On the mechanism of the directed ortho and remote metalation reactions of N,N-dialkylbiphenyl 2-carboxamides.
Org Lett
; 12(1): 68-71, 2010 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-19994874
ABSTRACT
A study concerning the mechanism of the LDA-mediated ortho and remote metalation of N,N-dialkyl-2-biphenyl carboxamides (e.g., 4a) is reported. On the basis of site-selective lithiation/electrophile quench experiments, including deuteration, the LDA metalation of 4 is proposed to involve initial amide-base complexation (CIPE) and equilibrium formation of 5, whose fast reaction with an in situ electrophile (TMSCl) to afford 6 prevents its equilibration with 7. In the absence of an electrophile, 5 undergoes equilibration via 4a with 7, whose fate is instantaneous cyclization to a stable tetrahedral carbinolamine oxide 8 which, only upon hydrolysis, affords fluorenone (3).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos de Bifenilo
/
Amidas
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article