Synthesis 2024; 56(10): 1593-1600
DOI: 10.1055/a-2242-6435
paper

K2CO3-Mediated Intramolecular Oxa-Michael Cyclization of α,β-Unsaturated Ketoximes: Synthesis of Densely Arene-Substituted 2-Isoxazolines Bearing a Quaternary Center

Ram Singh Jat
a   Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, Bandarsindri, Rajasthan-305817, India
,
Raveendrababu Kothapalli
b   SCIM Govt. College, Tanuku, West Godavari (Dist.), Andhra Pradesh-534211, India
,
M. Bhanuchandra
a   Department of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, Bandarsindri, Rajasthan-305817, India
› Institutsangaben
We gratefully acknowledge the Department of Science and Technology - Science and Engineering Research Board (DST-SERB) (EEQ/2022/000490) for research funding. We also thank Central the University of Rajasthan for support. R.S.J. thanks Council of Scientific & Industrial Research (CSIR), India for the award of a Senior Research Fellowship (CSIR-SRF).


Abstract

An efficient K2CO3-mediated intramolecular oxa-Michael cyclization of β,β-diarylated α,β-unsaturated ketoximes is described. This methodology allows access to arene-rich 2-isoxazoline derivatives bearing a quaternary center in excellent yields with an operationally simple experimental procedure. Deuterium-scrambling experiments were carried out to shed light on the reaction pathway. To demonstrate the synthetic utility of the method, a large-scale synthesis and Ullmann-type C–N bond-formation reaction between pyrazole and dibrominated isoxazoline was performed.

Supporting Information



Publikationsverlauf

Eingereicht: 12. Dezember 2023

Angenommen nach Revision: 10. Januar 2024

Accepted Manuscript online:
10. Januar 2024

Artikel online veröffentlicht:
13. Februar 2024

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