Catalysis Communications (Nov 2021)

Efficient catalytic oxidation of primary benzylic CH bonds with molecular oxygen catalyzed by cobalt porphyrins and N-hydroxyphthalimide (NHPI) in supercritical carbon dioxide

  • Wei-Jie Hu,
  • Xian-Tai Zhou,
  • Mu-Zhao Sun,
  • Hong-Bing Ji

Journal volume & issue
Vol. 159
p. 106353

Abstract

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The oxidation of benzylic CH bonds by metalloporphyrins in supercritical carbon dioxide (scCO2) has still limited. Herein, an efficient protocol of aerobic oxidation of primary benzylic CH bond by cobalt porphyrin and NHPI (N-hydroxyphthalimide) in scCO2 was established. Using toluene as model substrate, 21.6% conversion and 81.2% benzoic acid selectivity was obtained under the optimized conditions. The protocol also exhibited good tolerance towards the oxidation of various substrates with different electron property groups. Moreover, a plausible mechanism involving free radical and high-valence cobalt species was proposed.

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