Organocatalytic additions to C=X bonds (X=O, C, and NR) [Elektronische Ressource] / vorgelegt von Zhiguo Zhang

Informations

• Publié par: justus-liebig-universitat_giessen
• Publié le: 01 janvier 2008
• Nombre de lectures: 29
• Langue: Deutsch
• Poids de l'ouvrage: 2 Mo

Extrait

Organocatalytic Additions to C=X
Bonds (X=O, C, and NR)






Inaugural-Dissertation zur Erlangung des Doktorgrades
der Naturwissenschaftlichen Fachbereiche
(Fachbereich 08 – Biologie und Chemie)
der Justus-Liebig-Universität Giessen




vorgelegt von
Zhiguo Zhang
geb. am 27-12-1977 in Henan, China









eingereicht beim Fachbereich 08
der Justus-Liebig-Universität
Giessen 2008
Die vorliegende Arbeit wurde in der Zeit von Oktober 2004 bis Dezember 2007 am Institut für
Organische Chemie der Justus-Liebig Universität Giessen unter der Anleitung von Herrn Prof. Dr.
Peter. R. Schreiner, Ph.D. durchgefürt.














































An dieser Stelle möchte ich Herrn Prof. Dr. P. R. Schreiner für die Anregungen zu diesem
Thema, sein stetes Interesse am Fortgang dieser Arbeit, die ausgezeichneten
Arbeitsbedingungen und zahlreichen fördernden Diskussionen danken.
















































Für meine Frau Dan Li






This thesis is based on the following publications and manuscripts:



I. Organocatalytic Reactions Mediated through Thiourea Derivatives

Zhiguo Zhang, Peter R. Schreiner*

The introduction of this thesis is written as part of a review for Chem. Soc. Rev. and will be
submitted soon.

II. Thiourea-Catalyzed Transfer Hydrogenation of Aldimines

Zhiguo Zhang, Peter R. Schreiner*

Synlett 2007, 1455–1457.

III. Organocatalytic Biomimetic Reduction of Conjugated Nitroalkenes

Zhiguo Zhang, Peter R. Schreiner*

Synthesis 2007, 2559–2564.

IV. Trichlorosilane (HSiCl ) – A Cheap and Convenient Reducing Agent 3

Zhiguo Zhang

Submitted to Synlett Spotlight on Jan. 9, 2008.

V. Organocatalytic Reduction of Imine Using Trichlorosilane as the
Hydrogen Donor (Manuscript in preparation)

VI. Development of Thiourea-Catalyzed Cyanosilylation (Manuscript in
preparation)

VII. Development of Organocatalytic Hydrophosphonylations
(Manuscript in preparation)
Table of Contents

Summary .................................................................................................................. i
Zusammenfassung ................................................................................................... iii
Chapter 1 Introduction and State-of-the-Art ...................................................... 1
1.1 Organocatalysis............................................................................................... 1
1.2 Organocatalysis mediated through hydrogen bonding ................................... 2
1.3 Organocatalysts based on ureas and thioureas................................................ 3
1.3.1 General evolutions from biphenylenediols to efficient
N,N’-diarylthio(urea) catalysts................................................................ 3
1.3.2 Chiral (thio)ureas for asymmetric organocatalysis ................................. 5
1.3.2.1 Double hydrogen-bond-donor (thio)ureas....................................... 6
1.3.2.2 Chiral bifunctional (thio)ureas for asymmetric organocatalysis ..... 9
1.3.3 Conclusions and outlook......................................................................... 23
1.4 Organocatalyzed transfer hydrogenation with Hantzsch ester
as the hydrogen source................................................................................... 23
1.4.1 Introduction.............................................................................................23
1.4.2 Developments and applications .............................................................. 24
1.4.3 Summary and outlook ............................................................................. 31
1.5 Organocatalytic reduction with trichlorosilane............................................... 31
1.5.1 Introduction.............................................................................................31
1.5.2 Developments and applications 32
1.5.3 Summary.................................................................................................40
1.6 Organocatalyzed asymmetric cyanosilylation ................................................ 40
1.6.1 Introduction.............................................................................................40
1.6.2 Synthesis of racemic cyanohydrins with green approaches.................... 41
1.6.3 Asymmetric synthesis of cyanohydrins with TMSCN catalyzed by
organocatalysts........................................................................................ 42
1.6.4 Conclusions and outlook......................................................................... 46
Chapter 2 Research Objectives ............................................................................. 47
Chapter 3 Organocatalytic Reductions ................................................................ 48
3.1 Thiourea-Catalyzed Transfer Hydrogenation of Aldimines ........................... 51
Published as: Zhiguo Zhang and Peter R. Schreiner Synlett 2007, 1455–1457 ..........................51
3.2 Organocatalytic Biomimetic Reduction of Conjugated Nitroalkenes.............55
Published as:
Zhiguo Zhang and Peter R. Schreiner Synthesis 2007, 2559–2564 ......................55
3.3 Miscellaneous..................................................................................................
3.4 Trichlorosilane (HSiCl ) – A Cheap and Convenient Reducing Agent..........65 3
Submitted for publication
Zhiguo Zhang Synlett Spotlight.............................................................................65
3.5 Asymmetric Organocatalyzed Reduction of Ketimines with HSiCl .............67 3
Manuscript in preparation
Chapter 4 Development of Thiourea-Catalyzed Cyanosilylation.......................76
Chapter 5 Development of Organocatalytic Hydrophosphonylations...............84
Chapter 6 Summary and Outlook .........................................................................89
Chapter 7 Experimental Section............................................................................92
7.1 Chemicals and solvents ...................................................................................92
7.2 Instrumentation and methods ..........................................................................93
7.3 Synthesis of N-formamides .............................................................................95
7.4 Synthesis of oxazoline thioureas.....................................................................105
7.5 Synthesis of bifunctional thioureas .................................................................113
7.6 Synthesis of Schiff-base thioureas ..................................................................117
7.7 NMR Spectra...................................................................................................123
Appendix I List of Symbols and Abbreviations ................................................167
Appendix II Compounds Index ............................................................................169
Acknowledgement ....................................................................................................171
Curriculum Vitae .....................................................................................................173