Preparation of functionalized organomagnesium Reagents by ortho-magnesiation, sulfoxide-, iodine- and bromine-magnesium exchange reactions [Elektronische Ressource] / Christian Bernhard Rauhut

Christian Rauhut

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2008
• Nombre de lectures: 20
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Dissertation zur Erlangung des Doktorgrades
der Fakultät für Chemie und Pharmazie
der Ludwig-Maximilians-Universität München








Preparation of Functionalized Organomagnesium
Reagents by ortho-Magnesiation,
Sulfoxide-, Iodine- and Bromine-Magnesium
Exchange Reactions.











Christian Bernhard Rauhut




aus





München




2008
ii

iii


Erklärung
Diese Dissertation wurde im Sinne von § 13 Abs. 3 der Promotionsordnung vom 29.
Januar 1998 von Professor Dr. Paul Knochel betreut.








Ehrenwörtliche Versicherung
Diese Dissertation wurde selbstständig, ohne unerlaubte Hilfe erarbeitet.



München, am 06.12.2007















Christian Bernhard Rauhut






Dissertation eingereicht am 30.10.2008
1. Gutachter: Prof. Dr. Paul Knochel
2. Gutachter: Prof. Dr. Manfred Heuschmann
Mündliche Prüfung am 10.12.2008
iv
This work was carried out from November 2005 to October 2008 under the guidance of
Prof. Knochel at the Fakultät für Chemie und Pharmazie der Ludwig-Maximilians-
Universität, Munich.



I would like to thank Prof. Dr. Paul Knochel, for giving me the opportunity of doing my
Ph.D.in his group, for his support and for his guidance in the course of my scientific
research.

I am also very grateful to Prof. Dr. Manfred Heuschmann for agreeing to be my
“Zweitgutachter”, as well as Prof. Dr. I. P. Lorenz, Prof. Dr. H. Langhals, Prof. Dr. H.
Zipse and Prof. Dr. H. R. Pfaendler for the interest shown in this manuscript by
accepting to be referees.


I thank Georg Manolikakes, Albrecht Metzger, Fabian Piller, Christoph Rohbogner and
Stefan Wunderlich for the careful correction of this manuscript.


I thank all past and present co-workers I have met in the Knochel’s group for their
kindness and their help. Special thanks to Dr. Murthy Cheemala, Dr. Srinivas Dubbaka
and his wife Thresen, Dr. Ching-Yuan Liu and his wife Chaofang for some special
lectures in asian cooking and culture.


I would like to thank Laurin Melzig for fruitful collaboration in the sulfoxide chemistry,
and my lab F2.004 for not complaining too much about my sulfur chemistry and for all
the fun we had.


I would also like to thank Beatrix Cammelade,Vladimir Malakov, Simon Matthe, and
Yulia Tsvik for their help in organizing everyday life in the lab and in the office, as well
as the analytical team of the LMU for their invaluable help.


Special thanks to the БЦТИА Д-crew, who helped me a lot keeping my fine motoric
skills on a high level, and all the people who joined our out-door and sportive activities.


Very special thanks to my family and to Kathrin for their love and endless support.

v
Parts of this Ph. D. thesis have been published:


1) Christian B. Rauhut, Viet Anh-Vu, Frasier F. Fleming, Paul Knochel, „Preparation of
Functionalized Alkylmagnesium Derivatives Using an I/Mg-Exchange”, Org. Lett.
2008, 10, 1187.
2) Christian B. Rauhut, Laurin Melzig, Paul Knochel, „Meta- and Para-
Difunctionalization of Arenes via a Sulfoxide-Magnesium Exchange Reaction”,
Org. Lett. 2008, 10, 3891.
3) Laurin Melzig, Christian B. Rauhut, Paul Knochel, „Meta-and Para-
Difunctionalization of Arenes via a Ortho-Magnesiation and a Subsequent
Sulfoxide-Magnesium Exchange”, Synthesis 2009, manuscript in press.
4) Christian B. Rauhut, Christian Cervino, Arkady Krasovskiy, Paul Knochel,
„Stereoselective Preparation of Cyclopropylmagnesium Reagents via Br/Mg-
exchange using iPrMgCl·LiCl in the Presence of Dioxane”, Synlett 2009, 67.
5) Christian B. Rauhut, Laurin Melzig, Paul Knochel, „Functionalization of Furan and
Thiophene via ortho-Magnesiation and Subsequent Sulfoxide-Magnesium Exchange
Reaction”, manuscript in preparation.

vi








to Kathrin, my love. vii

1. Introduction ................................................................................................................ 1
1.1. Preparation of organomagesium reagents ........................................................ 2
1.1.1. Direct oxidative insertion of magnesium in organic halides..................... 2
1.1.2. Halogen-magnesium exchange reactions.................................................... 3
1.1.3 ortho-Magnesiation with magnesium amides.............................................. 7
1.1.4. Sulfur-magnesium exchange reaction......................................................... 9
1.1.5. Sulfoxide-magnesium exchange reaction ................................................. 10
1.2. Objectives ........................................................................................................... 14
2. Results and Discussion ............................................................................................. 16
2.1. Sulfoxide-magnesium exchange on aromatic systems.................................... 16
2.2. Full functionalization of the furan ring ........................................................... 33
2.3. I/Mg-exchange on Csp3-centers ....................................................................... 37
2.4. Br/Mg-Exchange on cyclopropylbromides...................................................... 46
3. Summary and outlook.............................................................................................. 50
3.1 Sulfoxide-magnesium exchange on aromatic systems..................................... 50
3.2. Full functionalization of the furan ring 51
33.3. I/Mg-exchange on Csp -centers........................................................................ 51
3.4. Br/Mg-Exchange on cyclopropyl bromides..................................................... 52
4. Experimental section ................................................................................................ 54
4.1. General considerations...................................................................................... 54
4.1.1. Solvents........................................................................................................ 54
4.1.2. Chromatography ........................................................................................ 54
4.1.3. Analytical Data ........................................................................................... 55
4.1.4. Reagents....................................................................................................... 56
4.1.5. Non-commercial available Grignard-reagents ........................................ 57
1,5-Bis(chloromagnesio)pentane (43c) .............................................................. 57
2-Bromomagnesio propane(d ) (51)................................................................... 57 7
1,6-Bis(chloromagnesio)hexane (77a) ............................................................... 58
2,6-Bis(chloromagnesio)heptane (77b) 58
2,7-Bis(chloromagnesio)octane (77c) ................................................................ 59
1,3-Bis(chloromagnesiomethyl)cyclopentane (77d) .......................................... 59
1,5-Bis(bromomagnesio)-3,3-dimethyl-pentane (77e)....................................... 60
4.2. Typical procedures ............................................................................................ 61
Typical Procedure for preparation of sulfoxides of type 37 with the pNMe C H -2 6 4
ligand (TP1):....................................................................................................... 61
Typical procedure for preparation of sulfoxides of type 37 with the pMeOC H -6 4
ligand (TP2): 61 37 using the sulfinate 45
(TP3):.................................................................................................................. 62
Typical procedure for deprotonation of sulfoxides and Negishi type cross-
coupling reactions (TP4): ................................................................................... 62
Typical procedure for the sulfoxide-magnesium exchange leading to arenes of
type 53 (TP5):..................................................................................................... 62 agnesium exchange leading to furans of
type 61 (TP6): 63
Typical procedure for the iodine-magnesium exchange leading to furans of type
62 (TP7):............................................................................................................. 63
Typical procedure for the bromine-magnesium exchange leading to
cyclopropanes of type 83a–d (TP8): .................................................................. 64 viii
Typical procedure for the bromine-magnesium exchange leading to
cyclopropanes of type 83e–f (TP9): ................................................................... 64
4.3. Preparation of functionalized organomagnesium re