Evidence for involvement of cationic intermediate in epoxidation of chiral allylic alcohols and unfunctionalised alkenes catalysed by MnIII(quinazolinone) complexes
Özet
A pair of Mn-III(quinazolinone) complexes was prepared and evaluated in the catalytic epoxidation of the chiral allylic alcohols and unfunctionalised alkenes with iodosylbenzene. Epoxidation of chiral allylic alcohols with 1,3-allylic strain proceeded chemo- and diastereoselectively to give threo-epoxy alcohol (up to 99% d.r). Epoxidation of unfunctionalised alkenes by the proposed catalyst system proceeded nonselectively, as evidenced by the formation of isomerization and rearrangement products in the epoxidation of (Z)-stilbene. A three-step pathway involving a cationic intermediate is proposed for the formation of isomerization and rearrangement products. The fact that only products resulting from the cationic intermediate were detected in the oxidation of a mechanistic probe, (2-methoxy-3-vinylcyclopropyl)benzene, with Mn-III(quinazolinone) and PhIO substantiated the cationic oxygen transfer mechanism. (C) 2017 Elsevier Ltd. All rights reserved.
Atıf için künye
Çakıcı, M., Kılıç, H., Ulukanlı, S., & Ekinci, D. (2018). Evidence for involvement of cationic intermediate in epoxidation of chiral allylic alcohols and unfunctionalised alkenes catalysed by MnIII(quinazolinone) complexes. TETRAHEDRON, 74(1), 49–57. https://doi.org/10.1016/j.tet.2017.11.034
BibTeX
@article{cakici2018-66300,
author = {Çakıcı, Murat and Kılıç, Hamdullah and Ulukanlı, Sabri and Ekinci, Duygu},
title = {Evidence for involvement of cationic intermediate in epoxidation of chiral allylic alcohols and unfunctionalised alkenes catalysed by MnIII(quinazolinone) complexes},
journal = {TETRAHEDRON},
year = {2018},
volume = {74},
number = {1},
pages = {49--57},
issn = {0040-4020},
doi = {10.1016/j.tet.2017.11.034},
url = {https://akademik.atauni.edu.tr/yayinlar/66300-evidence-for-involvement-of-cationic-intermediate-in-epoxidation-of-chiral}
}