1988 | OriginalPaper | Buchkapitel
The Behaviour of a Dialuminoxane and Distannoxanes towards Organic Molecules
verfasst von : Hitosi Nozaki, Junzo Otera
Erschienen in: Organometallics in Organic Synthesis
Verlag: Springer Berlin Heidelberg
Enthalten in: Professional Book Archive
Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.
Wählen Sie Textabschnitte aus um mit Künstlicher Intelligenz passenden Patente zu finden. powered by
Markieren Sie Textabschnitte, um KI-gestützt weitere passende Inhalte zu finden. powered by
The concept of the combined acid-base attack is exemplified by the behaviour of organoaluminium amides towards trisubstituted oxiranes, which are converted into allylic alcohols. The coordination of the reagent on the oxirane oxygen occurs in a fast equilibrium, whereas the nitrogen lone pair thus activated abstracts a proton from the ∝-carbon on the same side as the ring hydrogen, and the nucleophilic attack is rate-and product-determining. Furthermore, the above concept is extended to the reaction of neryl diethyl phosphate with (iBu2Al) 2O, which involves the intermediary ion-pair containing neryl cation and phosphate-dialuminoxane complex anion. The extensively delocalized negative charge in the anion complex leaves a nearly naked neryl carbocation behind, the cyclization of which is followed by deprotonation. The latter stage of nucleophilic attack is again the real rate and product-determining step. The concept of the combined acid-base attack is exemplified by the behaviour of organoaluminium amides towards trisubstituted oxiranes, which are converted into allylic alcohols. The coordination of the reagent on the oxirane oxygen occurs in a fast equilibrium, whereas the nitrogen lone pair thus activated abstracts a proton from the oc-carbon on the same side as the ring hydrogen, and the nucleophilic attack is rate-and product-determining. Furthermore, the above concept is extended to the reaction of neryl diethyl phosphate with (iBu2Al)20, which involves the intermediary ion-pair containing neryl cation and phosphate-dialuminoxane complex anion. The extensively delocalized negative charge in the anion complex leaves a nearly naked neryl carbocation behind, the cyclization of which is followed by deprotonation. The latter stage of nucleophilic attack is again the real rate- and product-determining step.