Toolbox approach to the search for effective ligands for catalytic asymmetric Cr-mediated coupling reactions.
J Am Chem Soc
; 131(42): 15387-93, 2009 Oct 28.
Article
em En
| MEDLINE
| ID: mdl-19795862
ABSTRACT
Chromium catalysts derived from chiral sulfonamides represented by A effect the couplings of aldehydes with vinyl, allyl, or alkyl halides. With three distinct sites for structural modification, A affords access to a structurally diverse pool of chiral sulfonamides. The Cr catalysts derived from these sulfonamides exhibit a broad range of catalyst-substrate matching profiles. A strategy is presented to search for a satisfactory chiral sulfonamide for a given substrate. In order to demonstrate the generality and effectiveness of this approach, five diverse C-C bond-forming cases have been selected from the halichondrin synthesis. For each of the cases, two ligands have been deliberately searched for, to induce the formation of (R)- and (S)-alcohols, respectively, at the arbitrarily chosen efficiency level of ">or=80% yield with >or=201 stereoselectivity in the presence of
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cromo
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Estados Unidos