C-C coupling reactions catalyzed by supported palladium in liquid phase [Elektronische Ressource] / Saeeda Shahid Soomro

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Informations

• Publié par: technische_universitat_munchen
• Publié le: 01 janvier 2009
• Nombre de lectures: 45
• Langue: Deutsch
• Poids de l'ouvrage: 5 Mo

Extrait

Department Chemie der Technische Universität München

C‐C Coupling Reactions Catalyzed by Supported Palladium 
in Liquid Phase 



Saeeda Shahid Soomro


Vollständiger Abdruck der von der Fakultät für Chemie der Technischen Universität
München zur Erlangung des akademischen Grades eines

Doktors der Naturwissenschaften

genehmigten Dissertation.

Vorsitzender: Univ.-Prof. Dr. Michael Schuster

Prüfer der Dissertation: 1. Univ.-Prof. Dr. Klaus Köhler
2. Univ.- Prof. Dr. Oskar Nuyken, i. R.


Die Dissertation wurde am 07.04.2009 bei der Technischen Universität München
eingereicht und durch die Fakultät für Chemie am 20.05.2009 angenommen.















“By three methods we may learn wisdom: First, by reflection,
which is noblest; Second, by imitation, which is easiest; and
Third, by experience, which is the bitterest.”
– Confucius


“All things are difficult before they are easy.”
– My father






















to Shahid

Die vorliegende Arbeit entstand in der Zeit von Februar 2006 bis März 2009 am
Anorganisch-chemischen Institut der Technischen Universität.

















Besonderer Dank gilt meinen akademischen Lehrer

Prof. Dr. Klaus Köhler

für die hervorragende Betreuung der Arbeit,
für das von Anfang an entgegengebrachte Vertrauen,
für die freundliche Aufnahme in seinem Arbeitskreis,
sowie sein großes Interesse am Gelingen der Arbeit.
ACKNOWLEDGEMENTS

I would like to start with special thanks to my advisor, Prof. Dr. Klaus Köhler, for
allowing me into his group and guiding me throughout my stay at TU Munich. His
continuous endorsement and insight have been crucial to both this thesis work and
my personal development. My special thanks are due to my co-supervisor Prof.
Farzana Latif Ansari from Quaid-e-Azam University, Islamabad (Pakistan) for her
kind approval and support she provided to start my PhD project. I acknowledge the
Bayerische Forschungsstiftung for generous research grant.

I am thankful to the past and current members of the Köhler research group. I would
like to express my sincere thanks to ex-colleagues in lab: Dr. Andreas Benetle, Dr.
Wolfgang Kleist, Dr. Barbara Müller and Dr. Thomas Endl, who were there to help
and support me when I joined the group. I am obliged to Dr. Oksana Storcheva for
the extra help she provided when I first arrived in Munich. Dr. Carmen Haessner,
Hans Beyer, and Konstantinos Chatziapostolou are acknowledged for their nice
company; I am also thankful to them for introducing various lab techniques. I am
thankful to my lab fellows Christoph Röhlich and Peggy Fredricks for pleasant
environment in the lab and useful scientific/non-scientific discussions.

Dr. Oksana Storcheva and Dr. Carmen Haessner are also acknowledged for their
help in EPR measurements. My sincere thanks are due to Ms. Ulrike Ammari for her
assistance in time consuming and tedious palladium determinations. Dr. Marianne
Hanzlik is acknowledged for the technical support she provided for TEM
measurements. I am obliged to Mr. Thomas Schröferl for his help in GLC
troubleshooting as well as his technical assistance in GC-MS measurements.

I thank all my friends who were always there to encourage me in hard times. Their
friendship and understanding are important to me. I would like to express my thanks
to my family too; my brothers, my sister and my father, whose love and feelings are a
continuous source of inspiration for me.

Very special thanks to my husband, Shahid whose insight, understanding,
encouragement and non-stop support made me able to fulfill this task.

I would like to thank my Creator for endowing me with life, the blessing of being able
to pursue a Ph.D., and for creating a world of such wonder that one can find joy in
simply trying to understand it.
Table of Contents
Table of Contents

1. Supported Palladium Catalysts for C-C Coupling Reactions: Problems and
Perspectives……………………………………………………………………………….. 1
1.1 General Itroduction…………………………………………………….. ………..2
1.2 Suzuki Coupling Reaction…………………………………………………………...5
1.2.1 Mechanism…………………………………………………………………. ….6
1.2.2 Catalytic Systems………………………………………………………………7
1.2.2.1 Ligand-free systems………………………………………………………7
1.2.2.2 Homogeneous catalysts………………………………………………….8
1.2.2.3 Supported catalysts……………………………………………………….9
1.2.3 Suzuki Coupling Reactions in Water……………………………………….. 13
1.3 Oxidative C-C Coupling Reactions……………………………………………. ...16
1.3.1 Mechanistic Details……………………………………………………. …….17
1.3.2 Catalytic Systems for Oxidative Coupling of Benzene (derivatives) with
Olefins…………………………………………………………………………………… 19
1.4 Aim of Work………………………………………………………………………….23
2. Suzuki Coupling Reactions……………………………………………………………..24
2.1 General Introduction………………………………………………………………..25
2.2 Suzuki Coupling Reactions in NMP/Water……………………………………….27
2.2.1 Suzuki Reactions of Aryl Bromides at 120 °C ………………………….…..27
2.2.1.1 Non-treated vs. treated catalysts ……………………………………….27
2.2.1.2 Comparison of different supported materials……………….…………28
2.2.1.3 Recycling experiments…………………………………………………..30
2.2.2 Suzuki Reactions of Aryl Chlorides at 120 °C………………………………30
2.2.3 Pd-leaching Investigations at 120 °C………………………………………..33
2.2.4 Suzuki Reactions of Aryl Bromides at 65 °C………………………………..35
2.2.4.1 Comparison of different Pd precursors………………………………...35
2.2.4.2 Influence of added water………………………………………………...36
2.2.4.3 Influence of the catalyst amount and pretreatment…………………..37
2.2.4.4 Scope of Pd/Al O catalyzed Suzuki coupling reactions at 65 °C…39 2 3
2.2.5 Suzuki Reactions of Aryl Chlorides at 65 °C……………………………….41
2.2.5.1 Influence of catalyst amount and pretreatment……………………….42
2.2.6 Pd-leaching Investigations at 65 °C…………………………………………43 Table of Contents
2.2.6.1 Kinetic experiments on correlation of Pd-leaching and conversion… 43
2.2.6.2 Palladium leaching as function of reaction parameters……………… 47
11 2.2.7 B NMR Experiment………………………………………………………… 50
2.2.8 TEM characterization of the catalyst before and after Suzuki coupling
reactions…………………………………………………………………………….. 53
2.2.9 Conclusive Remarks: Suzuki coupling reactions in NMP/water at 65 °C.. 55
2.3 Suzuki Coupling Reactions in Pure Water……………………………………… 57
2.3.1 General Introduction…………………………………………………………. 57
2.3.2 Pd/C Catalyzed Suzuki Coupling Reactions in Water under Mild
Conditions………………………………………………………………………….. 58
2.3.2.1 Variation of amount of water……………………………………………. 58
2.3.2.2 Substrate scope for Pd/C catalyzed Suzuki coupling reactions of aryl
bromides in water………………………………………………………………… 59
2.3.3 Pd/MOx Catalyzed Suzuki Coupling Reactions at 65 °C…………………. 59
2.3.3.1 Influence of metal oxide support………………………………………. 60
2.3.3.2 Variation of catalyst amount……………………………………………. 64
2.3.3.3 Optimization of reaction parameters………………………………….. 64
2.3.3.4 Pd/modified metal oxides catalyzed Suzuki coupling reactions of aryl
bromides in water………………………………………………………………… 65
2.3.4 Conclusive Remarks: Suzuki coupling reactions in water……………….. 66
3. Oxidative Coupling Reactions………………………………………………………… 67
3.1 General Introduction………………………………………………………………. 68
3.1.1 Screening of oxidants at different temperatures…………………………… 69
3.1.2 Time-dependant correlation of activity and selectivity in oxidative coupling
reactions……………………………………………………………………………… 71
3.1.3 Influence of molar excess of benzene and reaction atmosphere………... 72
3.1.4 Variation of oxidant amount…………………………………………………. 74
3.1.5 Varying the Pd-source in oxidative coupling reactions ………………….. 76
3.1.6 Conclusive Remarks: V O as oxidant for oxidative coupling reaction of 2 5
benzene and styrene ……………………………………………………….……..……77
3.1.7 Oxidative coupling of toluene with styrene using V O as oxidant……….79 2 5
3.2 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) as Potential Oxidant for
Oxidative Coupling Reactions………………………………………………………… 80
3.2.1 Variation of reaction conditions……………………………………………... 81 Table of Contents
3.2.2 Variation of Pd sources………………………………………………………. 81
3.2.3 Variation of oxidant amount…………………………………………………. 82
3.2.4 Variation of ligand and base…………………………………………………. 83
3.2.5 Conclusive Remarks: TEMPO as oxidizing agent………………………… 85
3.3 Investigations on Some Other Catalytic Systems for Oxidative Coupling
Reactions………………………………………………………………………………… 86
3.3.1 Pd/HPA catalytic system……………………………………………………... 86
3.3.2 Peroxides (tBuOOH or H O ) as oxidants…………………………………. 88 2 2