Beckmann rearrangement of 15N-cyclohexanone oxime on zeolites silicalite-1, H-ZSM-5, and H-[B]ZSM-5 studied by solid-state NMR spectroscopy

V R Reddy Marthala; Yijiao Jiang; Jun Huang; Wei Wang; Roger Gläser; Michael Hunger

doi:10.1021/ja066392c

Beckmann rearrangement of 15N-cyclohexanone oxime on zeolites silicalite-1, H-ZSM-5, and H-[B]ZSM-5 studied by solid-state NMR spectroscopy

J Am Chem Soc. 2006 Nov 22;128(46):14812-3. doi: 10.1021/ja066392c.

Authors

V R Reddy Marthala¹, Yijiao Jiang, Jun Huang, Wei Wang, Roger Gläser, Michael Hunger

Affiliation

¹ Institute of Chemical Technology, University of Stuttgart, D-70550 Stuttgart, Germany.

PMID: 17105284
DOI: 10.1021/ja066392c

Abstract

By means of solid-state 15N NMR spectroscopy, evidence for the formation of nitrilium ions as intermediates of the Beckmann rearrangement of 15N-cyclohexanone oxime to epsilon-caprolactam on silicalite-1, H-ZSM-5, and H-[B]ZSM-5 is reported. The zeolites under study are characterized by different acid strengths (silicalite-1 < H-[B]ZSM-5 < H-ZSM-5). Depending on the nature of catalytically active surface OH groups, reactant and product molecules exist in the nonprotonated or protonated state. In addition, formation of byproducts such as 5-cyano-1-pentene and epsilon-aminocapric acid as a result of dehydration and hydrolysis of the reactant and product molecules, respectively, were observed.