Aspects of Homogeneous Catalysis

208 Pages·1981·4.908 MB·English

by  Roger A. Sheldon (auth.), Renato Ugo (eds.)

ASPECTS OF HOMOGENEOUS
CATALYSIS
Volume 4
ASPECTS OF
HOMOGENEOUS
CATALYSIS
A Series of Advances
EDITED BY
RENATO UGO
I STITt ITO DI CHIMICA GENERALE ED INORGANICA
(INIYERSITA DI MILANO
VOLUME 4
D. REIDEL PUBLISHING COMPANY
DORDRFCHI HOLL\ND BOSTON. U.SA LONDON. ENGLAND
The Library of Congress Cataloged the First Issue of this Work as Follows:
Ugo, Renato (ed.)
Aspects of homogeneous catalysis. vol. I.
1970-
Milano, C. Manfredi.
v. illus. 25 em. annual.
'A Series of Advances'.
Editor: 1970- R. Ugo.
I. Catalysis-Periodicals. 1. Ugo, Renato (ed.).
QD501.A83 541 '395 72-623953
ISBN-13: 978-94-009-8373-1 e-ISBN-13: 978-94-009-8371-7
DOl: 10.1007/978-94-009-8371-7
Published by D. Reidel Publishing Company,
P.O. Box 17, 3300 AA Dordrecht, Holland
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All Rights Reserved
Copyright © 1981 by D. Reidel Publishing Company, Dordrecht, Holland
Softcover reprint of the hardcover 1st edition 1981
No part of the material protected by this copyright notice may be reproduced or
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Editorial Board
L. Vaska
The Clarckson College of Technology (U.S.A.)
E. W. Stern
Engelhard Industries (U.S.A.)
B. L. Shaw .
The University of Leeds (U.K.)
A. Sacco
The University of Bari (Italy)
G. Pregaglia
Montecatini-Edison S.p.A. (Italy)
B. James
The University of British Columbia (Canada)
L. Marko
University of Chemical Industries Academy of Science (Hungary)
M. Volpin
Institute of Organo-Element Compounds Academy of Science (USSR)
A. Misono
University of Tokyo (Japan)
J. Tsuji
Tokyo Institute of Technology (Japan)
J. Garnett
University of New South Wales (Australia)
H.Mimoun
Institut Fran9ais du Petro Ie (France)
W. Keirn
Institut fUr Technische Chemie und Petrolchemie (W. Germany)
P. Maitlis
Sheffield University (England)
J. Roth
Air Products and Chemicals Inc. (U.S.A.)
Contents of Volume 4
Metal-Catalysed Epoxidations of Olefins with Hydroperoxides 3
Roger A. Sheldon
1. Introduction 4
2. Metal-Catalysed Epoxidations with Hydrogen Peroxide 6
3. Covalent Metal Peroxides as Epoxidizing Agents 13
4. Metal-Catalysed Epoxidations with Alkyl Hydroperoxides 17
5. Oxidation of other Functional Groups 60
6. Summary 63
7. Glossary of Non-Standard Abbreviations 64
8. References 64
Homogeneous Catalytic Reduction of Carbonyl-. Azomethine-. and
Nitro-Groups 71
G. Mesironi. A. Camus. and (i. Zassill()vich
I. Introduction 71
2. Reduction of the Carbonyl Group 73
3. Reduction of Schiff Bases 85
4. Reduction of Nitro-Compounds 86
5. Dihydrogen Evolution 88
6. Reaction Mechanisms 90
7. Conclusions 95
8. Abbreviations for Ligand Names 96
9. References 96
Catalysis of Diolefin Reactions by 1J.1-Allyl :vJetal Complexes 99
M. Julemolll and Ph. Terssi(;
I. Introduction 100
vii
V III Contents
2. Allyl-MT Complexes: Bonding and Dynamic Behaviour 100
3. Oligomerisation. Co-Oligomerisation and Polymerisation of Diolefins 110
4. Relation between Catalyst Structure and Kinetic and Thermodynamic Controls of
Butadiene Oligo-and Polymerisation Processes 126
5. lsomerisation of Diolefins 133
6. Heteroactivation of Diolefins 136
7. Conclusions 140
8. References 141
Substrates and Phosphorus Ligands Used in Asymmetric Homogeneous
Hydrogenations Catalysed by Rhodium Complexes 145
UlSzlo Marko and Jo~.wfBakos
I. Introduction 145
Tahle I' Chiral phosphines used as ligands in the rhodium-catalysed asymmetric
hyd rogenation 147
Tahle :!: Substrates in the rhodium-catalysed asymmetric hydrogenation 174
2. References 200
Index 203
ASPECTS OF HOMOGENEOUS
CATALYSIS
Volume 4
MetaI-CataIysed Epoxidations of Olefins
with Hydroperoxides
ROGER A. SHELDON
Koninklijke Shell LaboralOrium. Amsterdam
1. Introduction 4
2. Metal-Catalysed Epoxidations with Hydrogen Peroxide 6
2.1. CATALYSTS AND CONDITIONS 6
2.2. THE MECHANISM 8
2.3. SCOPE AND LIMIT AT IONS 9
3. Covalent Metal Peroxides as Epoxidizing Agents 13
4. Metal-Catalysed Epoxidations with Alkyl Hydroperoxides 17
4.1. HISTORICAL DEVELOPMENT 17
4.2. FACTORS GOVERNING CATALYST ACTIVITY AND SELECTIVITY 19
4.3. BY-PRODUCTS AND THEIR ORIGINS 25
4.4. HOMOGENEOUS VERS(!S HETEROGENEOUS CATALYSIS 26
4.4.1. General Considerations 26
4.4.2. Coordination Complexes as Catalysts-Ligand Effects 26
4.4.3. Metal Oxide-Based Catalysts-The Effect of Supports 28
4.5. KINETICS OF EPOXIDATIONAUTORETARDATION BY THE COPRODUCT
ALCOHOL 32
4.6. THE MECHANISM OF OXYGEN TRANSFER 34
4.7. SOLVENT EFFECTS 38
4.8. EFFECT OF STRUCTURE OF THE HYDROPEROXIDE 39
4.9. TEMPERATURE 41
4.10. EFFECT OF OLEFIN STRUCTURE ON REACTIVITY 41
4.11. SCOPE IN ORGA!\ij(' SYNTHESIS: REGIO- AND STEREOSELECTIVITY 44
3
4 Epoxidation of olefins
4.12. ASYMMETRIC EPOXIDATION 54
4.13. HYDROXYKETONIZA TION 55
4.14. IN-SITU GENERATION OF THE HYDROPEROXIDE-SINGLE STAGE
EPOXIDA TION 56
4.15 POSSIBLE INDUSTRIAL APPLICATIONS 57
5. Oxidation of Other Functional Groups 60
6. Summary 63
7. Glossary of Non-standard Abbreviations 64
8. References 64
1. INTRODUCTION
Epoxides, particularly ethylene and propylene oxide, are extremely impor
tant building blocks in the petrochemical industry. They are the raw materials
for a wide variety of chemicals, such as glycols and alkanolamines, and polymers,
such as polyesters, polyurethanes and epoxy resins [1-5].
The simplest member of the series, ethylene oxide, is prepared industrially
by gas phase oxidation of ethylene with air or oxygen over a supported silver
catalyst [6,7], a reaction first observed by Lefort [8] in 1933. Unfortunately, this
method is not generally applicable. Higher olefins react under these conditions
to give only very low yields of epoxides. Many attempts have been made to
develop a commercially viable vapour phase oxidation process for the manufac
ture of propylene oxide but the maximum yield obtainable is around 25% and a
plethora of by-products is formed. Even if such low yields were acceptable, the
separation and disposal of these by-products would present an almost insuperable
obstacle to commercialization.
Propylene oxide producers have generally relied on the older chlorohydrin
technology, once employed extensively for ethylene oxide manufacture [2,3,9]. In
this process addition of hypochlorous acid to propylene affords a chlorohydrin,
which is converted to propylene oxide by treatment with a base, such as milk of
lime.
+
MeCH =CH2 HOCI MeCH(oH)CH2CI
o
/"
MeCH-CH2 + CaCI2 (2)
The process suffers from the drawbacks that rather dilute solutions have to
be used and that several chlorinated by-products are formed. In recent years
there has been, for environmental reasons, a general shift away from chlorine
based processes.
Introduction 5
Another approach is via the peracid route [10,Il], whereby propylene is
epoxidized by an organic peracid, usually peracetic acid. The latter is prepared
either by reaction of acetic acid with hydrogen peroxide, or by autoxidation of
acetaldehyde.
-
-
(3)
---I....
MeCHO +02 MeC03H (4)
°
/'\.
MeC03H + MeCH=CH2 ---I.. .. MeCH-CH2+ MeC02H (5)
Although this method has been extensively studied [10, II] and is often the
method of choice for laboratory scale preparations of epoxides, it has not been
widely applied on a commercial scale. The reasons are probably to be found in the
hazards associated with the handling of these explosive and corrosive peracids
on an industrial scale. Nevertheless, several companies continue to groom this
method for future commercialization [12].
With organic hydroperoxides becoming available as commercial chemicals,
in the last decade propylene oxide process technology has seen the commercializa
tion of the hydroperoxide route. Such a process, developed by Halcon Interna
tional and Atlantic Richfield, is that often referred to as the Halcon or Oxirane
process [13]. It involves the reaction of propylene with an alkyl hydroperoxide in
the presence of a soluble, metal catalyst (usually a molybdenum compound).
The alkyl hydroperoxide is prepared by autoxidation of an appropriate hydro
carbon. For example, tert-butyl hydroperoxide (TBHP) is prepared by autoxida
tion of isobutane.
(6)
Reaction with propylene gives propylene oxide and tert-butanol as a coproduct.
The latter is dehydrated to isobutene, which is sold as such or recycled after
hydrogenation.
0\
/
catalyst
Me3COOH + MeCH=CH2 • MeCH-CH2 + Me3COH (7)
If ethylbenzene is used as the hydroperoxide precursor the second stage of the
process may be written:
/0\
catalyst
PhCH(Me)OOH + MeCH=CH2 • MeCH-CH2 + PhCH{Me)OH (S)