| Autor: |
Bouet A; Laboratoire de Chimie Organique Fine et Hétérocyclique, UMR 6014, IRCOF, CNRS, Université et INSA de Rouen, B.P. 08, F-76131, Mont-Saint-Aignan Cédex, France., Deguest G, Heller B, Papamicaël C, Dupas G, Oudeyer S, Marsais F, Levacher V |
| Jazyk: |
angličtina |
| Zdroj: |
Organic & biomolecular chemistry [Org Biomol Chem] 2007 May 07; Vol. 5 (9), pp. 1397-404. Date of Electronic Publication: 2007 Mar 23. |
| DOI: |
10.1039/b701549f |
| Abstrakt: |
This work reports the synthesis of new axially chiral bridged 2,2'-bipyridines 1 and pyridylmonooxazolines (pymox) 2. The potential of these new axially chiral N,N-ligands was evaluated in asymmetric catalytic cyclopropanation of styrene derivatives 22a-c with diazoesters 21a,b. While 2,2'-bipyridines 1a-c afforded the corresponding cyclopropanes 23a-f in up to 65% ee, pymoxs 2a-e gave somewhat lower enantioselectivities (up to 53% ee). Both classes of ligands produced trans-cyclopropanes 23a-f as the major isomer, although with modest diasteroselectivities (56 : 44 to 78 : 22). A structure-stereoselectivity relationship study of ligands 1 and 2 identified the chiral biaryl axis as being mostly responsible for the enantioselective performances of these ligands. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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