalysts onto CoxONa material by XPS, ICP-AES and TG-IR clearly point to reaction between carbon surface phenolate groups and the manganese(III) complexes through axial coordination of the metal centre to these groups.

These materials were active and enantioselective in the epoxidation of styrene and a-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCl. Only for alpha-methylstyrene comparable asymmetric inductions were found in the epoxide as the homogeneous phase reactions and catalyst reuse led to no significant loss of catalytic activity and enantioselectivity. (C) 2005 Elsevier Ltd. All rights reserved.

Original language	English
Pages (from-to)	2096-2105
Number of pages	10
Journal	CARBON
Volume	43
Issue number	10
DOIs	https://doi.org/10.1016/j.carbon.2005.03.024
Publication status	Published - Aug 2005

Keywords

activated carbon
chemically modified carbons
catalyst
catalyst support
catalytic properties
SALEN COMPLEXES
ENANTIOSELECTIVE EPOXIDATION
OLEFINS
IMMOBILIZATION
MODULATION
CHLORIDE
STYRENE

Access to Document

10.1016/j.carbon.2005.03.024

Cite this

@article{619e44541f374b1baae87ae858a6aafb,

title = "Chiral manganese(III) Schiff base complexes anchored onto activated carbon as enantio selective heterogeneous catalysts for alkene epoxidation",

abstract = "Two chiral manganese(III) salen catalysts, bearing different chiral diamine bridges, were anchored by direct axial coordination of the metal centre onto the phenolate groups of a modified commercial activated carbon. The modification of the activated carbon was achieved by reaction between sodium hydroxide and surface phenol groups giving rise to phenolate groups (CoxONa), which were characterised by XPS, TG and TG-IR. Characterisation of immobilised manganese(III) salen catalysts onto CoxONa material by XPS, ICP-AES and TG-IR clearly point to reaction between carbon surface phenolate groups and the manganese(III) complexes through axial coordination of the metal centre to these groups.These materials were active and enantioselective in the epoxidation of styrene and a-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCl. Only for alpha-methylstyrene comparable asymmetric inductions were found in the epoxide as the homogeneous phase reactions and catalyst reuse led to no significant loss of catalytic activity and enantioselectivity. (C) 2005 Elsevier Ltd. All rights reserved.",

keywords = "activated carbon, chemically modified carbons, catalyst, catalyst support, catalytic properties, SALEN COMPLEXES, ENANTIOSELECTIVE EPOXIDATION, OLEFINS, IMMOBILIZATION, MODULATION, CHLORIDE, STYRENE",

author = "Silva, {A R} and V Budarin and Clark, {J H} and {de Castro}, B and C Freire",

year = "2005",

month = aug,

doi = "10.1016/j.carbon.2005.03.024",

language = "English",

volume = "43",

pages = "2096--2105",

journal = "CARBON",

issn = "0008-6223",

publisher = "Elsevier",

number = "10",

}

TY - JOUR

T1 - Chiral manganese(III) Schiff base complexes anchored onto activated carbon as enantio selective heterogeneous catalysts for alkene epoxidation

AU - Silva, A R

AU - Budarin, V

AU - Clark, J H

AU - de Castro, B

AU - Freire, C

PY - 2005/8

Y1 - 2005/8

N2 - Two chiral manganese(III) salen catalysts, bearing different chiral diamine bridges, were anchored by direct axial coordination of the metal centre onto the phenolate groups of a modified commercial activated carbon. The modification of the activated carbon was achieved by reaction between sodium hydroxide and surface phenol groups giving rise to phenolate groups (CoxONa), which were characterised by XPS, TG and TG-IR. Characterisation of immobilised manganese(III) salen catalysts onto CoxONa material by XPS, ICP-AES and TG-IR clearly point to reaction between carbon surface phenolate groups and the manganese(III) complexes through axial coordination of the metal centre to these groups.These materials were active and enantioselective in the epoxidation of styrene and a-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCl. Only for alpha-methylstyrene comparable asymmetric inductions were found in the epoxide as the homogeneous phase reactions and catalyst reuse led to no significant loss of catalytic activity and enantioselectivity. (C) 2005 Elsevier Ltd. All rights reserved.

AB - Two chiral manganese(III) salen catalysts, bearing different chiral diamine bridges, were anchored by direct axial coordination of the metal centre onto the phenolate groups of a modified commercial activated carbon. The modification of the activated carbon was achieved by reaction between sodium hydroxide and surface phenol groups giving rise to phenolate groups (CoxONa), which were characterised by XPS, TG and TG-IR. Characterisation of immobilised manganese(III) salen catalysts onto CoxONa material by XPS, ICP-AES and TG-IR clearly point to reaction between carbon surface phenolate groups and the manganese(III) complexes through axial coordination of the metal centre to these groups.These materials were active and enantioselective in the epoxidation of styrene and a-methylstyrene in dichloromethane at 0 degrees C using, respectively, m-CPBA/NMO and NaOCl. Only for alpha-methylstyrene comparable asymmetric inductions were found in the epoxide as the homogeneous phase reactions and catalyst reuse led to no significant loss of catalytic activity and enantioselectivity. (C) 2005 Elsevier Ltd. All rights reserved.

KW - activated carbon

KW - chemically modified carbons

KW - catalyst

KW - catalyst support

KW - catalytic properties

KW - SALEN COMPLEXES

KW - ENANTIOSELECTIVE EPOXIDATION

KW - OLEFINS

KW - IMMOBILIZATION

KW - MODULATION

KW - CHLORIDE

KW - STYRENE

U2 - 10.1016/j.carbon.2005.03.024

DO - 10.1016/j.carbon.2005.03.024

M3 - Article

SN - 0008-6223

VL - 43

SP - 2096

EP - 2105

JO - CARBON

JF - CARBON

IS - 10

ER -