Novel chiral cyclopentadienyl metal complexes
Novel chiral cyclopentadienyl metal complexes
The synthesis and applications of transition metal complexes containing cyclopentadienyl-phosphorus and amine bidentate ligands have been reviewed and the work of other research groups discussed.
The synthesis of the known three-carbon linked ligand rac[3-cyclohexyl-3-(3H-iden-1-yl)propyl]-diphenyl-phosphine 201 has been optimised. This involves the novel 1,4-catalytic addition of idenyl lithium to an α,β-unsaturated ester. Complexation with RuC12(PPh3)3 to form its ruthenium(II) complex rac-401, has also been optimised. Complete control over the induction of chirality at the metal centre and high induction of planar chirality (66% d.e.) remain. Its cationic version rac-402 has been synthesised, however, the attempted synthesis of its tetrahydroindenyl analogue rac-403 failed.
The novel three-carbon linked chiral ligand (S)-[3-cyclohexyl-3-(3H-iden-1-yl)-propyl]diphenyl-phosphine, (S)-201 has been synthesised with an overall yield of 26% after 7 steps in 98% e.e. This involved initial asymmetric hydrogenation of 330 using a chiral bidentate phosphine-ruthenium complex and was achieved in 81% yield and 99% e.e. This displacement of the secondary mesylate 335 with idene, via an SN2 mechanism, was the key step with enantiomeric purity being maintained. (S)-201 has been complexed with RuC12(PPh3)3 to form its ruthenium(Ii) complex (S)-401, with 67% d.e. induction of planar chirality and complete control over the induction of chirality at the metal centre. Its cationic version (S)-402 has been synthesised, however, the attempted synthesis of its tetrahydroindenyl analogue (S)-403 failed.
X-ray structures of five of the above organometallic complexes have been obtained, as well as size X-ray structures of intermediates formed during the syntheses of their ligands. (Formulae not provided).
University of Southampton
Wright, Peter Alan
26ab419b-0d9c-4a35-acea-6674f3bc3e95
2005
Wright, Peter Alan
26ab419b-0d9c-4a35-acea-6674f3bc3e95
Wright, Peter Alan
(2005)
Novel chiral cyclopentadienyl metal complexes.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The synthesis and applications of transition metal complexes containing cyclopentadienyl-phosphorus and amine bidentate ligands have been reviewed and the work of other research groups discussed.
The synthesis of the known three-carbon linked ligand rac[3-cyclohexyl-3-(3H-iden-1-yl)propyl]-diphenyl-phosphine 201 has been optimised. This involves the novel 1,4-catalytic addition of idenyl lithium to an α,β-unsaturated ester. Complexation with RuC12(PPh3)3 to form its ruthenium(II) complex rac-401, has also been optimised. Complete control over the induction of chirality at the metal centre and high induction of planar chirality (66% d.e.) remain. Its cationic version rac-402 has been synthesised, however, the attempted synthesis of its tetrahydroindenyl analogue rac-403 failed.
The novel three-carbon linked chiral ligand (S)-[3-cyclohexyl-3-(3H-iden-1-yl)-propyl]diphenyl-phosphine, (S)-201 has been synthesised with an overall yield of 26% after 7 steps in 98% e.e. This involved initial asymmetric hydrogenation of 330 using a chiral bidentate phosphine-ruthenium complex and was achieved in 81% yield and 99% e.e. This displacement of the secondary mesylate 335 with idene, via an SN2 mechanism, was the key step with enantiomeric purity being maintained. (S)-201 has been complexed with RuC12(PPh3)3 to form its ruthenium(Ii) complex (S)-401, with 67% d.e. induction of planar chirality and complete control over the induction of chirality at the metal centre. Its cationic version (S)-402 has been synthesised, however, the attempted synthesis of its tetrahydroindenyl analogue (S)-403 failed.
X-ray structures of five of the above organometallic complexes have been obtained, as well as size X-ray structures of intermediates formed during the syntheses of their ligands. (Formulae not provided).
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Published date: 2005
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Local EPrints ID: 465728
URI: http://eprints.soton.ac.uk/id/eprint/465728
PURE UUID: 52aba560-1c23-428c-9d59-890b1ea4ac50
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Date deposited: 05 Jul 2022 02:48
Last modified: 16 Mar 2024 20:20
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Author:
Peter Alan Wright
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