Synthesis, structure and reactivity of chiral cyclopentadienylruthenium(II) complexes

Wong, DM

Abstract

This thesis concerns the preparation, structural, and reactivity studies of new
chiral monometallic cyclopentadienylruthenium(n) complexes exhibiting a combination
of metal-centred and ligand-derived chirality.
The introductory chapter provides an overview of the types of chiral
organometallic complexes previously reported, general methods of synthesis,
separation, and techniques for stereochemical determination.
In the second chapter, a range of chiral cyclopentadienylruthenium(n) amine
complexes {[(Ti 5 -C 5 H5)Ru(PPh3 )(L)(NHRR')]PF6 (L = CN*Bu, CO)}, prepared from
their precursor halides ((±)-[(rj 5 -C 5 H5)Ru(PPh 3 )(L)X], X = Cl or I) via treatment with
various amines (1°: cyclohexylamine, S(-)-a-methylbenzylamine, /?(-)-1-cyclohexylethylamine,
(±)-l-(l-naphthyl)ethylamine; 2°: diethylamine, 5(-)-A^-methyl-l-phenylethylamine)
in the presence of a halide abstractor are described. Various reactions and
decomplexations are discussed.
The third chapter contains the synthesis and reactions of sulphur donor
complexes (dimethyl sulphoxide, (±)-2-methyl-l-butanethiol) which are prepared
analogously. An X-ray crystal structure determined for (±)-[(rj 5 -C 5 H5)Ru(PPh 3 )-
(CNtBu)(Me 2 SO)]PF6 is also discussed.
The fourth chapter describes the preparation of the chiral ligand S(-)-oc-methylbenzylisonitrile
by Phase-Transfer Hoffmann Isocarbylamine reaction. Complexes
(^^c,^5c)-[(Ti 5 -C5H 5 )Ru(PPh 3 )(CNCHMePh)Cl] and (RRu Sc3Ru Sc )-[(T} 5 -C 5 H 5 )Ru-
(PPh 3 )(CNt Bu)(CNCHMePh)(NH 3 )]PF6 , which were subsequently prepared by known
procedures, and the X-ray crystal structure determined for the latter complex is also
presented.
Alkoxycarbene complexes (±)-[(Ti 5 -C 5 H5)Ru(PPh 3 )(CNtBu)(L)]PF6 (L =
C{OMe}CH2 Ph, C{CH 2 } 3 O) are presented in the fifth chapter. Methylation of the
alkoxylvinyl or metallated carbene derivatives with iodomethane are discussed for the
acyclic and cyclic systems respectively.
The sixth chapter contains attempted reactions of the halide precursor and of the
molecular dihydrogen complex (±)-[(r| 5 -C 5 H 5 )Ru(PPh 3 )(CNt Bu)(Ti 2 -H2)]PF6 (e.g.,
haloalkane, aldehydes, ketones, alkene).
Complexes containing an asymmetrically disubstituted rc-bonded ligand, TJ -1-
ethyl-3-methylcyclopentadiene which induces planar chirality, e.g., [(r| 5 -l-Et-3-Me-
C 5 H 3 )Ru(PPh3 )(L)Cl] (L - PPh 3 , CN'Bu, CO, P(OMe) 3 ) and l(r| 5 -l-Et-3-Me-C 5 H3 )Ru-
(PPh3 )(L)(NH 2 CHMePh)]PF6 (L = CN'Bu, P(OMe) 3 ) are described in the seventh
chapter.
Spontaneous resolution by crystallisation are reported as assayed from X-ray
crystal structures determined for single crystals (i.e., (5««)-[(r| 5 -C5H5)Ru(PPh3 )-
(CNtBu)(NH2Cy)]PF6 and (RpiSRuScH(r( 5 - l-Et-3-Me-C 5 H 3 )Ru(PPh3 )(CNtBu)(NH2 CHMePh)]
PF6). These are discussed in chapters 2 and 7 respectively.
The eighth chapter contain the experimental details for chapters 2 to 7.

Citation

Wong, D. Synthesis, structure and reactivity of chiral cyclopentadienylruthenium(II) complexes. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Jun 29, 2021
• Additional Information: Funders : Engineering and Physical Sciences Research Council (EPSRC)
• Award Date: Sep 1, 1996