A Computational Study on the Radical Cascade Cyclization Mechanism of Synthesis of Benzo[b]oxepinones and Chromanes


Fıstıkçı M.

ChemistrySelect, vol.8, no.18, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 8 Issue: 18
  • Publication Date: 2023
  • Doi Number: 10.1002/slct.202300146
  • Journal Name: ChemistrySelect
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier
  • Keywords: Benzo[b]oxepinone, cascade radical cyclization, chromane, DFT, TBHP
  • Hakkari University Affiliated: Yes

Abstract

A computational study on the reaction mechanism of the effective synthesis of sulfonated benzo[b]oxepinones and chromanes by radical cascade cyclization is carried out employing the density functional theory (DFT). Based on our computations, the rate-determining step is the formation of arylsulfonyl radical for the reaction scheme. Our calculations show that the reaction of 1,8- and 1,7-enynes with arylsulfonyl radical proceeds by forming more thermodynamically stable intermediates. Therefore, 1,8-enynes prefer 7-exo-trig cyclization, while 1,7-enynes prefer 6-exo-trig cyclization. Our computations are consistent with experimental results of the radical cascade cyclization of 1,8- and 1,7-enynes. Moreover, our computations show that if the reaction is carried out in a proton-free solvent, the elimination product can be obtained from the cascade radical cyclization of the 1,7-enyne.