INVESTIGADORES
MURRAY Ana Paula
artículos
Título:
Nucleophilicity Vs. Basicity In The Reaction Of Sodium T-Butoxide With B-Stannylketones
Autor/es:
ALICIA CHOPA,; ANA PAULA MURRAY
Revista:
ORGANOMETALLICS
Editorial:
American Chemical Society
Referencias:
Año: 2001 vol. 20 p. 1476 - 1478
ISSN:
0276-7333
Resumen:
Summary: The reaction of 3-stannyl-1,2,3-triphenyl- and
3-stannyl-1,3-diphenyl-2-methylpropanones with sodium
tert-butoxide in either t-BuOH or dimethyl sulfoxide
(DMSO) as solvent leads to elimination and/or substitution
products. The composition of the product mixtures
depends essentially on the nature of the ligands attached
to the tin atom, on the solvent, and also on the nature of
the substituent on C-2. Thus, â-(triphenyl), â-(bromodiphenyl),
and â-(trichlorostannyl) ketones undergo an
exclusive elimination reaction leading to an unsaturated
ketone in good to high yields (72%-96%) both in t-BuOH
and in DMSO. In the latter the reactions lead to higher
yields in shorter times. On the other hand, â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.â-(triphenyl), â-(bromodiphenyl),
and â-(trichlorostannyl) ketones undergo an
exclusive elimination reaction leading to an unsaturated
ketone in good to high yields (72%-96%) both in t-BuOH
and in DMSO. In the latter the reactions lead to higher
yields in shorter times. On the other hand, â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.â-(trichlorostannyl) ketones undergo an
exclusive elimination reaction leading to an unsaturated
ketone in good to high yields (72%-96%) both in t-BuOH
and in DMSO. In the latter the reactions lead to higher
yields in shorter times. On the other hand, â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.-96%) both in t-BuOH
and in DMSO. In the latter the reactions lead to higher
yields in shorter times. On the other hand, â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.â-(trimethylstannyl)
ketones lead to mixtures of olefins and substitution
products in t-BuOH and exclusively to substitution
products in DMSO (96%-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.-98%). Stereochemical
results suggest that the elimination reactions proceed
through an (E1cB)R mechanism.R mechanism.