Bi(OTf)3-, TfOH-, and TMSOTf-mediated, one-pot epoxide rearrangement, addition, and intramolecular silyl-modified Sakurai (ISMS) cascade toward dihydropyrans: comparison of catalysts and role of Bi(OTf)3.
J Org Chem
; 76(22): 9269-77, 2011 Nov 18.
Article
em En
| MEDLINE
| ID: mdl-21916500
ABSTRACT
Catalytic quantities of bismuth(III) triflate efficiently initiate the rearrangement of epoxides to aldehydes, which subsequently react with (Z)-δ-hydroxyalkenylsilanes to afford 2,6-disubstituted 3,6-dihydro-2H-pyrans. Isolated yields of desired products using Bi(OTf)(3) were compared with yields obtained when the reactions were run with TfOH and TMSOTf in the presence and absence of several additives. These studies, as well as NMR spectroscopic analyses, indicate an initial Lewis acid/base interaction between Bi(OTf)(3) and substrates providing TfOH in situ.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Piranos
/
Silanos
/
Mesilatos
/
Compostos de Epóxi
Idioma:
En
Revista:
J Org Chem
Ano de publicação:
2011
Tipo de documento:
Article