Source:http://linkedlifedata.com/resource/pubmed/id/21254425
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| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2
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| pubmed:dateCreated |
2011-1-21
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| pubmed:abstractText |
A method is presented for the asymmetric synthesis of chiral ruthenium polypyridyl complexes that starts from racemic cis-[Ru(pp)(2)Cl(2)] (pp=2,2'-bipyridine or 1,10-phenanthroline ligands). The chiral bidentate ligands (R)-2-(isopropylsulfinyl)phenol, (R)-SO, and preferably the more electron-rich derivative (R)-2-(isopropylsulfinyl)-4-methoxyphenol, (R)-SO', serve as convenient chiral auxiliaries for the conversion of racemic starting complexes (1a: pp=2,2'-bipyridine; 1b: pp=5,5'-dimethyl-2,2'-bipyridine; c: pp=1,10-phenanthroline) into single diastereomers ?-[Ru(pp)(2){(R)-SO}]PF(6) (?-(S)-2a-c) or ?-[Ru(pp)(2){(R)-SO'}]PF(6) (?-(S)-2a') under a thermodynamically controlled dynamic transformation. The complexes ?-(S)-2a-c and ?-(S)-2a' themselves are direct precursors for the generation of optically active ruthenium-polypyridyl complexes by trifluoroacetic-acid-induced replacement of the sulfinylphenolate auxiliaries with bidentate pp ligands under retention of configuration, thereby affording ?-[Ru(pp)(3)](PF(6))(2) (3a-c) complexes with high enantiomeric ratios of ?98:2. In particular, by employing the methoxy-modified chiral auxiliary (R)-SO', enantiomeric ratios of >99:1 were reached. In the strategy introduced here, the high steric crowding of an octahedral coordination sphere was exploited by placing a sulfur-based stereocenter in direct proximity to the ruthenium stereocenter, thereby leading to a large difference in the stabilities of the intermediate ?-S and ?-S diastereomers and thus providing the opportunity to find suitable reaction conditions for conversion of the destabilized diastereomer into the thermodynamically more-stable one. This method should be of high practical value for the asymmetric synthesis of ruthenium-polypyridyl complexes because it allows one to use readily available racemic ruthenium complexes as starting materials.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Feb
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| pubmed:issn |
1861-471X
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| pubmed:author | |
| pubmed:copyrightInfo |
Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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| pubmed:issnType |
Electronic
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| pubmed:day |
1
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| pubmed:volume |
6
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
474-81
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| pubmed:year |
2011
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| pubmed:articleTitle |
Asymmetric coordination chemistry by chiral-auxiliary-mediated dynamic resolution under thermodynamic control.
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| pubmed:affiliation |
Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, 35043 Marburg, Germany.
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| pubmed:publicationType |
Journal Article
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