1,3-Dipolar Cycloaddition Reactivities of Perfluorinated Aryl Azides with Enamines and Strained Dipolarophiles
2015 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 137, no 8, 2958-2966 p.Article in journal (Refereed) Published
The reactivities of enamines and predistorted (strained) dipolarophiles toward perfluoroaryl azides (PFAAs) were explored experimentally and computationally. Kinetic analyses indicate that PFAAs undergo (3 + 2) cycloadditions with enamines up to 4 orders of magnitude faster than phenyl azide reacts with these dipolarophiles. DFT calculations were used to identify the origin of this rate acceleration. Orbital interactions between the cycloaddends are larger due to the relatively low-lying LUMO of PFAAs. The triazolines resulting from PFAAenamine cycloadditions rearrange to amidines at room temperature, while (3 + 2) cycloadditions of enamines and phenyl azide yield stable, isolable triazolines. The 1,3-dipolar cycloadditions of norbornene and DIBAC also show increased reactivity toward PFAAs over phenyl azide but are slower than enamineazide cycloadditions.
Place, publisher, year, edition, pages
2015. Vol. 137, no 8, 2958-2966 p.
IdentifiersURN: urn:nbn:se:kth:diva-164457DOI: 10.1021/ja511457gISI: 000350614700029PubMedID: 25553488ScopusID: 2-s2.0-84924311187OAI: oai:DiVA.org:kth-164457DiVA: diva2:807257
QC 201504232015-04-232015-04-172015-09-03Bibliographically approved