Control of the ambident reactivity of the nitrite ion
2013 (English)In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 11, no 4, 648-653 p.Article in journal (Refereed) Published
In previous studies, it was reported that a neighbouring equatorial ester group is essential for a good yield of nitrite-mediated triflate inversion, whereas with neighbouring benzyl ether groups or axial ester groups, mixtures are generally produced. In the present study, the origin of this difference was addressed. The ambident reactivity of the nitrite ion has been found to be the cause of the complex product formation observed, which can be controlled by a neighbouring equatorial ester group. Both N-attack and O-attack occur in the absence of the ester group, whereas O-attack is favoured in its presence. A neighbouring group assistance mechanism is proposed, in addition to steric effects, based on secondary interactions between the neighbouring ester group and the incoming nucleophile. High-level quantum mechanical calculations were carried out in order to delineate this effect. The theoretical results are in excellent agreement with experiments, and suggest a catalytic role for the neighbouring equatorial ester group.
Place, publisher, year, edition, pages
2013. Vol. 11, no 4, 648-653 p.
Alkyl Nitrites, Carbohydrate Epimerization, Substitution-Reactions, Hydrolysis, System, Nucleophiles, Activation, Inversion, Epoxides, Benzoate
IdentifiersURN: urn:nbn:se:kth:diva-116421DOI: 10.1039/c2ob26980eISI: 000312555800017ScopusID: 2-s2.0-84871792087OAI: oai:DiVA.org:kth-116421DiVA: diva2:589925
FunderSwedish Research Council
QC 201301212013-01-212013-01-182013-01-21Bibliographically approved