Nitrile-Promoted Alkene Epoxidation with Urea–Hydrogen Peroxide (UHP)

Abstract

An efficient method for alkene epoxidation has been studied systematically using benzonitrile and the complex urea–hydrogen peroxide (UHP), which is an anhydrous form of hydrogen peroxide and has the potential to release hydrogen peroxide in a controlled manner and thus avoid the need to slowly add aqueous H₂O₂ to the reaction mixture. The absence of water in the reaction media was also beneficial, because it minimized undesired reactions of the oxidized products. A range of alkenes was epoxidized by this method, providing yields ranging from 79% to 96%.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.

GRAPHICAL ABSTRACT

Keywords:

• Alkenes
• nitrile
• oxidation
• Payne epoxidation
• peroxycarboximidic acid
• urea–hydrogen peroxide (UHP)

ACKNOWLEDGMENTS

We thank the National Natural Science Foundation of China (21076183, 21006087), the Fundamental Research Funds for the Central Universities (2011QNA4018), and the Key Innovation Group of Zhejiang Province (2009R50002) for financial support.

Notes

^a The substrate cyclohexene was treated with UHP (3.50 equiv.), nitrile (1.10 equiv.), and KHCO₃ (0.2 equiv.) at 30 °C in MeOH.

^b Conversion and yield determined by GC.

^a The substrate cyclohexene was treated with UHP (3.50 equiv.), benzonitrile (1.10 equiv.), and KHCO₃ (0.2 equiv.) at 30 °C.

^b Conversion and yield determined by GC.

^a The substrate cyclohexene was treated with UHP (3.50 equiv.) and benzonitrile (1.10 equiv.) at 30 °C in methanol, 4 h.

^b Conversion and yield determined by GC.

^a The substrate cyclohexene was treated with benzonitrile (1.10 equiv.) and KHCO₃ (0.2 equiv.) at 30 °C in MeOH, 4 h.

^b Conversion and yield determined by GC.

^a The substrate cyclohexene was treated with UHP (3.50 equiv.), benzonitrile (1.10 equiv.), and KHCO₃ (0.2 equiv.).

^b Conversion and yield determined by GC.

^a The substrate (10.0 mmol) was treated with UHP (3.50 equiv.) or 30% H₂O₂ (4.00 equiv.), benzonitrile (1.10 equiv.), and KHCO₃ (0.2 equiv.).

^b Yield determined by GC.

^a The substrate (10.0 mmol) was treated with UHP (3.50 equiv.), benzonitrile (1.10 equiv.), and KHCO₃ (0.2 equiv.).

^b Isolated yield.