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  • SYNTHESIS AND REACTIVITY

    OF PENTAMETHYLCYCLOPENTADIENYL RHENIUM

    ALLYL COMPLEXES

    Yingxia He

    B.Sc. Heilongjiang University (China), 1982

    M.Sc. Heilongjiang University (China), 1986

    A THESIS SUBMITTED IN PARTIAL FULFILMENT OF '

    THE REQUIREMENTS FOR THE DEGREE OF

    DOCTOR OF PHILOSOPHY

    in the Department

    of

    Chemistry

    O Yingxia He 1995

    Simon Fraser University

    November 1995

    All rights reserved. This work may not be

    reproduced in whole or in part, by photocopy

    or other means, without permission of the author.

  • APPROVAL

    Name: Yingxia He

    Degree: Ph.D. Chemistry

    Title of Thesis: Synthesis and Reactivity of Pentamethylcyclopentadienyl Rhenium

    Ally1 Complexes

    Examining Committee:

    Chairperson: S. Wolfe, Professor

    D. Sutton, Senior super vlsor, Professor

    L. K. Peterson, Associate Professor

    F. W. B. Einstein, Professor Internal Examiner

    J. M. Mayer, Professor External Examiner Department of Chemistry University of Washington

    Date Approved: (v &w

  • PARTIAL COPYRIGHT LICENSE

    I hereby grant to Simon Fraser University the right to lend my thesis,

    project or extended essay (the title of which is shown below) to users of the

    Simon Fraser University Library, and to make partial or single copies only for

    such users or in response to a request from the library of any other university, or

    other educational institution, on its own behalf or for one of its users. I further

    agree that permission for multiple copying of this work for scholarly purposes

    may be granted by me or the Dean of Graduate Studies. It is understood that

    copying or publication of this work for financial gain shall not be allowed

    without my written permission.

    Title of Thesis/Project/Extended Essay:

    Svnthesis and Reactivity of Pentamethylcvclo ntadienvl Rhenium Allvl Complexes

    Author:

    (signature)

    Decp?wLu (41 / Y M (date)

  • ABSTRACT

    The thesis describes the synthesis, characterization, and reactivity investigation of

    the new rhenium pentamethylcyclopentadienyl allyl complexes of the general formula

    [c~*R~(~~-c~Hs)LL'][BF~] (L = L' = CO, CH3CN, CH3CH2NH2; L = CO, L' = CH3CN,

    CH3CH2NH2; L = PMe3, L' = CH3CN, CH3CH2NH2) and C ~ * R ~ ( ~ ~ - C ~ H ~ ) ( C O ) L (L = C1,

    H, and alkyl group). [c~*R~(~~-c~Hs)(co)~][BF~] (2.1) was successfully synthesized in a

    photochemical reaction by irradiating CP*R~(CO)~ in the presence of allyl alcohol and

    HBF4 in ether solution. Its derivatives, the mono- and bis- pentarnethylcyclopentadienyl

    acetonitrile allyl rhenium complexes [c~*R~(~~-c~H~)(co)(NccH~)][BF~] (2.2) and

    [c~*R~(~~-c~Hs)(NccH~)~][BF~] (2.3) have been made, and the X-ray crystal structures

    of these compounds have been obtained.

    The reactivity of complex 2.1 with various nucleophiles has been studied. C~HSS',

    C6H5S-, -SCH2CH2CH2S-, NH2-, N3-, CH3COO-, and Me2CHMgBr reacted with 2.1 at 0

    -20 "C by attacking the allyl ligand to give substituted propene compounds. When 2.1 was

    treated with PhLi, or CH30- at 0 "C, both the allyl and the CO ligands were attacked to

    give complexes C~*R~(CO)~(~~-CH~CHCH~R) and C~*R~(CO)(~~-C~HS)(COR), but the

    substituted propene product is thermodynamically preferred.

    The reactions of complexes 2.2 and 2.3 with NaBH4, PMe3 and NaOMe (or

    NaOH) were investigated. For complexes 2.2 and 2.3, NaB& reduced the coordinated

    acetonitrile ligand to ethylamine; PMe3 underwent nucleophilic attack on the allyl group in

    2.2 to generate the corresponding phosphonium compound, or substituted one acetonitrile

    ligand in 2.3 to produce the PMe3 complex.

    Irradiation of CP*R~(CO)~ under UV light with allyl chloride was investigated in

    order to discover a method of synthesizing C ~ * R ~ ( ~ ~ - C ~ H S ) ( C O ) C ~ (5.1). Complex 5.1

    was also obtained by treating complex 2.1 with PhIO in CH2Cl2 in the presence of

    Me4NCl, and this is an efficient method compared with the photochemical reactions of

  • Cp*Re(CO)3 with ally1 chloride. Complex 5.1 reacted with C6H5Li or RMgX (R = CH3,

    C2H5, GHs, X = Br; R = C4H9, X = C1) to give complexes c ~ * R ~ ( ~ ~ - c ~ H s ) ( c o ) R (5.8 -

    5.12). The reactivities of these rhenium allyl alkyl compounds have also been studied.

    Complex 5.1 reacted with LiBEt3H in dry ether to provide an alternative

    convenient route for the synthesis of the rhenium hydrido compound cp*Re(q3-

    C3H5)(CO)H (5.7). The reactions of this complex towards H', ArN2', NO', PhK+, PMe3,

    CH3CsC6H5, CH3CN, C2&, C6HIo, C6H12 and CO have been investigated. The

    protonation of complex 5.7 with CF3C02H and CF3S03H in various solvents occurred at

    the metal center to give the dihydride intermediates, followed by a migration of H to the

    coordinated allyl to give the propene complexes c ~ * R ~ ( c o ) ( H ) ( ~ ~ - c ~ H ~ ) L (L = CF3CO:!

    or CF3S03). A variable temperature NMR study of these protonation reactions indicated

    the existence of the dihydride intermediates.

  • DEDICATION

    To my parents, my husband Daqing and my daughter Karina Bo

  • ACKNOWLEDGMENTS

    I would like to thank my supervisor Dr. Derek Sutton for his patient guidance and

    assistance during my research work and thesis writing. I appreciate the time he spent for

    many of our discussions, and the happy working environment he provided for my graduate

    study.

    It has been a pleasure to associate with Dr. Louis Peterson, Dr. Fred Einstein and

    Dr. Raymond Batchelor, whose expert advice has proven greatly helpful.

    I thank Drs. X. Yan, N. Lowe, C. Leiva-Paredes and A. Cusanelli for the useful

    discussion, M. M. Tracey for her efficient service of obtaining the NMR spectra, G. L.

    Owen for providing the mass spectra, M. Yang for providing the microanalyses, and F.

    Chin for his help in using computer system.

    I also thank S. Blair and Dr. H. Davis for proof reading part of this thesis.

    I appreciate the encouragement and support of my husband, my parents and

    parents in law.

  • TABLE OF CONTENTS

    Page Number

    . . ............................................................................................................... Approval Page.. 11

    Partial Copyright License ................................................................................................... ... ......................................................................................................................... Abstract .m

    Dedication ..................................................................................................................... v ........................................................................................................ Acknowledgments.. vi

    . . Table of Contents ........................................................................................................... VII

    . . List of Abbreviations and Symbols ................................................................................ xvll List of Complexes ..................................................................................................... xviii

    List of Figures ............................................................................................................... xx

    List of Schemes ........................................................................................................... xxii

    List of Tables ............................................................................................................. xxiv

    Chapter I: Transition Metal Allyl Complexes and Their Applications in

    Organic Synthesis

    1.1. Introduction .......................................................................................... 1 .................................................................................... 1.2. Allyl-Metal Bond 4

    1.3. Syntheses of q3-Allyl Transition Metal Complexes .................................. 8

    1.3.1. Reactions of Metal Halide Compounds with Grignard

    Reagents ...................................................................................... .8

    1.3.2. Oxidative Addition of Ally1 Halides .............................................. 9 ................................................... 1.3.3. From Metal Olefin Complexes.. 9

    .................................. 1.3.4. Reactions of 1,3-Diene Metal Complexes. 10 I 3 .................................. 1.3.5. Rearrangement of q to q Ally1 Complex 1 1

  • 1.3.6. Other Reported Methods ............................................................ 1 1

    1.4. Application of Transition Metal Allyl Complexes in Organic

    Synthesis ............................................................................................... 13

    1.5. Research Background for the Thesis Project ......................................... 15

    1.6. Our Contributions to q 3 - ~ 1 1 ~ 1 Rhenium Chemistry ............................... 17

    Chapter 11: Synthesis and Characterization of Pentamethylcyclopentadienyl Rhenium

    Allyl Complexes [Cp*Re(q3-c~I&R)LL'][

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