Alkene, hydrido(allyl) and metal-metal bonded derivatives of rhenium

290 Pages·2006·3.36 MB·English

ALKENE, HYDRIDO (ALLYL) AND METAL-METAL BONDED
DERIVATIVES OF RHENIUM
Jun-Ming Zhuang
B.Sc., Fudan University, Shanghai, China, 1982
M.SC., Shanghai Institute of Organic Chemistry,
Academia Sinia, 1984
THESIS SUBMITTED IN PARTIAL FULFILLMENT OF
THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
in the Department
L
of
Chemistry
@
Jun-Ming Zhuang 1990
SIMON FRASER UNIVERSITY
June, 1990
A l l rights reserved. This work may not be
reproduced in whole or in part, by photocopy
or other means, without permission of the author.
ii
APPROVAL
Name: Jun-Ming Zhuang
Degree: DOCTOR OF PHILOSOPHY
Title of Thesis: Alkene, Hydrido(ally1) and Metal-Metal Bonded Derivatives of
Rhenium
Examining Committee:
Chairman: Dr. P. W. Percival
Dr. D. Sutton, Sehior Supervisor
.-
Dr. F. W. B. in stein, Supervisory Committee
Dr. A. C. Oehlschlager, SGpervisory Committee
Dr. L. K. Peterson, Internal Examiner
Dr. P. M. Boorman, External Examiner
Department of Chemistry
University of Calgary
{"lo
Date Approved:
PARTIAL COPYRIGHT LICENSE
I hereby grant to Simon Fraser University the right to lend
my thesis, project or extended essay (the t i t l e 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
ALKENE, HYDRIDO(ALLYL) AND METAL-METAL BONDED DERIVATIVES
OF RHENIUM.
Author:
(signature)
Jun-Ming Zhuang
(name)
3 October 1990
(date)
ABSTRACT
This thesis describes an investigation of the chemical
reactions displayed by the 168- active intermediate [C~*R~(CO1) ~
with linear or cyclic alkenes, and the neutral electron-donor
complex Cp* Ir(C0)2. The relevant new reactions and derivatives have
been determined as illustrated by the following:
The new alkene rhenium complexes of general formula
- -
CpfRe(CO) (alkene)~~( L1 CO, PMe3 ; alkene ethene, propene, 2-
pentene, 1-octene, cis-2-octene,c yclohexene, 4-methylcyclohexene,
cyclooctene, allene, 1,3-cyclohexadiene, 1,4-cyclohexadiene) have
been synthesized by several different methods: (1) the photochemical
-
reactions of C~*R~(CO)L~Q (L1 = CO, PMe3 ; L2 CO, N2) with
alkenes ; (2) the thermal reaction of c ~ *(R~~0 (T)HF~) with allene;
(3) the reaction of the cationic q3 -ally1 com2lexes with sodium
borohydride or sodium methoxide. The allene rotation and 1,2-shift
-
(from one double bond to the other) in the complex C~*R~(CO(r)12 ~
allene) have been investigated. The activation parameters for the
z-allene rotation determined by temperature-dependent lH NMR
- -
+ +
experiments are: AG* 9.9 0.2 kcal/mol ( -50' C) , AH* 10.9 0.3
+
kcal/mol and AS* = 4.7 1.4 cal/K.mol. Saturation- transfer
experiments at 100'~ indicated that the 1,2-shift occurs with a
large activation barrier.
The photochemical C-H activation of the coordinated alkenes
in c~*R~(co()t)~' -alkene) complexes has been investigated for a range
of linear and cyclic alkenes. Two types of photochemical C-H
activation of alkenes in cp*Re systems have been discovered: (1) the
intramolecular allylic C-H activation of linear alkenes to give
rhenium ally1 hydride complexes; (2) the photochemical double C-H
activation of coordinated cyclohexene, and the formation of
- - .
~ pR*e (CO) (q2 1,3 cyclohexadiene)
Photolysis of the propene complex cp* ~e (~0(q)2 ~-p ropene)
.
produced two isomers exo and endo c~*R~(co)(H ) (q3 -allyl) An
irreversible conversion from exo to endo occurs under thermal
conditions, and the estimate of the Arrhenius activation energy
-
.
gives a value E, 28.9 2 3.2 kcal.mo1-' Irradiation favours the
reverse conversion from endo to exo.
The t)3 -allylalkane cationic complexes of general formula
[~pR*e ( ~ 0(q)3 ~-a llylalkane)] [BF4 ] were produced by three different
routes : (1) the allylic hydrogen of the q2 -alkene complexes was
abstracted by [Ph3C ] [BF4 ] ; (2) the v2 -diene complex was protonated
by HBF, ; (3) the t)2-3-methoxyalkenec omplex was protonated by HBFI.
Fast exo-endo interconversion between two isomers exo and endo
[cp*R e ( ~ 0(q)3 ~-C 3H5) I* was observed by magnetization-t ransfer
experiments.
Three heterobinuclear complexes cp* (CO) Re (p2 - CO)p 1r (CO) cp* ,
cp (CO)R~( p2 -CO)1~r (CO) cp* and cp* (co)M~(~,- co)1~r (CO) cp* have been
synthesized and fully characterized.
To my parents
and
To my wife (Jun-Xue) and son (Wei-Wei)
ACKNOWLEDGEMENTS
The author would like t o express his sincere gratitude t o
his supervisor, Professor D. Sutton, for his continued guidance,
advice and encouragement throughout the course of this work.
The author expresses his sincere thanks to:
Professor F.W.B. Einstein, Dr. R.J. Batchelor and Dr. R.H.
Jones for the crystal structure determinations involved in this
thesis;
Dr. L. Peterson for his helpful discussions;
Dr. A. Tracey and Mrs. M. Tracey for their collaboration in
the NMR studies; and
Dr. N. Lowe for proof reading this thesis.
The author also wishes t o thank Mr. Greg Owen and Mr. Miki
Yang for a l l their extra time, and Mr. Ramzi Hader for assistance
with heterobimetallic complex syntheses.
TABLE OF CONTENTS
Page
Title i
Approval ii
Abstract iii
Dedication v
Acknowledgements vi
Table of Contents vii
Abbreviations X
List of Figures xi
List of Tables xiv
Chapter I Review of Carbon Hydrogen Activation by 1
Organometallic Complexes
1.1. Introduction
1.2. Nature of Transition-Metal Systems Activating
C-H Bonds
1.3. An Outline of C-H Activation in Organometallic
Chemistry
1.4. Advances in the Study of C-H Activation 12
(i) C-H Activation by Oxidative Addition 12
(ii) Selectivity of C-H Activation 16
(iii) g2 -Arene Intermediate 19
(iv) Functionalization of C-H Bonds by Transition- 21
Metal Systems
Chapter I1 Synthesis and Characterization of Pentamethyl- 24
-vii-
cyclopentadienyl(a1kene) Complexes of Rhenium
2.1. Introduction
2.2. Synthesis
2.3. Characterization
2.4. Chemical Reactions
2.5. Discussion
2.5.1. IH NMR Spectroscopy
2.5.2. Mass Spectra
(i) Linear Alkene Complexes
(ii) Cyclic Alkene Complexes
(iii) Diene Complexes
( iv) Others
(v> Summary
2.6. Conclusion
2.7. Experimental Section
Chapter I11 Photochemical Allylic C-H Activation in a
c ~ * RSy~st em
Introduction
Synthesis
Characterization
Chemical Reactions
Discussion
X-ray Structures of [15a]exo and [15b]endo
IR Spectroscopy
H NMR Spectroscopy
Mass Spectroscopy
-viii-
3.5.5. Exo-endo Interconversion of 13 -Ally1 Group
3.5.6. Chemical Reactions
3.6. Conclusion
3.7. Experimental Section
Chapter IV Syntheses, Characterizations and Reactions
of Cationic q3 -Ally1 Complexes of Rhenium
4.1. Introduction
4.2. Synthesis
4.3. Characterization
4.4. Chemical Reactions
Discussion
'H NMR Spectra
Syntheses and Reactions
4.6. Conclusion
4.7. Experimental Section
Chapter V Synthesis and Characterization of Hetero-
bimetallic, Metal-Metal Bonded Complexes
5.1. Introduction
5.2. Synthesis and Characterization
5.3. Discussion
5.3.1. Synthesis
5.3.2. Characterization
5.3.3. X-ray Structure of Compound [26]
5.4. Experimental Section
References