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Ultrasound‐Promoted Radical Synthesis of 5‐Methylselanyl‐4,5‐dihydroisoxazoles
Author(s) -
Araujo Daniela R.,
Lima Yanka R.,
Barcellos Angelita M.,
Silva Márcio S.,
Jacob Raquel G.,
Lenardão Eder J.,
Bagnoli Luana,
Santi Claudio,
Perin Gelson
Publication year - 2020
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201901611
Subject(s) - chemistry , radical , homolysis , sonication , solvent , radical cyclization , selectivity , organic chemistry , medicinal chemistry , catalysis , chromatography
The ultrasound‐promoted synthesis of 5‐methylselanyl‐4,5‐dihydroisoxazoles through the radical cyclization of unsaturated oximes with diaryl diselenides using Oxone® as an oxidant and ethanol as the solvent is described. The key step of the reaction is the ultrasound‐initiated homolytic cleavage of KHSO 5 , leading to the formation of sulfate and hydroxyl radicals. The reactions proceed efficiently using several oximes and diselenides containing both electron‐withdrawing and electron‐donating groups in the aromatic ring. The positive effect of the sonication resulted in high selectivity, short reaction times (15 to 40 min) and moderate to excellent yields of the expected products (60–93 %).