P-chiral, monodentate ferrocenyl phosphines, novel ligands for asymmetric catalysis.
J Org Chem
; 68(1): 156-66, 2003 Jan 10.
Article
em En
| MEDLINE
| ID: mdl-12515474
Eight P-chiral monodentate ferrocenyl phosphines (1a-h) were prepared in high enantiomeric excess (>95% ee in most cases) by way of an ephedrine-based oxazaphospholidine borane complex. Primary alkyl, secondary alkyl, and substituted aromatic substituents were successfully introduced at the phosphorus center, along with ferrocenyl and phenyl groups, generating phosphines of the general structure FcP(Ph)(R) (Fc = ferrocenyl, R = aryl, alkyl). The synthetic route employed provides facile access to a previously undeveloped class of chiral monophosphines. These compounds were evaluated as ligands in asymmetric catalytic reductive coupling of alkynes and aldehydes and were found to provide the desired chiral allylic alcohols with good regioselectivity and ee in many cases and with complete (E)-selectivity (>98:2) in all cases.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfinas
/
Boranos
/
Compostos Ferrosos
Idioma:
En
Revista:
J Org Chem
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Estados Unidos